将焦点设置为新TabItem中的按钮

Question

I use a TabControl to display a list of items. The ItemView is a separate control I wrote.

       <TabControl SelectedItem="{Binding CurrentItem}"
                    IsSynchronizedWithCurrentItem="True"
                    ItemsSource="{Binding ItemList}">
            <TabControl.ContentTemplate>
                <DataTemplate>
                    <ctrls:ItemView/>
                </DataTemplate>
            </TabControl.ContentTemplate>
            <TabControl.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding ShortItemDescription}"/>
                </DataTemplate>
            </TabControl.ItemTemplate>
        </TabControl>

If the user presses a Button a new ViewModel is added to the list of ViewModels and the TabControl displays it as a new tab. After adding the new tab is selected.

       <Button Command="{Binding AddItemCommand}"
               Content="Add item"/>

Inside of the new View is a button that needs to be focused each time a new tab is added. I have tried to use the FocusManager and the Initialized event in the ItemView but these are only called for the first time I add a new tab.

<UserControl x:Class="ItemView"
         ...
         Initialized="ViewInitialized">
<Grid>
    ...

    <!-- Set focus to this button -->
    <Button Content="Search"
            Command="{Binding SearchCommand}"
            Name="SearchButton"
            Grid.Column="0"
            Grid.Row="0"/>
</Grid>
</UserControl>

Any ideas?

Update

The content of the Initialize method in the ItemView is currently this one - which is working fine... for the first time and then never again

    public delegate void ChangeFocusDelegate();

    private void FocusSearchButton()
    {
        SearchButton.Focus();
    }

    private void ViewInitialized(object sender, EventArgs e)
    {
        ChangeFocusDelegate focusDelegate = FocusSearchButton;
        Dispatcher.BeginInvoke(DispatcherPriority.ContextIdle, focusDelegate);
    }

Answer 1

This should be work like this (over your defined Initialized event of the UserControl):

private void ViewInitialized(object sender, System.EventArgs e)
{
    this.SearchButton.Focus();
}

Answer 2

您需要在视图上预订Loaded事件，并在事件处理程序方法中调用按钮上的Focus（）。

Answer 3

It seemed to bit a bit strange...
IsVisibleChanged ... no reaction
Initialized ... no reaction
Loaded ... no reaction

And then I got the solution. What if the runtime uses the same View for each tab and changes only the data inside to another ViewModel. So the solution is:

    private void SameViewButDataContextChanged(object sender, System.Windows.DependencyPropertyChangedEventArgs e)
    {
        ChangeFocusDelegate focusDelegate = FocusFileSearchButton;
        Dispatcher.BeginInvoke(DispatcherPriority.ContextIdle, focusDelegate);
    }

And each time I add a tab the focus is switched to the Search button.