WPF: Can't get my control to take focus

I can't seem to get my control to actually take the focus:

XAML:

<Button Command={Binding SetGridToVisibleCommand} />
<Grid Visibility="{Binding IsGridVisible, Converter={con:VisibilityBooleanConverter}}">
    <TextBox Text={Binding MyText} IsVisibleChanged="TextBox_IsVisibleChanged" />
</Grid>

XAML.cs:

private void TextBox_IsVisibleChanged(Object sender, DependencyPropertyChangedEventArgs e)
{
    UIElement element = sender as UIElement;

    if (element != null)
    {
        Boolean success = element.Focus(); //Always returns false and doesn't take focus.
    }
}

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The ViewModel 开发者_开发问答does it's job of setting the IsGridVisible to true, and the converter does it's job by converting that value to Visibility.Visible (I snooped it).

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Not all UIElements can be focused by default, have you tried setting Focusable to true before trying Focus()?

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We use this with in our application:

public static class Initial
{
    public static void SetFocus(DependencyObject obj, bool value)
    {
        obj.SetValue(FocusProperty, value);
    }

    public static readonly DependencyProperty FocusProperty =
            DependencyProperty.RegisterAttached(
             "Focus", typeof(bool), typeof(Initial),
             new UIPropertyMetadata(false, HandleFocusPropertyChanged));

    private static void HandleFocusPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var element = (UIElement)d;
        if ((bool)e.NewValue)
            element.Focus(); // Ignore false values.
    }
}

And the usage is:

<TextBox Text="{Binding FooProperty, UpdateSourceTrigger=PropertyChanged}"
         Grid.Column="1" HorizontalAlignment="Stretch"
         Style="{StaticResource EditText}" ui:Initial.Focus="True"/>

The original idea came from SO, but couldn't find the answer. 100% free code behind :P

HTH

---

I couldn't reproduce your problem, its working fine with me, try the following code on a new project as a proof of concept and see if it works with you:

<Window x:Class="WpfApplication2.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<StackPanel>
    <Button Content="Click" Click="Button_Click" />
        <Grid>
            <TextBox Name="NameTextBox" Text="ddd"
                     IsVisibleChanged="TextBox_IsVisibleChanged" />
        </Grid>
</StackPanel>

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void TextBox_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
    {
        UIElement element = sender as UIElement;

        if (element != null)
        {
            Boolean success = element.Focus(); //Always returns false and doesn't take focus.
        }
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        if (NameTextBox.IsVisible)
            NameTextBox.Visibility = Visibility.Collapsed;
        else
            NameTextBox.Visibility = Visibility.Visible;
    }
}