The CellParsing event of the datagridview can't be invoked when changing the value of the cell firstly

[Zheng-Li01]

• .NET Core Version: (3.0.100-preview6-12253 from release branch)
• Have you experienced this same bug with .NET Framework?: No

More info:
The issue also can reproduce on the 3.0.100-preview7-12261 from master branch.

Repro Steps:

1. Build and run the attached application.
   test1.zip
2. Try to change the first cell value from “1” to “a1”.
3. Click another cell using mouse.
4. Repeat the step2 & step3.

Actually Results:
After step3: The CellParsing event of the datagridview didn't invoke, and the value still is “1”,not be changed to “a1”.
After step4: The CellParsing event of the datagridview can be invoked, and the value was changed to “a1”.

Expected:
After step3:
The CellParsing event of the datagridview can be invoked, and the value was changed to “a1”.

[zsd4yr]

@Zheng-Li01 is this a regression of .NET Core from the Framework or a regression within .NET Core only?

[Zheng-Li01]

@zsd4yr, the issue is not a regression from the Framework, which is a regression within .NET Core only,
The issue also can reproduce on the .NET Core SDK 3.0.100-preview6-01226 from release branch and 3.0.100-preview6-012162 from master branch, but the issue can't reproduce on the .NET Core SDK 3.0.100-preview6-012101 build from master branch.

[zsd4yr]

@danmosemsft could this be a regression lower in the stack? I feel like we just send these kinds of things downlevel to validate, but I could be wrong. @merriemcgaw, ideas?

[RussKie]

Progress update:

I have spent a considerable amount of time on this, the logic is quite arcane.
My current conclusion that the issue is somehow caused by the removal of AccessibilityImprovements.Level3 quirks in #754. I will follow up with @M-Lipin to confirm my findings.

[M-Lipin]

It seems that we need to delay accessing DataGridView.EditingControlAccessibleObject until corresponding EditingControl is initialized and its handle is created.