WPF TabItem not highlighted it should

Question

I have three tabs. By simply being clicked individually, they will be highlighted individually as they should.

There are RelyCommand behind these tabs. Whenever the mune is clicked, the program should bring back the first TabItem and it should be highlighted. However, when the second tab is clicked, the first tab would not be highlighted as it should, although it behaves like it does get clicked. It is just not highlighted.

Here is the code behind

xaml code for the two tabs at View level:

<StackPanel Orientation="Horizontal"
                        Background="{x:Null}">
                <TabControl Height="50" Margin="12,0,0,0">
                    <TabItem Name="tiCaptureSetup" IsSelected="{Binding Path=IsCaptureSetupTabSelected, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}">
                        <TabItem.Header>                            
                            <Button Name="btnCaptureSetup"
                                    Grid.Column="0"
                                    Width="90"
                                    Height="40"
                                    Margin="5"
                                    ToolTip="Capture Setup"
                                    Content="Capture Setup"
                                    Click="btnCaptureSetup_Click"
                                    IsEnabled="{Binding Path=CaptureSetupButtonStatus, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}"
                                    IsDefault="True"
                                    ></Button>
                        </TabItem.Header>
                    </TabItem>
                    <TabItem Name="tiCapture" IsSelected="{Binding Path=IsCaptureTabSelected, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}">
                        <TabItem.Header>
                            <Button Name="btnCapture"
                                    Grid.Column="0"
                                    Margin="5"
                                    Width="90"
                                    Height="40"
                                    ToolTip="Capture"
                                    Content="Capture"
                                    Click="btnCapture_Click"
                                    IsEnabled="{Binding Path=CaptureButtonStatus, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}"></Button>
                        </TabItem.Header>
                    </TabItem>

The C# code at ViewModel level (CaptureSetup() is the RelyCommand for clicking the first tab, and HardwareSetupLS() is the RelyCommand for the pop-up window on the menu, and RefereshCaptureSetup() is basically trying to retrieve the first tab when the menu window pops up)

  public void CaptureSetup()
        {
            Command command = new Command();
            command.Message = "Capture Setup";
            command.CommandGUID = new Guid("6ecb028e-754e-4b50-b0ef-df8f344b668e");

            _eventAggregator.GetEvent<CommandShowDialogEvent>().Publish(command);
        }

        public void HardwareSetupLS()
        {
            //RefereshCaptureSetup(); // refresh panel when hardware setting window is loaded.

            Command command = new Command();
            command.Message = "HardwareSetupLS";
            command.CommandGUID = new Guid("64c695e6-8959-496c-91f7-5a9a95d91e0d");

            _eventAggregator.GetEvent<CommandShowDialogEvent>().Publish(command);
            RefereshCaptureSetup();
        }

        public void RefereshCaptureSetup()  // refresh CaptureSetup UI 
        {
            _isCaptureSetupTabSelected = true;
            _isCaptureTabSelected = false;
            _isReviewTabSelected = false;
            Command command = new Command();
            command.Message = "Capture Setup";
            command.CommandGUID = new Guid("{6ecb028e-754e-4b50-b0ef-df8f344b668e}");

            _eventAggregator.GetEvent<CommandShowDialogEvent>().Publish(command);
        }

I am very confused at this point what else I can do to make the first TabItem highlighted as it should.

Answer 1

I feel like there is some important logic missing in your question (e.g. how the IsCaptureSetupTabSelected and IsCaptureTabSelected are updated) but anyway here are three pointers from looking at your code:

• UpdateSourceTrigger=PropertyChanged is useless since your bindings are OneWay (from the source in your ViewModel towards your UI, the source is never updated). If you have written some logic expected to receive IsSelected change notification upon mouse clicks, this won't happen.

• You seem to be updating the inner properties wrapped by your bound properties (e.g. _isCaptureSetupTabSelected = true instead of IsCaptureSetupTabSelected = true ) and thus, could be missing the proper INotifyPropertyChanged event that the UI is expecting.

• Make sure that the proper TabItem is on focus.