[:de]C# .NET WinForms: Placeholder für TextBox setzen[:en]C# .NET WinForms: Setting a placeholder for a TextBox[:]

Last Updated on 2019-04-11.

[:en]Useful snippet for adding a placeholder text feature to a common Windows Forms TextBox like you might know it from HTML’s <input> tag.

Add e.g. to your ExtensionMethods:

private const int EM_SETCUEBANNER = 0x1501;
[DllImport("user32.dll", CharSet = CharSet.Auto)]
private static extern Int32 SendMessage(IntPtr hWnd, int msg, int wParam, [MarshalAs(UnmanagedType.LPWStr)]string lParam);

public static void SetPlaceholder(this TextBox box, string text)
{
    SendMessage(box.Handle, EM_SETCUEBANNER, 0, text);
}

Result:

 

 

Reference[:]