This one gave me some headache, but as always, looking back the solution is pretty obvious.

Using WPF, in a MVVM design pattern, I have a ListView bound to a ObservableCollection. Straight forward senario.

XAML:

<ListView Name="lvCustomerSearchResults" ItemsSource="{Binding CustomerSearchResults}" SelectedItem="{Binding SelectedCustomer}" ...

ViewModel:

public async Task<AOTaskResult<List<CustomerSearchResultEntity>>> SearchCustomers(string cvrNo, Statuses? status = null, DateTime? fromDate = null, DateTime? toDate = null)
{
    return await Task.Run(() =>
    {
        AOTaskResult<List<CustomerSearchResultEntity>> result = new AOTaskResult<List<CustomerSearchResultEntity>>();
        try
        {
            result.Response = _repository.LstCustomers(cvrNo, status, fromDate, toDate, out List<NezCusCustomerDTO> dtos);
            if (result.Response.Success)
            {
                result.Result = dtos.Select(d => LocalMapping.ToCustomerSearchResultEntity(d)).ToList();
            }
        }
        catch (Exception ex) { CheckTaskException(ex); }
        return result;
    });
}

Trouble is when I click an item in the ListWiew I get a “Must create DependencySource on same Thread as the DependencyObject”-exception. It turns out that the reason I get this exception is that I created the items in the ObservableCollection on another thread than the main-thread. So, obviously, the solution is to create the the ObservableCollection items on the main-thread:

public async Task<AOTaskResult<List<CustomerSearchResultEntity>>> SearchCustomers(string cvrNo, Statuses? status = null, DateTime? fromDate = null, DateTime? toDate = null)
{
    AOTaskResult<List<CustomerSearchResultEntity>> result = new AOTaskResult<List<CustomerSearchResultEntity>>();
    List<NezCusCustomerDTO> dtos = null;

    await Task.Run(() =>
    {
        try
        {
            Busy = true;
            result.Response = _repository.LstCustomers(cvrNo, status, fromDate, toDate, out dtos);

            Busy = false;
        }
        catch (Exception ex) { CheckTaskException(ex); }
    });
    if (dtos != null && result.Response.Success)
    {
        result.Result = dtos.Select(d => LocalMapping.ToCustomerSearchResultEntity(d)).ToList();
    }
    return result;
}

 IMO, the code is not as clean ... but it works :-)

As always feel to ask or comment.

Her follows a simple WPF DataGrid.

In the Visual Studio Design view it look like this:

The DefaultButtonStyle and DefaultDataGrid style can be found elsewhere in this blog.

Ill include the XAML for the entire Window.

<Window x:Class="Ellab.Main.Sessions.Chamber.WPFUnitSelection.UnitSelectionView"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:Ellab.Main.Sessions.Chamber.WPFUnitSelection"
        mc:Ignorable="d"
        Title="{Binding Title}" x:Name="MainWindow" Height="300" Width="750">
    <Window.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="pack://application:,,,/Ellab.WPF;component/View/Styles/ButtonStyle.xaml"/>
                <ResourceDictionary Source="pack://application:,,,/Ellab.WPF;component/View/Styles/DataGridStyle.xaml"/>
                <ResourceDictionary Source="MvvmResources.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Window.Resources>
    <Grid Background="{Binding Background, FallbackValue=Red}">
        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="40"/>
        </Grid.RowDefinitions>
        <DataGrid Grid.Row="0" ItemsSource="{Binding Rows, FallbackValue=AllTheSmartRows}" Style="{StaticResource DefaultDataGrid}" HeadersVisibility="Column" AutoGenerateColumns="False" VerticalAlignment="Top" SelectionMode="Single" SelectionUnit="FullRow" SelectedItem="{Binding SelectedItem}">
            <DataGrid.RowStyle>
                <Style TargetType="{x:Type DataGridRow}">
                    <EventSetter Event="MouseLeftButtonDown" Handler="DataGrid_MouseLeftButtonDown"/>
                    <Style.Triggers>
                        <Trigger Property="IsSelected" Value="True">
                            <Setter Property="Background" Value="#FF009CDD" />
                        </Trigger>
                    </Style.Triggers>
                </Style>
            </DataGrid.RowStyle>
            <DataGrid.Columns>
                <DataGridTextColumn Header="{Binding UnitIDHeader, FallbackValue=ID}" Binding="{Binding UnitID, FallbackValue=ID}" MinWidth="75" Width="Auto" IsReadOnly="True"/>
                <DataGridTextColumn Header="{Binding TypeHeader, FallbackValue=Type}" Binding="{Binding Type, FallbackValue=Type}" MinWidth="75" Width="Auto" IsReadOnly="True"/>
                <DataGridTextColumn Header="{Binding UnitTypeHeader, FallbackValue=Unit Type}" Binding="{Binding UnitType, FallbackValue=Unit}" MinWidth="75" Width="Auto" IsReadOnly="True"/>
                <DataGridTextColumn Header="{Binding NameHeader, FallbackValue=Name}" Binding="{Binding Name, FallbackValue=Name}" MinWidth="125" Width="Auto" IsReadOnly="True"/>
                <DataGridTextColumn Header="{Binding DescriptionHeader, FallbackValue=Description}" Binding="{Binding Description, FallbackValue=Description}" MinWidth="25" Width="*" IsReadOnly="True"/>
            </DataGrid.Columns>
        </DataGrid>
        <Grid Grid.Row="1" Background="White" HorizontalAlignment="Stretch" VerticalAlignment="Bottom" Height="40">
            <StackPanel DockPanel.Dock="Bottom" Orientation="Horizontal" HorizontalAlignment="Right">
                <Button Margin="5" Command="{Binding HelpClickedCommand}" Width="30" Style="{StaticResource DefaultButtonStyle}" Background="#FF123F74">
                    <Image Source="../../Resources/Help.png"/>
                </Button>
                <Button Margin="5" Content="{Binding ViewButtonContent, FallbackValue=#View}" Command="{Binding ViewClickedCommand}" Style="{StaticResource DefaultButtonStyle}" Visibility="{Binding ViewVisible}" MinWidth="75"/>
                <Button Margin="5" Content="{Binding AddNewButtonContent, FallbackValue=#Add New}" Command="{Binding AddNewClickedCommand}" Style="{StaticResource DefaultButtonStyle}" Visibility="{Binding AddNewVisible}" MinWidth="75"/>
                <Button Margin="5" Content="{Binding EditButtonContent, FallbackValue=#Edit}" Command="{Binding EditClickedCommand}" Style="{StaticResource DefaultButtonStyle}" Visibility="{Binding EditVisible}" MinWidth="75"/>
                <Button Margin="5" Content="{Binding RemoveButtonContent, FallbackValue=#Remove}" Command="{Binding RemoveClickedCommand}" Style="{StaticResource DefaultButtonStyle}" Visibility="{Binding RemoveVisible}" MinWidth="75"/>
                <Button Margin="5" Content="{Binding ImportButtonContent, FallbackValue=#Import}" Command="{Binding ImportClickedCommand}" Style="{StaticResource DefaultButtonStyle}" Visibility="{Binding ImportVisible}" MinWidth="75"/>
                <Button Margin="5" Content="{Binding ExportButtonContent, FallbackValue=#Export}" Command="{Binding ExportClickedCommand}" Style="{StaticResource DefaultButtonStyle}" Visibility="{Binding ExportVisible}" MinWidth="75"/>
                <Button Margin="5" Content="{Binding OKButtonContent, FallbackValue=#OK}" Command="{Binding OKClickedCommand}" Style="{StaticResource DefaultButtonStyle}" Visibility="{Binding OKVisible}" IsDefault="True" MinWidth="75"/>
                <Button Margin="5" Content="{Binding CloseButtonContent, FallbackValue=#Close}" Command="{Binding CloseClickedCommand}" Style="{StaticResource DefaultButtonStyle}" Visibility="{Binding CloseVisible}" IsCancel="True" MinWidth="75"/>
            </StackPanel>
        </Grid>
    </Grid>
</Window>

