文本框显示并全选,该如何解决

文本框显示并全选

<Grid KeyDown="Grid_KeyDown">

        <TextBlock x:Name="tbkTitle" HorizontalAlignment="Center" VerticalAlignment="Center" MouseLeftButtonDown="tbkTitle_MouseLeftButtonDown"/>

        <TextBox x:Name="tbTitle" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Visibility="Collapsed" LostKeyboardFocus="tbTitle_LostKeyboardFocus" Height="20" FontFamily="Arial" FontSize="12"/>

    </Grid>

有一个TextBlock和TextBox,点击TextBlock让TextBox显示出来,并全选内容,  WPF新手
------解决思路----------------------
在TextBlock的Preview 中的MouseLeftButtonDown 事件中 控制textBox的Visibility属性。 全选的话 有SelectAll 方法。
------解决思路----------------------

 <Grid >

        <TextBlock x:Name="tbkTitle" Text="click me" HorizontalAlignment="Center" VerticalAlignment="Center" MouseLeftButtonDown="tbkTitle_MouseLeftButtonDown"/>

        <TextBox x:Name="tbTitle" Text="textboxcontent" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Visibility="Collapsed"  Height="20" FontFamily="Arial" FontSize="12"/>

    </Grid>

private void tbkTitle_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)

        {

            AllowChange();

        }



        public void AllowChange()

        {

            tbTitle.Focus();

            tbTitle.SelectAll(); 

            this.tbTitle.Visibility = System.Windows.Visibility.Visible;

        }