How to change the background of tabitem by using trigger in xaml? - wpf

Question

Here is my Xaml code
<Window.Resources>
<Style x:Key="SimpleTabControl" TargetType="{x:Type TabItem}">
<!--<Setter Property = "TabStripPlacement" Value = "Top"/>-->
<Setter Property = "Background" Value= "Gray"/>
<Setter Property="FontSize" Value="15"/>
<Setter Property="Width" Value="200"/>
<Setter Property="Height" Value="40"/>
<Setter Property="HorizontalAlignment" Value="Left"/>
<Setter Property="IsSelected" Value="False"/>
<Setter Property="Margin" Value="3,0"/>
<Style.Triggers>
<Trigger Property="TabItem.IsMouseOver" Value="true">
<Setter Property="Background" Value="LightGreen"></Setter>
</Trigger>
</Style.Triggers>
</Style>
<EventTrigger RoutedEvent="MouseEnter">
<EventTrigger.Actions>
</EventTrigger.Actions>
</EventTrigger>
</Style.Triggers>
</Style>
<Style TargetType="{x:Type TabPanel}">
<Setter Property="Background" Value="LightGreen"></Setter>
</Style>
</Window.Resources>
<Grid Background="White" Height="1000" Width="auto" IsEnabled="True">
<TabControl Name="MainTab" Background="LightGray" SelectionChanged="MainTab_SelectionChanged">
<TabControl.Resources>
<Style TargetType="{x:Type TabPanel}">
<Setter Property="HorizontalAlignment" Value="Left" />
<Setter Property="Background" Value="White"/>
</Style>
</TabControl.Resources>
<TabItem Header="Input" x:Name="tabAlert1" Style="{StaticResource SimpleTabControl}" MouseEnter="TabItem_Enter" MouseLeave="TabItem_Leave" MouseDoubleClick="TabItem_Click" >
<!--<TabItem.Header>
<Border Padding="0,0">
<StackPanel Orientation="Horizontal" Background="Gray" HorizontalAlignment="Left" Width="200" Height="40" Margin="0,0">
<TextBlock Text="Input" Foreground="White" FontSize="15" TextAlignment="Right"/>
</StackPanel>
</Border>
</TabItem.Header>-->
<Label Content="Content goes here..." />
</TabItem>
<TabItem Header="Analysis" x:Name="tabAlert2" Style="{StaticResource SimpleTabControl}" />
<TabItem Header="Action???" x:Name="tabAlert3" Style="{StaticResource SimpleTabControl}"/>
</TabControl>
</Grid>
I don't know for some reason the trigger for isMouseOver is not triggering the back ground color change Change for Tab Item.
I have also tried the c# , code behind way , but with no success, but if change the foreground property, it works, but not he Background property.
Here is my C# Way
private void TabItem_Enter(object sender, System.Windows.Input.MouseEventArgs e)
{
//var tabItem = sender as TabItem;
//tabAlert2.Background = Brushes.Red;
//tabItem.Background = Brushes.Green;
var tabItem = sender as TabItem;
tabItem.Background = new SolidColorBrush(Colors.Gray);
}
I have Bound the mouse enter event to tab Item.this is very basic but am frustrated this not working?Any help much appreciated.

Answer 1

I'm not sure but I think you want to change the color of the Header?
If so, you can change the header template, try this code and if it works for you, add your other properties.
<Window.Resources>
<Style TargetType="TabItem">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="TabItem">
<Grid Name="Panel">
<Border Name="Border" BorderThickness="1,1,1,0" BorderBrush="Gainsboro" CornerRadius="4,4,0,0" Margin="2,0">
<ContentPresenter x:Name="ContentSite"
VerticalAlignment="Center"
HorizontalAlignment="Center"
ContentSource="Header"
Margin="10,2"/>
</Border>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter TargetName="Border" Property="Background" Value="LightGreen"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="False">
<Setter TargetName="Border" Property="Background" Value="White" />
</Trigger>
<Trigger Property="IsSelected" Value="True">
<Setter TargetName="Border" Property="Background" Value="LightBlue"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Grid>
<TabControl Name="MainTab">
<TabItem Header="Input" x:Name="tabAlert1"/>
<TabItem Header="Analysis" x:Name="tabAlert2"/>
<TabItem Header="Action???" x:Name="tabAlert3"/>
</TabControl>
</Grid>
(Mouse is over second tab)