Accessibility: NRE announcing changed item in PropertyGrid

[M-Lipin]

Fixes #1997

Proposed changes

• Adding test for null before announcement changed item details as changed item can be disposed in case Property grid is recreated on new value submit.
• Announcement is not broken and this case is rare. It is ok to not announce the value of disposed and recreated PropertyGrid.

Customer Impact

• Customers will not experience application crash in case the PropertyGrid control can be recreated in Form lifecycle.

Regression?

• Yes (before introducing announcements for PropertyGrid value updates there was no issue)

Risk

• None (just one additional null value test)

Screenshots

Before

Crash stack:

  System.Windows.Forms.dll!System.Windows.Forms.PropertyGridInternal.PropertyGridView.GridViewEdit.ProcessDialogKey(System.Windows.Forms.Keys keyData) Line 6808 C# Symbols loaded.
  System.Windows.Forms.dll!System.Windows.Forms.PropertyGridInternal.PropertyGridView.GridViewEdit.OnKeyDown(System.Windows.Forms.KeyEventArgs ke) Line 6693 C# Symbols loaded.
  System.Windows.Forms.dll!System.Windows.Forms.Control.ProcessKeyEventArgs(ref System.Windows.Forms.Message m) Line 10649 C# Symbols loaded.
  System.Windows.Forms.dll!System.Windows.Forms.Control.ProcessKeyMessage(ref System.Windows.Forms.Message m) Line 10695 C# Symbols loaded.
  System.Windows.Forms.dll!System.Windows.Forms.Control.WmKeyChar(ref System.Windows.Forms.Message m) Line 13328 C# Symbols loaded.

After

No crash.

Test methodology

• Manual testing.
• Automation testing (to be run)
• Unit tests (to be implemented)

Accessibility testing

Test environment(s)

.NET Core SDK (reflecting any global.json):
Version: 3.1.100-preview1-014044
Commit: dca04e7030
Runtime Environment:
OS Name: Windows
OS Version: 10.0.18362
OS Platform: Windows

Microsoft Reviewers: Open in CodeFlow

[codecov]

Codecov Report

Merging #1998 into release/3.1 will increase coverage by 0.00193%.
The diff coverage is 0%.

@@                  Coverage Diff                  @@
##           release/3.1       #1998         +/-   ##
=====================================================
+ Coverage      26.5056%   26.50754%   +0.00194%     
=====================================================
  Files              805         805                 
  Lines           268083      268086          +3     
  Branches         38068       38069          +1     
=====================================================
+ Hits             71057       71063          +6     
+ Misses          191947      191942          -5     
- Partials          5079        5081          +2

Flag	Coverage Δ
#Debug	26.50754% <0%> (+0.00193%)	⬆️
#production	26.50754% <0%> (+0.00193%)	⬆️
#test	?

[merriemcgaw]

Approved in tactics

[zsd4yr]

@msftbot please merge after 24 hours

[ghost]

Hello @zsd4yr!

Because you've given me some instructions on how to help merge this pull request, I'll be modifying my merge approach. Here's how I understand your requirements for merging this pull request:

• I won't merge this pull request until after the UTC date Fri, 11 Oct 2019 19:30:07 GMT, which is in 1 day

If this doesn't seem right to you, you can tell me to cancel these instructions and use the auto-merge policy that has been configured for this repository. Try telling me "forget everything I just told you".

[zsd4yr]

@msftbot nevermind.

Tactics has technically not opened the 3.1 gate yet

[RussKie]

@zsd4yr we're still waiting for QA sign off, so we shouldn't be merging it just yet

[merriemcgaw]

@Vino-Wang has CTI picked up this PR yet?

[Vino-Wang]

@merriemcgaw, we got it today, will test it and update test results in Teams thread.

[M-Lipin]

Rebased on top of release/3.1 to get all new fixes in the feature branch.

[M-Lipin]

Fix passed QA verification.