Background and motivation

Issue #5795 suggests getting more MessageBoxButton and MessageBoxResult values available and bringing Wpf repository more in sync with what is available in WinForms repository.

It will also make it easier to migrate from WinForms to WPF that you can practically directly make the same call to show a MessageBox in WPF as in WinForms.

Both repositories are calling into the same MessageBox function in Windows, so it should not be a technical problem to handle this.

API Proposal

Extend MessageBoxButton and MessageBoxResult enumerations

Add AbortRetryIgnore, RetryCancel and CancelTryContinue to the MessageBoxButton enumeration:

namespace System.Windows
{
    public enum MessageBoxButton
    {
        OK = 0,
        OKCancel = 1,
+       AbortRetryIgnore = 2,
        YesNoCancel = 3,
        YesNo = 4,
+       RetryCancel = 5,
+       CancelTryContinue = 6,
    }
}

Also add Abort, Retry, Ignore, TryAgain and Continue to the MessageBoxResult enumeration:

namespace System.Windows
{
    public enum MessageBoxResult
    {
        None = 0,
        OK = 1,
        Cancel = 2,
+       Abort = 3,
+       Retry = 4,
+       Ignore = 5,
        Yes = 6,
        No = 7,
+       TryAgain = 10,
+       Continue = 11,
    }
}

API Usage

// Call the MessageBox.Show with additional parameters

MessageBoxResult result = MessageBox.Show("Operation timed out. What would you like to do?", 
    "My application",
    MessageBoxButton.RetryCancel,
    MessageBoxIcon.Question,
    MessageBoxResult.Retry);
if (result == MessageBoxResult.Retry)
{
    /// Perfom code to retry operation
}
else
{
    // Log cancel request and exit
}

Alternative Designs

No response

Risks

In connection with the extra enumeration values, I don't see a risk, since the values already exist in the underlying Windows API (1).

1. https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-messagebox