How to clear textbox and passwordbox after clicking?

Question

WPF

When the textbox is clicked, its initial content should be cleared.
I hung up the MouseLeftButtonDown event on the textbox and did this:

private void tb_click(object sender, MouseButtonEventArgs e)
        {
           textbox1.Text = "";
        }

But, unfortunately, nothing has changed. What am I doing wrong?
Using markup, prescribed - After double clicking it is deleted, I need after 1 MouseDoubleClick="tb_click"

Answer 1

Use PreviewMouseLeftButtonDown

private void TextBox1_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
 {
      TextBox1.Text = "";
 }