Question

I am trying to make a TextBox behavior for an on-screen keyboard, it can update the text in the textbox but I can’t get it to focus the textbox and move the caret to the end of the text once it’s done updating.

I have tried using TextBox.Focus() and TextBox.Select() in both orders with no luck.

Thanks for your time

Answer 1

Changing the focus from within an input event handler (i.e. mouse click on a virtual key) will fail, since the mouse-up event (or key-up) will return the focus to the original element. In order to make it work, you have to dispatch the focus command to a later time using the Dispatcher object.

Example:

Dispatcher.Invoke(new Action(() =>
{
    textBox1.Focus();
    textBox1.SelectionStart = textBox1.Text.Length;
    // or textBox1.Select(textBox1.Text.Length,0);
}), System.Windows.Threading.DispatcherPriority.Background);