[release/8.0] Allows DataGridView to start row/column on index 1 on Narrator

[LeafShi1]

Backport #10243 to release/8.0

Fixes #13994

Proposed changes

• Creates a new switch that allows developers to configure their application to make the starting index of rows/cells in DataGridView to be read by Narrator from 1, instead of 0;
• Adds checks on rows and cells of DataGridView to see if the switch is true. If true, starting index of rows/cells will be 1, instead of 0.

Customer Impact

• Developers will be able to configure their WinForms DataGridView rows/cells to be read by Narrator from index 1, instead of 0.

Regression?

• No

Risk

• Low

Test methodology

• Manual testing
• Unit tests

Microsoft Reviewers: Open in CodeFlow

[merriemcgaw]

Thanks!

[merriemcgaw]

@KlausLoeffelmann @Shyam-Gupta I'd like you two to weigh in before we take this. It was approved by Tactics, but I realized that this adds the switch which enables the starting count at 1 rather than 0. That's a behavior change, but @LeafShi1 can tell us whether this new behavior is enabled by default or not. The SSMA team would still have to update their app to turn on the feature if I'm not mistaken. We could never turn this on by default, and if they can't enable this, then maybe we don't need it in servicing and they can just take it when they get to migrate from 8->10.

[LeafShi1]

@LeafShi1 can tell us whether this new behavior is enabled by default or not.

it's enabled by default

winforms/src/System.Windows.Forms/System/Windows/Forms/Controls/DataGridView/DataGridViewRow.DataGridViewRowAccessibleObject.cs

Line 138 in 09c759b

private static int RowStartIndex => AppContextSwitches.DataGridViewUIAStartRowCountAtZero ? 0 : 1;