How to open text in Notepad from .NET?

Question

When I click a button on a Windows Forms form, I would like to open a Notepad window containing the text from a TextBox control on the form.

How can I do that?

Answer 1

For non ASCII user.

[DllImport("User32.dll", EntryPoint = "SendMessage", CharSet = CharSet.Unicode)]
private static extern int SendMessage(IntPtr hWnd, int uMsg, int wParam, string lParam);

Based on @Peter Mortensen answer

Add CharSet = CharSet.Unicode to the attribute for supporting Unicode characters