#462 – Drawing a Better Looking GridSplitter

By default, a GridSplitter control is composed only of a Border element.  You can set the border’s thickness, color and background.

We can make the GridSplitter look a little nicer by drawing a couple horizontal lines on its surface.

We do this by overriding the default Style for the GridSplitter.

	<Window.Resources>
		<Style x:Key="GridSplitterPreviewStyle" >
			<Setter Property="Control.Template">
				<Setter.Value>
					<ControlTemplate>
						<Rectangle Fill="#80000000"/>
					</ControlTemplate>
				</Setter.Value>
			</Setter>
		</Style>
		<Style x:Key="GridSplitterStyle1" TargetType="{x:Type GridSplitter}">
			<Setter Property="Background"
                    Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
			<Setter Property="PreviewStyle" Value="{StaticResource GridSplitterPreviewStyle}"/>
			<Setter Property="Template">
				<Setter.Value>
					<ControlTemplate TargetType="{x:Type GridSplitter}">
						<Border BorderBrush="{TemplateBinding BorderBrush}"
                                BorderThickness="{TemplateBinding BorderThickness}"
                                Background="{TemplateBinding Background}"
                                CornerRadius="5">
                            <Canvas RenderOptions.EdgeMode="Aliased" UseLayoutRounding="True"
                                    Height="6" VerticalAlignment="Center"
                                    Width="50" HorizontalAlignment="Center">
                                <Line X1="0" X2="50" Y1="0" Y2="0"
                                      Stroke="White" StrokeThickness="1"/>
                                <Line X1="0" X2="50" Y1="1" Y2="1"
                                      Stroke="#A0A0A0" StrokeThickness="1"/>
                                <Line X1="0" X2="50" Y1="4" Y2="4"
                                      Stroke="White" StrokeThickness="1"/>
                                <Line X1="0" X2="50" Y1="5" Y2="5"
                                      Stroke="#A0A0A0" StrokeThickness="1"/>
                            </Canvas>
						</Border>
					</ControlTemplate>
				</Setter.Value>
			</Setter>
		</Style>
	</Window.Resources>

We also specify a gradient fill for the Background of the GridSplitter.

    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition Height="Auto"/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition/>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>

        <Label Content="Row 0 Col 0" Background="Azure" Grid.Row="0" Grid.Column="0" />
        <Label Content="Row 0 Col 1" Background="Lavender" Grid.Row="0" Grid.Column="1" />
        <Label Content="Row 2 Col 0" Background="Moccasin" Grid.Row="2" Grid.Column="0" />
        <Label Content="Row 2 Col 1" Background="Honeydew" Grid.Row="2" Grid.Column="1" />

        <GridSplitter Grid.Row ="1" Grid.ColumnSpan="2" Height="16"
                      VerticalAlignment="Center" HorizontalAlignment="Stretch"
                      BorderBrush="White" BorderThickness="1"
					  Style="{DynamicResource GridSplitterStyle1}">
            <GridSplitter.Background>
                <LinearGradientBrush EndPoint="0.5,0" StartPoint="0.5,1">
                    <GradientStop Color="#A0A0A0" Offset="0"/>
                    <GradientStop Color="#E5E5E5" Offset="0.15"/>
                    <GradientStop Color="#ECECEC" Offset="0.8"/>
                    <GradientStop Color="#E5E5E5" Offset="1"/>
                </LinearGradientBrush>
            </GridSplitter.Background>
        </GridSplitter>
    </Grid>