Allthough using the MVVM design patten, I've opted to handel  event in the codebehind, as in my opinion this is View releated. Here is the event handler

namespace Ellab.Main.Sessions.Chamber.WPFUnitSelection
{
    /// <summary>
    /// Interaction logic for UnitSelectionView.xaml
    /// </summary>
    public partial class UnitSelectionView : Window
    {
        private UnitSelectionView()
        {
            InitializeComponent();
        }

        public UnitSelectionView(UnitSelectionViewModel mainContext)
            : this()
        {
            DataContext = mainContext;
        }
        private void DataGrid_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            DataGridRow clickedRos = sender as DataGridRow;
            clickedRos.IsSelected = true;
        }
    }
}

As always, feel free to comment, or ask.

Getting an ancestor property value can be done by binding to its element name. Here's an example

<Grid Width="{Binding Width}" Margin="{Binding Margin}">
	<Border BorderBrush=" #FF17447E" BorderThickness="5">
		<StackPanel Name="MainStackPanel" Orientation="Vertical">
			<ScrollViewer Height="{Binding ElementName=MainStackPanel, Path=ActualHeight}">
				<ItemsControl ItemsSource="{Binding Rows, FallbackValue=Rows}" Background="Transparent">
					<ItemsControl.ItemsPanel>
						<ItemsPanelTemplate>
							<StackPanel Orientation="Vertical"/>
						</ItemsPanelTemplate>
					</ItemsControl.ItemsPanel>
					<ItemsControl.ItemTemplate>
						<DataTemplate>
							<ContentPresenter Content="{Binding}" Height="30"/>
						</DataTemplate>
					</ItemsControl.ItemTemplate>
				</ItemsControl>
			</ScrollViewer>
		</StackPanel>
	</Border>
</Grid>

As always, feel free to comment, or ask

There are of course a lot of ways to collapse a XAML TextBlock, but here is one using a style.

<TextBlock Text="{Binding Path=DescriptiveText}">
	<TextBlock.Style>
		<Style TargetType="TextBlock">
			<Style.Triggers>
				<Trigger Property="Text" Value="{x:Null}">
					<Setter Property="Visibility" Value="Collapsed" />
				</Trigger>
				<Trigger Property="Text" Value="">
					<Setter Property="Visibility" Value="Collapsed" />
				</Trigger>
			</Style.Triggers>
		</Style>
	</TextBlock.Style>
</TextBlock>

As always, feel free to comment, or ask.

This is a small class that implements ICommand

public class RelayCommand : ICommand
{
	#region Fields
	private readonly Action<object> execute;
	private readonly Predicate<object> canExecute;
	#endregion Fields

	#region Constructors
	public RelayCommand(Action<object> execute, Predicate<object> canExecute = null)
	{
		if (execute == null)
			throw new ArgumentNullException("execute");

		this.execute = execute;
		this.canExecute = canExecute;
	}
	#endregion Constructors

	#region ICommand Members
	[DebuggerStepThrough]
	public bool CanExecute(object parameter)
	{
		return canExecute == null ? true : canExecute(parameter);
	}

	public event EventHandler CanExecuteChanged
	{
		add { CommandManager.RequerySuggested += value; }
		remove { CommandManager.RequerySuggested -= value; }
	}

	public void Execute(object parameter)
	{
		execute(parameter);
	}
	#endregion ICommand Members
}

As always, feel free to comment, or ask.

