Customizing Mahapps.MetroWindow Close Button

Question

I'm using Mahapps.MetroWindow ( http://mahapps.com/ ) to style my applications appearance and right now I'm looking for the right way to customize the appearance of the X / Close button. By default MetroWindow applies custom styling to all three command buttons. I would like to either match Windows in always having the Close button be red or on mouse over become red.

What I found so far was, that I can set the WindowCloseButtonStyle attribute to a custom style. I did so like this:

<controls:MetroWindow x:Class="WpfApplication2.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:controls="clr-namespace:MahApps.Metro.Controls;assembly=MahApps.Metro"
    Title="MainWindow" 
    Height="350" 
    Width="525"
    WindowCloseButtonStyle="{DynamicResource RedCloseWindowButtonStyle}">
...

In a separate XAML file I've got the style defined as

<Style x:Key="RedCloseWindowButtonStyle"
       TargetType="{x:Type Button}"
       BasedOn="{StaticResource MetroBaseWindowButtonStyle}">
    <Setter Property="XXX"
               Value="XXX" />
</Style>

I assume that I'll have to fill in the blanks for XXX in the style setter. Since I'm new to Windows development my question is: What's the property I'm interested in? Where can I find an explorer to browse the available properties depending on the given context? and what's the style value if I want to accomplish what I described above?

Answer 1

Here is an inherited custom style for a close button with mouse over / pressed effect:

<Style x:Key="MetroWindowCloseButtonStyle"
       TargetType="{x:Type Button}"
       BasedOn="{StaticResource MetroWindowButtonStyle}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Button}">
                <Grid x:Name="grid"
                      Background="{TemplateBinding Background}">
                    <ContentPresenter x:Name="contentPresenter"
                                      HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                      Margin="{TemplateBinding Padding}"
                                      VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                                      SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
                                      RecognizesAccessKey="True"
                                      Opacity="0.75" />
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver"
                             Value="True">
                        <Setter TargetName="contentPresenter"
                                Property="Opacity"
                                Value="1" />
                        <Setter TargetName="grid"
                                Property="Background"
                                Value="#E04343" />
                    </Trigger>
                    <Trigger Property="IsMouseOver"
                             Value="False">
                        <Setter TargetName="contentPresenter"
                                Property="Opacity"
                                Value=".5" />
                    </Trigger>
                    <Trigger Property="IsPressed"
                             Value="True">
                        <Setter TargetName="grid"
                                Property="Background"
                                Value="#993D3D" />
                    </Trigger>
                    <Trigger Property="IsEnabled"
                             Value="false">
                        <Setter Property="Foreground"
                                Value="#ADADAD" />
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

The original (obsolete) style can be found here on GitHub

Hope that helps.

Answer 2

Well, In the new version of I dont find the style "MetroWindowCloseButtonStyle" I have rewritten the style "MetroBaseWindowButtonStyle" with and extra style trigger: The trigger will fire only if the button name is "PART_Close" which is the default mahapp button name. So it will change the background color to red when hover to close button.

<MultiTrigger>
  <MultiTrigger.Conditions>
    <Condition Property="IsMouseOver" Value="True" />
    <Condition Property="Name" Value="PART_Close" />
  </MultiTrigger.Conditions>

  <Setter Property="Background" Value="Red" />
</MultiTrigger>

The complete style is here:

 <!-- base button style for min, max and close window buttons -->
 <Style x:Key="MetroBaseWindowButtonStyle" TargetType="{x:Type Button}">
    <Setter Property="Background"
            Value="{DynamicResource TransparentWhiteBrush}" />
    <Setter Property="Foreground"
            Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" />
    <Setter Property="HorizontalContentAlignment"
            Value="Center" />
    <Setter Property="VerticalContentAlignment"
            Value="Center" />
    <Setter Property="Padding"
            Value="1" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Button}">
                <Grid Background="{TemplateBinding Background}">
                    <ContentPresenter x:Name="contentPresenter"
                                      HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                      Margin="{TemplateBinding Padding}"
                                      VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                                      SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
                                      RecognizesAccessKey="True"
                                      Opacity="0.75" />
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver"
                             Value="True">
                        <Setter TargetName="contentPresenter"
                                Property="Opacity"
                                Value="1" />
                    </Trigger>
                    <Trigger Property="IsMouseOver"
                             Value="False">
                        <Setter TargetName="contentPresenter"
                                Property="Opacity"
                                Value=".5" />
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
    <Style.Triggers>
        <Trigger Property="IsMouseOver"
                 Value="True">
            <Setter Property="Background"
                    Value="#F6F6F6" />
        </Trigger>
        <Trigger Property="IsPressed"
                 Value="True">
            <Setter Property="Background"
                    Value="{DynamicResource HighlightBrush}" />
        </Trigger>
        <Trigger Property="IsEnabled"
                 Value="false">
            <Setter Property="Foreground"
                    Value="#ADADAD" />
        </Trigger>
        <MultiTrigger>
            <MultiTrigger.Conditions>
                <Condition Property="IsMouseOver"
                           Value="True" />
                <Condition Property="Name"
                           Value="PART_Close" />
            </MultiTrigger.Conditions>
            <Setter Property="Background"
                    Value="Red" />
        </MultiTrigger>
    </Style.Triggers>
  </Style>