`MessageBox.Show` overload with `StartPosition` parameter

Background and motivation

When Messagebox.Show is called, often it will be associated to an open window. The messagebox will show in the middle of the monitor. This is not really user friendly when the user has a large monitor or when using non-maximized forms.

Example of users working around the problem: https://stackoverflow.com/questions/1732443/center-messagebox-in-parent-form

API Proposal

namespace System.Windows.Forms;

public enum MessageBoxStartPosition
{
Default = 0,
CenterScreen = 1,
CenterParent = 2
}

public static DialogResult Show(
            string? text,
            string? caption,
            MessageBoxButtons buttons,
            MessageBoxIcon icon,
            MessageBoxDefaultButton defaultButton,
            MessageBoxOptions options,
            MessageBoxStartPosition startPosition)

API Usage

MessageBox.Show("Test Message box text","Test Caption", 
MessageBoxButtons.OK, MessageBoxIcon.Error, MessageBoxStartPosition.CenterParent)

Alternative Designs

No response

Risks

No response

Will this feature affect UI controls?

No.

[RussKie]

Something like this should work:

// code
ShowMessage(owner, message, heading);


// 
private static void ShowMessage(I32Window owner, string message, string heading)
{
#if NET5_OR_GREATER
     MessageBox.Show(owner, message, heading);
#else
     TaskDialogPage page = new(...);
     TaskDiaglog.Show(owner, page);
#endif
}

[RussKie]

I agree that TD is a bit more verbose, but it’s also feature-ruch and (which is important) it is test-friendly. Migrating from MB to TD isn’t that difficult, one can add a quick helper method that would translate MB calls to comparable TD calls.