This post is about how control events, like MouseDoubleClick, MouseEnter ect., can be handled in a MVVM design

First a general Behaviour class

public static partial class Behaviours
{
	public static class EventBehaviourFactory
	{
		public static DependencyProperty CreateCommandExecutionEventBehaviour(RoutedEvent routedEvent, string propertyName, Type ownerType)
		{
			DependencyProperty property = DependencyProperty.RegisterAttached(propertyName, typeof(ICommand), ownerType,
				new PropertyMetadata(null,
					new ExecuteCommandOnRoutedEventBehaviour(routedEvent).PropertyChangedHandler));

			return property;
		}

		/// <summary>
		/// An internal class to handle listening for an event and executing a command,
		/// when a Command is assigned to a particular DependencyProperty
		/// </summary>
		private class ExecuteCommandOnRoutedEventBehaviour : ExecuteCommandBehaviour
		{
			private readonly RoutedEvent _routedEvent;

			public ExecuteCommandOnRoutedEventBehaviour(RoutedEvent routedEvent)
			{
				_routedEvent = routedEvent;
			}

			/// <summary>
			/// Handles attaching or Detaching Event handlers when a Command is assigned or unassigned
			/// </summary>
			/// <param name="sender"></param>
			/// <param name="oldValue"></param>
			/// <param name="newValue"></param>
			protected override void AdjustEventHandlers(DependencyObject sender, object oldValue, object newValue)
			{
				UIElement element = sender as UIElement;
				if (element == null) { return; }

				if (oldValue != null)
				{
					element.RemoveHandler(_routedEvent, new RoutedEventHandler(EventHandler));
				}

				if (newValue != null)
				{
					element.AddHandler(_routedEvent, new RoutedEventHandler(EventHandler));
				}
			}

			protected void EventHandler(object sender, RoutedEventArgs e)
			{
				HandleEvent(sender, e);
			}
		}

		internal abstract class ExecuteCommandBehaviour
		{
			protected DependencyProperty _property;
			protected abstract void AdjustEventHandlers(DependencyObject sender, object oldValue, object newValue);

			protected void HandleEvent(object sender, EventArgs e)
			{
				DependencyObject dp = sender as DependencyObject;
				if (dp == null)
				{
					return;
				}

				ICommand command = dp.GetValue(_property) as ICommand;

				if (command == null)
				{
					return;
				}

				if (command.CanExecute(e))
				{
					command.Execute(e);
				}
			}

			/// <summary>
			/// Listens for a change in the DependencyProperty that we are assigned to, and
			/// adjusts the EventHandlers accordingly
			/// </summary>
			/// <param name="sender"></param>
			/// <param name="e"></param>
			public void PropertyChangedHandler(DependencyObject sender, DependencyPropertyChangedEventArgs e)
			{
				// the first time the property changes,
				// make a note of which property we are supposed
				// to be watching
				if (_property == null)
				{
					_property = e.Property;
				}

				object oldValue = e.OldValue;
				object newValue = e.NewValue;

				AdjustEventHandlers(sender, oldValue, newValue);
			}
		}
	}
}

The ControlEventBehaviour class

public class ControlEventBehaviour
{
	#region Button
	public static readonly DependencyProperty MouseEnterCommand = Behaviours.EventBehaviourFactory.CreateCommandExecutionEventBehaviour
			 (Button.MouseEnterEvent, "MouseEnterCommand", typeof(ControlEventBehaviour));

	public static void SetMouseEnterCommand(DependencyObject o, ICommand value)
	{
		o.SetValue(MouseEnterCommand, value);
	}

	public static ICommand GetMouseEnterCommand(DependencyObject o)
	{
		return o.GetValue(MouseEnterCommand) as ICommand;
	}

	public static readonly DependencyProperty MouseLeaveCommand = Behaviours.EventBehaviourFactory.CreateCommandExecutionEventBehaviour
		 (Button.MouseLeaveEvent, "MouseLeaveCommand", typeof(ControlEventBehaviour));

	public static void SetMouseLeaveCommand(DependencyObject o, ICommand value)
	{
		o.SetValue(MouseLeaveCommand, value);
	}

	public static ICommand GetMouseLeaveCommand(DependencyObject o)
	{
		return o.GetValue(MouseLeaveCommand) as ICommand;
	}

	public static readonly DependencyProperty MouseDoubleClickCommand = Behaviours.EventBehaviourFactory.CreateCommandExecutionEventBehaviour
		 (Button.MouseDoubleClickEvent, "MouseDoubleClickCommand", typeof(ControlEventBehaviour));

	public static void SetMouseDoubleClickCommand(DependencyObject o, ICommand value)
	{
		o.SetValue(MouseDoubleClickCommand, value);
	}

	public static ICommand GetMouseDoubleClickCommand(DependencyObject o)
	{
		return o.GetValue(MouseDoubleClickCommand) as ICommand;
	}
	#endregion Button
}

The shown example only handle button events, but with slight modification can be used for all WPF controls.

In the View:

<Button Command="{Binding Path=ButtonClickCommand}"
		utilities:ControlEventBehaviour.MouseEnterCommand="{Binding Path=MouseEnter}"
		utilities:ControlEventBehaviour.MouseLeaveCommand="{Binding Path=MouseLeave}"
		utilities:ControlEventBehaviour.MouseDoubleClickCommand="{Binding Path=ButtonDoubleClick}">

And finally in the ViewModel. This is only for MouseEnter, but I'm sure that you get the gist of it :)

private RelayCommand _mouseEnter = null;
public virtual RelayCommand MouseEnter
{
	get
	{
		if (_mouseEnter == null)
		{
			_mouseEnter = new RelayCommand(param =>
			{
				try
				{
				}
				catch { }
			}, param => { return true; });
		}
		return _mouseEnter;
	}
}

As always, feel free to comment, or ask.

 It took me some time to find a solution to this problem, but here is a working solution.

