[DialogResult] Add TryAgain and Continue (result 10, and 11) respectively.

[AraHaan]

Resolves #4712.

Proposed changes

• Adding TryAgain and Continue to DiagloResult.
• Adding CancelTryContinue to MessageBoxButtons.
• Adding Button4 to MessageBoxDefaultButton.
• Simplifying some code to ShowCore in MessageBox class to remove the need for the Win32ToDialogResult method.

Customer Impact

• Allows users to show MessageBox's with the Cancel, Try again, and continue buttons.
• Allows them to be able to check if TryAgain or Continue was pressed specifically on a MessageBox.

Regression?

• Yes / No
  No

Risk

• With this, the current plan is for .NET 6 and above to get this new API, because of that the risk should be minimal.

Screenshots

Not sure if this is considered a UI change. Left it in case it is.

Before

After

Test methodology

• Manual Testing with the added tests.

Accessibility testing

Not sure if this is considered a UI change. Left it in case it is.

Test environment(s)

.NET SDK (reflecting any global.json):
 Version:   6.0.100-preview.2.21155.3
 Commit:    1a9103db2d

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.21343
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\6.0.100-preview.2.21155.3\

Host (useful for support):
  Version: 6.0.0-preview.2.21154.6
  Commit:  3eaf1f316b

.NET SDKs installed:
  5.0.200-preview.21077.7 [C:\Program Files\dotnet\sdk]
  6.0.100-preview.2.21155.3 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.All 2.1.23 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.23 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.0.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.0-preview.2.21154.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.23 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.0.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.0-preview.2.21154.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.0.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 3.1.9 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.0-preview.2.21154.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET runtimes or SDKs:
  https://aka.ms/dotnet-download

Microsoft Reviewers: Open in CodeFlow

[codecov]

Codecov Report

Merging #4746 (0423ba6) into main (129d44a) will decrease coverage by 0.01812%.
The diff coverage is n/a.

❗ Current head 0423ba6 differs from pull request most recent head 296dca1. Consider uploading reports for the commit 296dca1 to get more accurate results

@@                 Coverage Diff                 @@
##                main       #4746         +/-   ##
===================================================
- Coverage   97.97301%   97.95489%   -0.01812%     
===================================================
  Files            543         548          +5     
  Lines         264728      266049       +1321     
  Branches        5007        5112        +105     
===================================================
+ Hits          259362      260608       +1246     
- Misses          4486        4547         +61     
- Partials         880         894         +14     

Flag	Coverage Δ
Debug	97.95489% <ø> (-0.01812%)	⬇️
test	97.95489% <ø> (-0.01812%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

[RussKie]

I don't believe we can add any unit tests here, but you can add a test app that exposes and features the new functionality to WinformsControlsTest project. Perhaps in a way similar to how we test "dialogs" or "task dialog" 🤔

[RussKie]

I'm converting this to draft until we get tests.

[RussKie]

I pushed an alternative version to how we can test the MessageBox functionality in a more robust way. It isn't exhaustive, but should give you an idea.

With that I discovered what looks like a bug in EnumConverter an by-design yet unexpected behaviour, so ignore it:

I also struggle to see how MessageBoxDefaultButton.Button4 can be used, as there doesn't seem a way to set 4 buttons.

[RussKie]

No, it doesn't look so. If you specify only 3 buttons but set the default button to 4, the app will crash.

[AraHaan]

I rebased this on top of the current tip of main and removed the code parts that are in #4809 from this PR.

[AraHaan]

@RussKie think the blocking label can be removed now?

[RussKie]

Yep :)

[AraHaan]

Sweet this looks 👌 to merge with all checks passing.

[RussKie]

Thank you