How to show a message box before the application main window is launched

Introduction

There are scenarios where we have to show a standalone message box even before the application main window is launched. In such scenario, we need to do something different. Say if we have a composite application with a bootstrapper, and we want to show some error while running a bootstrapper, it may look difficult because we don’t have a parent window. In such scenario, we can show the message box as shown below.

private static void ShowError(string message)
{            
/* We cannot show a message out in void. So we are creating a dummy window and setting visibility as hidden. we will then use this as the parent of the message box. */

var w = new Window() { Height = 0, Width = 0, Visibility = Visibility.Hidden, WindowStyle = WindowStyle.None };

w.Show();
System.Windows.MessageBox.Show(w, message);
w.Close();
}

Here we will create and show a window where the visibility of the window is set to hidden, now we will use this window as the parent of the message box and will show the message box.