 I wanted to be able to drag 'n drop WPF DataGrid rows in MVVM, and although this solution is not strickly MVVM, I still think that it fits nicely in that design patten. All GUI it handled within the view, and all logic in the ViewModel.

 I found a good starting point for this solution somewhere, but again unfortunately I have forgotten where. I think it was on codeproject. My sincere apologies to the author.

 The follwing goes into the UserControl code behind:

using Baltz.ViewModel;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace Baltz.View
{
    /// <summary>
    /// Interaction logic for DataGridDraggableRowView.xaml
    /// </summary>
    public partial class DataGridDraggableRowView : UserControl
    {
        public DataGridDraggableRowView()
        {
            InitializeComponent();
        }

        #region Static Methods
        private static T FindVisualParent<T>(UIElement element) where T : UIElement
        {
            var parent = element;
            while (parent != null)
            {
                var correctlyTyped = parent as T;
                if (correctlyTyped != null)
                {
                    return correctlyTyped;
                }

                parent = VisualTreeHelper.GetParent(parent) as UIElement;
            }
            return null;
        }
        #endregion

        #region Fields
        private int _originalIndex;
        private DataGridRow _oldRow;
        private DataGridDraggableRowItem _targetItem;
        private DataGridDraggableRowViewModel _viewModel;
        #endregion Fields

        #region Event Handlers
        /// <summary>
        /// Updates the grid as a drag progresses
        /// </summary>
        private void OnMainGridCheckDropTarget(object sender, DragEventArgs e)
        {
            var row = FindVisualParent<DataGridRow>(e.OriginalSource as UIElement);

            // Set the DragDropEffects 
            if ((row == null) || !(row.Item is DataGridDraggableRowItem))
            {
                e.Effects = DragDropEffects.None;
            }
            else
            {
                var currentIndex = row.GetIndex();

                // Erase old drop-line
                if (_oldRow != null)
                    _oldRow.BorderThickness = new Thickness(0);

                // Draw new drop-line
                var direction = (currentIndex - _originalIndex);
                if (direction < 0)
                    row.BorderThickness = new Thickness(0, 2, 0, 0);
                else if (direction > 0)
                    row.BorderThickness = new Thickness(0, 0, 0, 2);
                row.BorderBrush = new SolidColorBrush(Color.FromArgb(0xFF, 0x00, 0x9C, 0xDD));
                // Reset old row
                _oldRow = row;
            }
        }

        /// <summary>
        /// Gets the view model from the data Context and assigns it to a member variable.
        /// </summary>
        private void OnMainGridDataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
        {
            _viewModel = (DataGridDraggableRowViewModel)this.DataContext;
        }

        /// <summary>
        /// Process a row drop on the DataGrid.
        /// </summary>
        private void OnMainGridDrop(object sender, DragEventArgs e)
        {
            e.Effects = DragDropEffects.None;
            e.Handled = true;

            // Verify that this is a valid drop and then store the drop target
            var row = FindVisualParent<DataGridRow>(e.OriginalSource as UIElement);
            if (row != null)
            {
                _targetItem = row.Item as DataGridDraggableRowItem;
                if (_targetItem != null)
                {
                    e.Effects = DragDropEffects.Move;
                }
            }

            // Erase last drop-line
            if (_oldRow != null)
                _oldRow.BorderThickness = new Thickness(0, 0, 0, 0);
        }

        /// <summary>
        /// Processes a drag in the main grid.
        /// </summary>
        private void OnMainGridMouseMove(object sender, MouseEventArgs e)
        {
            // Exit if left mouse button aren't pressed
            if (e.LeftButton != MouseButtonState.Pressed)
                return;

            // Find the row the mouse button was pressed on
            var row = FindVisualParent<DataGridRow>(e.OriginalSource as FrameworkElement);
            _originalIndex = row.GetIndex();

            // If the row was already selected, begin drag
            if ((row != null) && row.IsSelected)
            {
                // Get the grocery item represented by the selected row
                var selectedItem = (DataGridDraggableRowItem)row.Item;
                var finalDropEffect = DragDrop.DoDragDrop(row, selectedItem, DragDropEffects.Move);
                if ((finalDropEffect == DragDropEffects.Move) && (_targetItem != null))
                {
                    /* A drop was accepted. Determine the index of the item being 
                     * dragged and the drop location. If they are different, then 
                     * move the selectedItem to the new location. */

                    // Move the dragged item to its drop position
                    var oldIndex = _viewModel.Rows.IndexOf(selectedItem);
                    var newIndex = _viewModel.Rows.IndexOf(_targetItem);
                    if (oldIndex != newIndex)
                        _viewModel.Rows.Move(oldIndex, newIndex);
                    _targetItem = null;
                }
            }
        }
        #endregion
    }
}

A side note: This style is based on a style posted in another post

<ResourceDictionary x:Class="Ellab.Main.Settings.SettingsWindow.View.Styles.DraggableDataGridStyle"
                    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
                    mc:Ignorable="d">
    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="DataGridStyle.xaml"/>
    </ResourceDictionary.MergedDictionaries>
    <Style x:Key="DefaultDraggableDataGrid" BasedOn="{StaticResource DefaultSettingsDataGrid}" TargetType="{x:Type DataGrid}">
        <Setter Property="HeadersVisibility" Value="Column"/>
        <Setter Property="AllowDrop" Value="True"/>
    </Style>
    <Style TargetType="{x:Type DataGridCell}">
        <Style.Resources>
            <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="#FF009CDD" />
            <SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="#FF009CDD" />
            <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Black" />
            <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Black" />
        </Style.Resources>
    </Style>
</ResourceDictionary>

And this is the complete View - most of it isn't relevant for the dragable rows.

