WPF Events in ResourceDictionary for a ControlTemplate - wpf

Question

I'm currently trying to implement a Metro styled Window.
So i've made the following styles inside a ResourceDictionary:
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<!-- Brushes -->
<SolidColorBrush x:Key="BackgroundColor" Color="#FFFFFFFF" />
<!-- Buttons -->
<Style x:Key="MetroControlBoxButton" TargetType="Button">
<Setter Property="Background" Value="{StaticResource BackgroundColor}" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<ContentPresenter />
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<!-- Windows -->
<Style x:Key="MetroWindow" TargetType="Window">
<Setter Property="UseLayoutRounding" Value="True" />
<Setter Property="WindowStyle" Value="None" />
<Setter Property="ResizeMode" Value="NoResize" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Window">
<Grid Background="{StaticResource BackgroundColor}">
<Grid.RowDefinitions>
<RowDefinition Height="6" />
<RowDefinition Height="24" />
<RowDefinition Height="*" />
<RowDefinition Height="24" />
<RowDefinition Height="6" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="6" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="6" />
</Grid.ColumnDefinitions>
<Rectangle Name="topLeftBorderRectangle" Fill="Red" Grid.Row="0" Grid.Column="0" />
<Rectangle Name="topCenterBorderRectangle" Fill="Orange" Grid.Row="0" Grid.Column="1" />
<Rectangle Name="topRightBorderRectangle" Fill="Red" Grid.Row="0" Grid.Column="2" />
<Rectangle Name="middleLeftBorderRectangle" Fill="Orange" Grid.Row="1" Grid.RowSpan="3" Grid.Column="0" />
<Rectangle Name="middleRightBorderRectangle" Fill="Orange" Grid.Row="1" Grid.RowSpan="3" Grid.Column="2" />
<Rectangle Name="bottomLeftBorderRectangle" Fill="Red" Grid.Row="4" Grid.Column="0" />
<Rectangle Name="bottomCenterBorderRectangle" Fill="Orange" Grid.Row="4" Grid.Column="1" />
<Rectangle Name="bottomRightBorderRectangle" Fill="Red" Grid.Row="4" Grid.Column="2" />
<Rectangle Name="statusBarRectangle" Fill="Yellow" Grid.Row="3" Grid.Column="1" />
<Grid Grid.Row="1" Grid.Column="1">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="28" />
<ColumnDefinition Width="28" />
<ColumnDefinition Width="28" />
</Grid.ColumnDefinitions>
<Rectangle Name="dragRectangle" Fill="Yellow" Grid.Row="0" Grid.Column="1" />
<Button Name="minimizeButton" Content="_" Grid.Row="0" Grid.Column="2" Style="{StaticResource MetroControlBoxButton}" Command="{Binding Path=DataContext.MinimizeCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}}" />
<Button Name="maximizeButton" Content="[]" Grid.Row="0" Grid.Column="3" Style="{StaticResource MetroControlBoxButton}" Command="{Binding Path=DataContext.MaximizeNormalizeCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}}" />
<Button Name="closeButton" Content="X" Grid.Row="0" Grid.Column="4" Style="{StaticResource MetroControlBoxButton}" Command="{Binding Path=DataContext.CloseCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}}" />
</Grid>
<ContentPresenter Grid.Row="2" Grid.Column="1" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
My problem is that i have no idea how to implement de drag feature.
My dragRectangle doesn't have a Command property so how can i call DragMove() on MouseLeftButtonDown on a Rectangle using MVVM?
Thanks

Answer 1

A ResourceDictionary can have code behind just like Windows etc. so you could add an event handler and call DragMove from there
Setting up the code behind requires a couple of steps.
If your ResourceDictionary is called MetroStyleResourceDictionary.xaml you add a new file in Visual Studio in the same folder called MetroStyleResourceDictionary.xaml.cs
The code behind file should then look like this
public partial class MetroStyleResourceDictionary
{
//...
}
After that you need to add the x:Class attribute to the Xaml file
<ResourceDictionary x:Class="YourNamespace.MetroStyleResourceDictionary"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<!--...-->
</ResourceDictionary>
Now you can add an event handler to the dragRectangle for MouseLeftButtonDown. You'll also need to get a hold of the Window so binding that to Tag might be a good idea
<Rectangle Name="dragRectangle"
MouseLeftButtonDown="dragRectangle_MouseLeftButtonDown"
Tag="{Binding RelativeSource={RelativeSource AncestorType={x:Type Window}}}"
.../>
And finally you can add the event handler to the code behind file which will look like this
public partial class MetroStyleResourceDictionary
{
void dragRectangle_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
Rectangle dragRectangle = sender as Rectangle;
Window window = dragRectangle.Tag as Window;
if (window != null)
{
window.DragMove();
}
}
}