WPF中的密码眼不起作用

Question

我正在尝试使用WPF密码，但我无法理解为什么它不起作用。

我希望隐藏密码，当用户点击眼睛时，密码就会显示出来。

我们的想法是创建一个隐藏的文本框和可见的密码框，当用户点击眼睛按钮时，文本框将可见，密码框将被隐藏，这是我的代码：

XAML：

<PasswordBox x:Name="passwordBox"  HorizontalAlignment="Left" Height="27" Margin="102,37,0,0"  VerticalAlignment="Top" Width="140"/>
                        <TextBox x:Name="password_textbox"  HorizontalAlignment="Left" Height="27" Margin="102,37,0,0"  VerticalAlignment="Top" Width="140" Visibility="Collapsed"/>
                        <Button x:Name="eye_button" Background="White"  HorizontalAlignment="Left" Height="27" Margin="242,37,0,0" VerticalAlignment="Top" Width="30"  MouseDown="MouseDown" MouseUp="MouseUp"/>

代码背后：

      public MyPage()
        {
            InitializeComponent();
            eye_button.PreviewMouseUp += MouseUp;
            eye_button.PreviewMouseUp += MouseDown;           
        }
        .
        .
        .
        void MouseUp(Object sender , RoutedEventArgs args)
        {          
        password_textbox.Text = "aaaaaaaa";
        passwordBox.Visibility = Visibility.Collapsed;
        password_textBox.Visibility = Visibility.Visible;
        password_textBox.Focus();
        }

        void MouseDown(Object sender , RoutedEventArgs args)
        {        
        passwordBox.Visibility = Visibility.Visible;
        password_textBox.Visibility = Visibility.Collapsed;          
        passwordBox.Focus();
        }