Narrator doesn't announce a text mouse selection in DataGridVIewTextBoxCell and ToolStripTextBox

[vladimir-krestov]

• .NET Core Version: 5.0.100-alpha.1.20073.10

• Have you experienced this same bug with .NET Framework?: TextPattern hasn't implemented in .Net 4.8 yet.

Problem description:

• Narrator doesn't read symbols and a selected text range in DataGridViewTextBoxCell and ToolStripTextBox edit controls when using a keyboard or mouse selecting
  This seems to be due to incorrect handling of keyboard arrow keys pressing.
  (Please check ProcessDialogKey method)
  But if you change the focus and return then Narrator chooses the correct selected range.
  

Expected behavior:

• Narrator reads symbols and a selected text range as in TextBox, ComboBox
  

Minimal repro:

• Create a .Net Core 5.0 app
• Add ToolStrip or DataGridView with TextBox items
• Run app and Narrator
• Check text announcing

[vladimir-krestov]

Related PR #2701

[merriemcgaw]

In general Narrator users won't be using a mouse to navigate the DGV. Let's close this one until/unless we get specific feedback from a customer or compliance tester that we need to do something here. This is a high risk, high cost issue so we will do it if/when it is raised by customer.