<UserControl x:Class="foo.View.barDataGridDraggableRowView"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300">
    <UserControl.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="Styles/DraggableDataGridStyle.xaml"/>
                <ResourceDictionary Source="Styles/ContentPresenterStyle.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </UserControl.Resources>
    <StackPanel Orientation="Vertical" Background="Transparent">
        <ContentPresenter Content="{Binding Path=HeaderButton}" Style="{StaticResource DefaultContentPresenter}"/>
        <StackPanel Orientation="Vertical" Background="Transparent" Visibility="{Binding Path=IsExpanded}">
            <DataGrid ItemsSource="{Binding Path=Rows}"
                  MouseMove="OnMainGridMouseMove"
                  DragEnter="OnMainGridCheckDropTarget"
                  DragLeave="OnMainGridCheckDropTarget"
                  DragOver="OnMainGridCheckDropTarget"
                  Drop="OnMainGridDrop" 
                  DataContextChanged="OnMainGridDataContextChanged"
                  Style="{StaticResource DefaultDraggableDataGrid}">
                <DataGrid.Columns>
                    <DataGridTemplateColumn IsReadOnly="True" Width="20">
                        <DataGridTemplateColumn.CellTemplate>
                            <DataTemplate>
                                <Image Source="../../Resources/DragDrop.png" Stretch="Fill" Opacity="{Binding Opacity}"/>
                            </DataTemplate>
                        </DataGridTemplateColumn.CellTemplate>
                    </DataGridTemplateColumn>
                    <DataGridTemplateColumn IsReadOnly="True">
                        <DataGridTemplateColumn.Header>
                            <TextBlock Text="{Binding DataContext.EnabledColumnHeader, RelativeSource={RelativeSource AncestorType=DataGrid}}" MaxWidth="65" TextWrapping="WrapWithOverflow" TextTrimming="CharacterEllipsis">
                                <TextBlock.LayoutTransform>
                                    <TransformGroup>
                                        <RotateTransform Angle="90" />
                                        <ScaleTransform ScaleX="-1" ScaleY="-1"/>
                                    </TransformGroup>
                                </TextBlock.LayoutTransform>
                            </TextBlock>
                        </DataGridTemplateColumn.Header>
                        <DataGridTemplateColumn.CellTemplate>
                            <DataTemplate>
                                <CheckBox HorizontalAlignment="Center" VerticalAlignment="Center" IsChecked="{Binding EnabledChecked, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" Opacity="{Binding Opacity}" IsEnabled="{Binding Enable}"/>
                            </DataTemplate>
                        </DataGridTemplateColumn.CellTemplate>
                    </DataGridTemplateColumn>
                    <DataGridTemplateColumn IsReadOnly="True">
                        <DataGridTemplateColumn.Header>
                            <TextBlock Text="{Binding DataContext.WizardColumnHeader, RelativeSource={RelativeSource AncestorType=DataGrid}}" MaxWidth="65" TextWrapping="WrapWithOverflow" TextTrimming="CharacterEllipsis">
                                <TextBlock.LayoutTransform>
                                    <TransformGroup>
                                        <RotateTransform Angle="90" />
                                        <ScaleTransform ScaleX="-1" ScaleY="-1"/>
                                    </TransformGroup>
                                </TextBlock.LayoutTransform>
                            </TextBlock>
                        </DataGridTemplateColumn.Header>
                        <DataGridTemplateColumn.CellTemplate>
                            <DataTemplate>
                                <CheckBox HorizontalAlignment="Center" VerticalAlignment="Center" IsChecked="{Binding WizardChecked, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" Opacity="{Binding Opacity}" IsEnabled="{Binding Enable}" Visibility="{Binding WizardVisible}"/>
                            </DataTemplate>
                        </DataGridTemplateColumn.CellTemplate>
                    </DataGridTemplateColumn>
                    <DataGridTemplateColumn IsReadOnly="True" Width="*">
                        <DataGridTemplateColumn.Header>
                            <TextBlock Text="{Binding DataContext.TextColumnHeader, RelativeSource={RelativeSource AncestorType=DataGrid}}" TextWrapping="WrapWithOverflow" TextTrimming="CharacterEllipsis" VerticalAlignment="Bottom"/>
                        </DataGridTemplateColumn.Header>
                        <DataGridTemplateColumn.CellTemplate>
                            <DataTemplate>
                                <TextBlock Text="{Binding Text}" HorizontalAlignment="Left" VerticalAlignment="Center" Opacity="{Binding Opacity}" IsEnabled="{Binding Enable}"/>
                            </DataTemplate>
                        </DataGridTemplateColumn.CellTemplate>
                    </DataGridTemplateColumn>
                    <DataGridTemplateColumn IsReadOnly="True" Width="40">
                        <DataGridTemplateColumn.CellTemplate>
                            <DataTemplate>
                                <Image Source="{Binding TileImage}" Opacity="{Binding Opacity}"/>
                            </DataTemplate>
                        </DataGridTemplateColumn.CellTemplate>
                    </DataGridTemplateColumn>
                </DataGrid.Columns>
            </DataGrid>
            <ContentPresenter Content="{Binding Path=TilesRemainingText}"/>
        </StackPanel>
    </StackPanel>
</UserControl>

As always, feel free to comment, or ask.

Here follows a couple of styles. All used with, but most not limited to, a MVVM desig patten.

