在屏幕键盘上显示鼠标左键按下PasswordBox，并在框外单击时应隐藏

Question

Platform: C# WPF

Environment: Visual Studio 2013

Question # 1 : I want to show third party on screen keyboard on mouse left button down on PasswordBox control of C# WPF. I used the following code:

private void PasswordBox_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    System.Diagnostics.Process.Start("D:\\CCOnScreenKeyboard.exe"); 
}

But it does not start on screen key board. Instead it triggers on MouseDoubleClick and GotFocus events.

Question # 2 :

I want to Hide on screen keyboard when mouse click outside the PasswordBox and Show again on mouse left button down inside box.

Question # 3 :

I want to show keyboard on single click instead of mouse double click

Answer 1

I belive the best way to do this will be through using the Focus events, as you only want the keyboard when you're interacting with the PasswordBox , and for it to go once you have stopped interacting.

private void PasswordBox_GotFocus(object sender, RoutedEventArgs e) => 
    Process.Start("D:\\CCOnScreenKeyboard.exe");

private void PasswordBox_LostFocus(object sender, RoutedEventArgs e)
{
    foreach (var process in Process.GetProcessesByName("CCOnScreenKeyboard"))
        process.Kill();
}

Answer 2

You could handle the PreviewMouseLeftButtonDown event for the parent window. Something like this:

bool isVisible = false;
PreviewMouseLeftButtonDown += (ss, ee) => 
{
    if (!passwordBox.IsMouseOver && isVisible)
    {
        System.Diagnostics.Process.GetProcessesByName("CCOnScreenKeyboard")?.FirstOrDefault()?.Kill();
    }
    else if (!isVisible)
    {
        System.Diagnostics.Process.Start("D:\\CCOnScreenKeyboard.exe");
        isVisible = true;

    }
};