How to remove the auto-focus behaviour after click the header of the selected TabItem?

Question

For illustration, I added 2 TabItems into a TabControl and make the first one selected. After start the app, if I click the Header of this selected TabItem, the TextBox named "txtFocused" will get focus. How to remove this default behaviour? I don't want any control in TabItem focused when click the TabItem. The txtFocused should get focus only when user click on the TextBox itself.

         <TabControl>
            <TabItem Header="123" IsSelected="True">
                <StackPanel>
                    <TextBox x:Name="txtFocused">123</TextBox>
                    <TextBox>123</TextBox>
                </StackPanel>
            </TabItem>
            <TabItem Header="123">
                <StackPanel>
                    <TextBox>223</TextBox>
                    <TextBox>432</TextBox>
                </StackPanel>
            </TabItem>
        </TabControl>

Answer 1

You can add a SelectionChanged event to TabControl , and add using System.Threading; for the class

        private void TabControl_SelectionChanged(object sender, SelectionChangedEventArgs e)  
        {  
            Dispatcher.BeginInvoke((ThreadStart)delegate  
            {  
                Keyboard.ClearFocus();  
            });  
        }      

---

If the response is helpful, please click "Accept Answer" and upvote it.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 2

You can add your TabItem header in a lable then add a click event to it, below is my code demo:
The code for xaml:

  <Window.Resources>  
        <Style TargetType="Label" x:Key="myLable">  
            <Setter Property="Height" Value="25"></Setter>  
            <Setter Property="Width" Value="50"></Setter>  
            <EventSetter Event="PreviewMouseLeftButtonDown" Handler="Label_PreviewMouseLeftButtonDown"></EventSetter>  
        </Style>  
    </Window.Resources>  
    <Grid Name="Mygrid">  
        <TabControl Name="mytab" SelectedIndex="0">  
            <TabItem>  
                <TabItem.Header>  
                    <Label Content="123" Style="{StaticResource myLable}"></Label>  
                </TabItem.Header>  
                <StackPanel>  
                    <TextBox x:Name="txtFocused">123</TextBox>  
                    <TextBox>123</TextBox>  
                </StackPanel>  
            </TabItem>  
            <TabItem >  
                <TabItem.Header>  
                    <Label Content="123" Style="{StaticResource myLable}"></Label>  
                </TabItem.Header>  
                <StackPanel>  
                    <TextBox>223</TextBox>  
                    <TextBox>432</TextBox>  
                </StackPanel>  
            </TabItem>  
        </TabControl>  
    </Grid>  

The code for Label_PreviewMouseLeftButtonDown event is same as TimonYang-MSFT.

---

If the response is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.