First a text style

<ResourceDictionary x:Class="foo.View.Styles.TextStyle"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008">
    <Style x:Key="DefaultTextStyle" TargetType="{x:Type TextBlock}">
        <Setter Property="Background" Value="Transparent"/>
        <Setter Property="VerticalAlignment" Value="Center"/>
        <Setter Property="HorizontalAlignment" Value="Stretch"/>
        <Setter Property="FontSize" Value="12"/>
        <Setter Property="FontWeight" Value="Bold"/>
        <Setter Property="FontFamily" Value="Verdana"/>
        <Setter Property="Foreground" Value="#FF17447E"/>
        <Setter Property="TextWrapping" Value="Wrap"/>
        <Setter Property="TextAlignment" Value="Left"/>
    </Style>
</ResourceDictionary>

Here is a style for a image that will fade in i half a second, and after 1,5 second it will fade out in 1 second

<ResourceDictionary x:Class="foo.View.Styles.FadeOutImageStyle"
                    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
                    mc:Ignorable="d">
    <Style x:Key="DefaultFadeImageStyle" TargetType="{x:Type Image}">
        <Style.Triggers>
            <Trigger Property="IsVisible" Value="True">
                <Trigger.EnterActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <DoubleAnimation Storyboard.TargetProperty="Opacity" From="0.5" To="1.0" BeginTime="0:0:0" Duration="0:0:0.5"/>
                            <DoubleAnimation Storyboard.TargetProperty="Opacity" From="1.0" To="0.0" BeginTime="0:0:1.5" Duration="0:0:1"/>
                        </Storyboard>
                    </BeginStoryboard>
                </Trigger.EnterActions>
            </Trigger>
        </Style.Triggers>
    </Style>
</ResourceDictionary>

and of course can be used like

Style="{StaticResource DefaultFadeOutImageStyle}

Then a style for a plain squre ProgressBar without any glossy effects or gradient colors. This one I found here:

http://stackoverflow.com/questions/12871978/removing-gloss-from-progressbar

<ResourceDictionary x:Class="foo.View.Styles.ProgressBarStyle"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008">
    <Style x:Key="DefaultProgressBar" TargetType="{x:Type ProgressBar}">
        <Setter Property="Background" Value="Transparent"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="ProgressBar">
                    <Border BorderBrush="Transparent" BorderThickness="0" Background="Transparent" CornerRadius="0" Padding="0">
                        <Grid x:Name="PART_Track">
                            <Rectangle x:Name="PART_Indicator" HorizontalAlignment="Left" Fill="#00DB69"/>
                        </Grid>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>

Here is a style for WPF ToolTip that will look something like this:

<ResourceDictionary x:Class="foo.View.Styles.ToolTipStyles"
                    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
                    mc:Ignorable="d">
    <Style x:Key="{x:Type ToolTip}" TargetType="ToolTip">
        <Setter Property="MinHeight" Value="100"/>
        <Setter Property="Placement" Value="Right"/>
        <Setter Property="HasDropShadow" Value="False"/>
        <Setter Property="Visibility" Value="{Binding Path=ToolTipVisible}"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="ToolTip">
                    <Border BorderBrush="White" BorderThickness="4" Width="190" Height="{Binding Path=Height}" Background="{Binding Path=ToolTipBackgroundColor}" MinHeight="100">
                        <DockPanel VerticalAlignment="Top">
                            <TextBlock DockPanel.Dock="Top" 
                                       Text="{Binding Path=DescriptiveText}" 
                                       Visibility="{Binding Path=DescriptiveTextVisibleInToolTip}"
                                       FontSize="14" 
                                       FontWeight="Bold" 
                                       FontFamily="Verdana" 
                                       Foreground="White" 
                                       Margin="5" 
                                       TextWrapping="Wrap" 
                                       TextAlignment="Justify">
                                <TextBlock.Style>
                                    <Style TargetType="TextBlock">
                                        <Style.Triggers>
                                            <Trigger Property="Text" Value="{x:Null}">
                                                <Setter Property="Visibility" Value="Collapsed"/>
                                            </Trigger>
                                            <Trigger Property="Text" Value="">
                                                <Setter Property="Visibility" Value="Collapsed"/>
                                            </Trigger>
                                        </Style.Triggers>
                                    </Style>
                                </TextBlock.Style>
                            </TextBlock>
                            <TextBlock DockPanel.Dock="Top" Text="{Binding Path=ToolTip}" FontSize="10" FontWeight="Bold" FontFamily="Verdana" Foreground="White" Margin="5,0,5,0" TextWrapping="Wrap" TextAlignment="Justify"/>
                            <TextBlock/>
                        </DockPanel>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
        <Style.Triggers>
            <EventTrigger RoutedEvent="ToolTip.Opened">
                <BeginStoryboard>
                    <Storyboard>
                        <DoubleAnimation Storyboard.TargetProperty="Width" From="0.0" To="200" Duration="0:0:.5"/>
                        <DoubleAnimation Storyboard.TargetProperty="Opacity" From="0.0" To="1.0" Duration="0:0:1"/>
                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger>
        </Style.Triggers>
    </Style>
</ResourceDictionary>

A DataGrid style that wiil make the DataGrid look like this:

