fix [Accessibility] Accessibility Insights tool keeps loading when mouse-over DataGridView #10343

[Epica3055]

Fix #10343

Related to PR_7349

Cause of this issue

Take a look here this PR_7349 had made

Same as this:
https://github.com/dotnet/winforms/pull/7349/files#diff-2cdcad323e7cd83529f6ded1cfd60aa6906ccbb32755221d36cdb67f72b507c0L306-L315

We can see this PR_7349 was to address memory leaks.

Indeed the code here was problematic because if there are no Accessibility Client listening to then there is no need to create AccessibilityObject

        protected override void OnHandleCreated(EventArgs e)
        {
            base.OnHandleCreated(e);
            if (IsHandleCreated)
            {
                // The null-check was added as a fix for a https://github.com/dotnet/winforms/issues/2138
                _dataGridView?.SetAccessibleObjectParent(AccessibilityObject);
            }
        }

The author addressed this problem by this

        protected override void OnHandleCreated(EventArgs e)
        {
            base.OnHandleCreated(e);

            // The null-check was added as a fix for a https://github.com/dotnet/winforms/issues/2138
            if (IsHandleCreated && _dataGridView?.IsAccessibilityObjectCreated == true)
            {
                _dataGridView.SetAccessibleObjectParent(AccessibilityObject);
            }
        }

But this posed another problem, when the handle is created before Accessibility Client is activated, the code here _dataGridView.SetAccessibleObjectParent(AccessibilityObject); never get a chance to be involved.

https://github.com/dotnet/winforms/blob/71aeb2e40dc2d6d7972e86665857c84cc7e8e02e/src/System.Windows.Forms/src/System/Windows/Forms/DataGridView/DataGridView.Methods.cs#L27496C4-L27507

As we can see: the editingControl has no parent.

Regression?

• Yes

Screenshots

Before

After

Test methodology

• manually

Test environment(s)

9.0.0-alpha.1.23572.27

[Tanya-Solyanik]

@Epica3055 - great fix and great explanation! Please make sure to test it for memory leaks.

[Tanya-Solyanik]

Very nice!

[Tanya-Solyanik]

Looks good, but I'm not sure about the shipped/unshipped API file changes. Please look up history of these files to see how we are removing overrides. I believe we are marking them with *REMOVED* string in the unshipped file.

[Tanya-Solyanik]

@Epica3055 - please send these privates to @Olina-Zhang for testing before porting to release/8.0

[Epica3055]

Olina tested this PR, and found there is a memory-leak problem.
I investigated and found that the memory-leak problem actually resulted from this PR:10407.
I also tried PropertyGrid and found there is a memory-leak problem too after this PR:10407.

[Epica3055]

/backport to release/8.0

[github-actions]

Started backporting to release/8.0: https://github.com/dotnet/winforms/actions/runs/7189547779

[github-actions]

@Epica3055 backporting to release/8.0 failed, the patch most likely resulted in conflicts:

$ git am --3way --ignore-whitespace --keep-non-patch changes.patch

Applying: fix [Accessibility] Accessibility Insights tool keeps loading when mouse-over DataGridView #10343
Using index info to reconstruct a base tree...
M	src/System.Windows.Forms/src/PublicAPI.Unshipped.txt
A	src/System.Windows.Forms/src/System/Windows/Forms/Controls/DataGridView/DataGridViewComboBoxEditingControl.cs
A	src/System.Windows.Forms/src/System/Windows/Forms/Controls/DataGridView/DataGridViewTextBoxEditingControl.cs
Falling back to patching base and 3-way merge...
Auto-merging src/System.Windows.Forms/src/System/Windows/Forms/DataGridViewTextBoxEditingControl.cs
Auto-merging src/System.Windows.Forms/src/System/Windows/Forms/DataGridViewComboBoxEditingControl.cs
Auto-merging src/System.Windows.Forms/src/PublicAPI.Unshipped.txt
CONFLICT (content): Merge conflict in src/System.Windows.Forms/src/PublicAPI.Unshipped.txt
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 fix [Accessibility] Accessibility Insights tool keeps loading when mouse-over DataGridView #10343
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!

[Tanya-Solyanik]

Olina tested this PR, and found there is a memory-leak problem. I investigated and found that the memory-leak problem actually resulted from this PR:10407. I also tried PropertyGrid and found there is a memory-leak problem too after this PR:10407.

@Epica3055 - Great investigation, thanks!