<ResourceDictionary x:Class="foo.View.Styles.DataGridStyles"
                    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
                    mc:Ignorable="d">
    <Style x:Key="DefaultSettingsDataGrid" TargetType="{x:Type DataGrid}">
        <Setter Property="IsEnabled" Value="{Binding Enable}"/>
        <Setter Property="Width" Value="{Binding DataGridWidth}"/>
        <Setter Property="HorizontalAlignment" Value="Left"/>
        <Setter Property="AlternatingRowBackground" Value="Beige"/>
        <Setter Property="AlternationCount" Value="2"/>
        <Setter Property="CanUserAddRows" Value="False"/>
        <Setter Property="CanUserDeleteRows" Value="False"/>
        <Setter Property="CanUserReorderColumns" Value="False"/>
        <Setter Property="CanUserResizeColumns" Value="False"/>
        <Setter Property="CanUserResizeRows" Value="False"/>
        <Setter Property="CanUserSortColumns" Value="False"/>
        <Setter Property="AutoGenerateColumns" Value="False"/>
        <Setter Property="HeadersVisibility" Value="None"/>
        <Setter Property="VerticalAlignment" Value="Center"/>
        <Setter Property="TextBlock.FontFamily" Value="Calibri"/>
        <Setter Property="TextBlock.FontSize" Value="14"/>
        <Setter Property="TextBlock.FontWeight" Value="Bold"/>
        <Setter Property="TextBlock.Foreground" Value="Black"/>
        <Setter Property="TextBlock.TextWrapping" Value="Wrap"/>
        <Setter Property="TextBlock.VerticalAlignment" Value="Center"/>
        <Setter Property="GridLinesVisibility" Value="None"/>
        <Setter Property="BorderBrush" Value="#FF009CDD"/>
        <Setter Property="BorderThickness" Value="3"/>
        <Style.Resources>
            <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="Transparent" />
            <SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Transparent" />
            <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Black" />
            <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Black" />
        </Style.Resources>
        <Style.Triggers>
            <Trigger Property="IsVisible" Value="True">
                <Trigger.EnterActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <DoubleAnimation Storyboard.TargetProperty="Opacity" From="0.0" To="1.0" Duration="0:0:0.8"/>
                        </Storyboard>
                    </BeginStoryboard>
                </Trigger.EnterActions>
            </Trigger>
        </Style.Triggers>
    </Style>
</ResourceDictionary>

 A ComboBox, that look like this:

<ResourceDictionary x:Class="foo.View.Styles.FlatComboBoxStyles"
                    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
                    mc:Ignorable="d">
    <Style x:Key="FlatComboBox" TargetType="{x:Type ComboBox}">
        <Setter Property="HorizontalAlignment" Value="Stretch"/>
        <Setter Property="HorizontalContentAlignment" Value="Right"/>
        <Setter Property="VerticalAlignment" Value="Top"/>
        <Setter Property="MinWidth" Value="100"/>
        <Setter Property="UIElement.SnapsToDevicePixels" Value="True"/>
        <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled"/>
        <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
        <Setter Property="ScrollViewer.CanContentScroll" Value="True"/>
        <Setter Property="TextElement.Foreground" Value="Black"/>
        <Setter Property="FrameworkElement.FocusVisualStyle" Value="{x:Null}"/>
        <Setter Property="BorderBrush" Value="Transparent"/>
        <Setter Property="BorderThickness" Value="0"/>
        <Setter Property="Background" Value="Transparent" />
    </Style>
</ResourceDictionary>

Now this is a bit more complex. I don't know if it could be done more elegantly.

Obvious I found this style somewhere, but unfortunately I’ve forgotten where. Sincere apologies to the author.

Here is what the vertical ScrollBar that will look like this:

This style is only for a vertical ScrollBar:

<ResourceDictionary x:Class="foo.View.Styles.ScrollViewerStyle"
                    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
                    mc:Ignorable="d">
    <Style x:Key="DefaultScrollViewer" TargetType="{x:Type ScrollViewer}">
        <Setter Property="VerticalScrollBarVisibility" Value="Auto"/>
        <Setter Property="HorizontalScrollBarVisibility" Value="Hidden"/>
        <Setter Property="Background" Value="Transparent"/>
    </Style>

    <!-- SrollViewer ScrollBar Repeat Buttons (at each end) -->
    <Style x:Key="ScrollBarLineButton" TargetType="{x:Type RepeatButton}">
        <Setter Property="SnapsToDevicePixels" Value="True"/>
        <Setter Property="OverridesDefaultStyle" Value="true"/>
        <Setter Property="Focusable" Value="false"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type RepeatButton}">
                    <Border Name="Border" Margin="0" CornerRadius="0" Background="#FF009CDD" BorderThickness="1" BorderBrush="White">
                        <Path HorizontalAlignment="Center" VerticalAlignment="Center" Fill="#FF009CDD" Data="{Binding Path=Content, RelativeSource={RelativeSource TemplatedParent}}" />
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsPressed" Value="true">
                            <Setter TargetName="Border" Property="Background" Value="#FF009CDD" />
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Foreground" Value="Gray"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <!-- SrollViewer ScrollBar Repeat Buttons (The part in the middle, not the thumb the long area between the buttons ) -->
    <Style x:Key="ScrollBarPageButton" TargetType="{x:Type RepeatButton}">
        <Setter Property="SnapsToDevicePixels" Value="True"/>
        <Setter Property="OverridesDefaultStyle" Value="true"/>
        <Setter Property="IsTabStop" Value="false"/>
        <Setter Property="Focusable" Value="false"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type RepeatButton}">
                    <Border Background="Transparent" />
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <!-- ScrollViewer ScrollBar Thumb, that part that can be dragged up/down or left/right Buttons -->
    <Style x:Key="ScrollBarThumb" TargetType="{x:Type Thumb}">
        <Setter Property="SnapsToDevicePixels" Value="True"/>
        <Setter Property="OverridesDefaultStyle" Value="true"/>
        <Setter Property="IsTabStop" Value="false"/>
        <Setter Property="Focusable" Value="false"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type Thumb}">
                    <Border CornerRadius="0" Background="{TemplateBinding Background}" BorderThickness="1" BorderBrush="White"/>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

    <ControlTemplate x:Key="VerticalScrollBar" TargetType="{x:Type ScrollBar}">
        <Grid >
            <Grid.RowDefinitions>
                <RowDefinition MaxHeight="18"/>
                <RowDefinition Height="0.00001*"/>
                <RowDefinition MaxHeight="18"/>
            </Grid.RowDefinitions>
            <Border Grid.RowSpan="3" CornerRadius="0" Background="White" />
            <RepeatButton Grid.Row="0" Style="{StaticResource ScrollBarLineButton}" Height="18" Command="ScrollBar.LineUpCommand" Content="M 0 4 L 8 4 L 4 0 Z" />
            <Track Name="PART_Track" Grid.Row="1" IsDirectionReversed="true">
                <Track.DecreaseRepeatButton>
                    <RepeatButton Style="{StaticResource ScrollBarPageButton}" Command="ScrollBar.PageUpCommand" />
                </Track.DecreaseRepeatButton>
                <Track.Thumb>
                    <Thumb Style="{StaticResource ScrollBarThumb}" Margin="0,0,0,0" Background="#FF009CDD"/>
                </Track.Thumb>
                <Track.IncreaseRepeatButton>
                    <RepeatButton Style="{StaticResource ScrollBarPageButton}" Command="ScrollBar.PageDownCommand" />
                </Track.IncreaseRepeatButton>
            </Track>
            <RepeatButton Grid.Row="3" Style="{StaticResource ScrollBarLineButton}" Height="18" Command="ScrollBar.LineDownCommand" Content="M 0 0 L 4 4 L 8 0 Z"/>
        </Grid>
    </ControlTemplate>
    <!-- Style for overall  ScrollBar -->
    <Style x:Key="{x:Type ScrollBar}" TargetType="{x:Type ScrollBar}">
        <Setter Property="SnapsToDevicePixels" Value="True"/>
        <Setter Property="OverridesDefaultStyle" Value="true"/>
        <Style.Triggers>
            <Trigger Property="Orientation" Value="Vertical">
                <Setter Property="Width" Value="18"/>
                <Setter Property="Height" Value="Auto" />
                <Setter Property="Template"
                        Value="{StaticResource VerticalScrollBar}" />
            </Trigger>
        </Style.Triggers>
    </Style>

    <!-- Style for overall  ScrollViewer -->
    <Style x:Key="FavsScrollViewer" TargetType="{x:Type ScrollViewer}">
        <Setter Property="OverridesDefaultStyle" Value="True"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ScrollViewer}">
                    <Grid>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="Auto"/>
                            <ColumnDefinition/>
                        </Grid.ColumnDefinitions>
                        <Grid.RowDefinitions>
                            <RowDefinition/>
                            <RowDefinition Height="Auto"/>
                        </Grid.RowDefinitions>
                        <ScrollContentPresenter Grid.Column="1"/>
                        <ScrollBar Name="PART_VerticalScrollBar" Value="{TemplateBinding VerticalOffset}" Maximum="{TemplateBinding ScrollableHeight}" ViewportSize="{TemplateBinding ViewportHeight}" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}"/>
                        <ScrollBar Name="PART_HorizontalScrollBar" Orientation="Horizontal" Grid.Row="1" Grid.Column="1" Value="{TemplateBinding HorizontalOffset}" Maximum="{TemplateBinding ScrollableWidth}" ViewportSize="{TemplateBinding ViewportWidth}" Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}"/>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>

And a style for a plain button, looking like this:

<ResourceDictionary x:Class="Ellab.WPF.View.Styles.ButtonStyle" 
                    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" >
    <Style x:Key="DefaultButtonStyle" TargetType="{x:Type Button}">
        <Setter Property="BorderThickness" Value="0"/>
        <Setter Property="Background" Value="#FF009CDD"/>
        <Setter Property="TextElement.FontSize" Value="14"/>
        <Setter Property="TextElement.FontWeight" Value="Bold"/>
        <Setter Property="TextElement.FontFamily" Value="Calibri"/>
        <Setter Property="TextElement.Foreground" Value="White"/>
        <Style.Triggers>
            <Trigger Property="IsMouseOver" Value="True">
                <Setter Property="BorderBrush" Value="#FF123F74"/>
                <Setter Property="BorderThickness" Value="2"/>
            </Trigger>
            <Trigger Property="IsMouseOver" Value="False">
                <Setter Property="BorderThickness" Value="0"/>
            </Trigger>
            <Trigger Property="IsDefault" Value="True">
                <Setter Property="BorderBrush" Value="#FF123F74"/>
                <Setter Property="BorderThickness" Value="2"/>
            </Trigger>
        </Style.Triggers>
    </Style>
</ResourceDictionary>

As always, feel free to comment, or ask.

An example of a ‘ViewModelBase’ class, that implements INotifyPropertyChanged.

public abstract class ViewModelBase : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
    protected virtual bool SetProperty<T>(ref T storage, T value, [CallerMemberName] string propertyName = "")
    {
        if (EqualityComparer<T>.Default.Equals(storage, value))
            return false;
        storage = value;
        this.OnPropertyChanged(propertyName);
        return true;
    }
}

And use it like this:

private string _totalTime;
public string TotalTime
{
    get { return _totalTime; }
    set
    {
        if (_totalTime != value)
        {
            _totalTime = value;
            OnPropertyChanged();
        }
    }
}

... or even:

private string _totalTime;
public string TotalTime
{
    get { return _totalTime; }
    set { SetProperty(ref _totalTime, value); }
}

As always, feel free to comment, or ask.

OK - a quick WPF/XAML/MVVM post. Mostly for my own benefit, so I can remember the syntax. This one about a MVVM resource file.

<ResourceDictionary x:Class="FooBar.MVVMResources"
                    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
                    xmlns:vm="clr-namespace:foo.ViewModel"
                    xmlns:vw="clr-namespace:foo.View"
                    xmlns:vm_common="clr-namespace:bar.ViewModel;assembly=BarAssembly"
                    xmlns:vw_common="clr-namespace:bar.View;assembly=BarAssembly">

    <DataTemplate DataType="{x:Type vm:fooViewModel}">
        <vw:fooView/>
    </DataTemplate>

    <DataTemplate DataType="{x:Type vm_common:barViewModel}">
        <vw_common:barView/>
    </DataTemplate>
</ResourceDictionary>

As always, feel free to comment, or ask.