[Accessibility] Pressing Up/Down keyboard in drop-down list of property collapses drop-down directly

[Olina-Zhang]

.NET version

10.0.100-alpha.1.24553.6

Did it work in .NET Framework?

No

Did it work in any of the earlier releases of .NET Core or .NET 5+?

No, all versions have this issue

Issue description

Pressing Up/Down keyboard in drop-down list of property collapses dropdown directly.

Expand Result: Drop-down list keeps expanding state when pressing Up/Down keyboard, then pressing Enter can collapse it

Steps to reproduce

Repro steps:

1. Find one property with dropdown list in PropertyGrid, for example: Multiline
2. Tab to its value part: False, then press Up keyboard to change value: True --- it is necessary step
3. Press Alt+Down or F4 to expand this property's drop-down list
4. Press Down keyboard to choose another value: False

[merriemcgaw]

@LeafShi1 you were working on a related issue with drop downs. Should we make sure fixing this behavior is included in your fix before we service?

[LeafShi1]

@LeafShi1 you were working on a related issue with drop downs. Should we make sure fixing this behavior is included in your fix before we service?

This problem occurs in the drop-down box that is expanded by the shortcut key after changing the property value, and this problem occurs in all properties. I am investigating this problem.

The call stack:

>	System.Windows.Forms.dll!System.Windows.Forms.PropertyGridInternal.PropertyGridView.CloseDropDownInternal(bool resetFocus) Line 794	C#
 	System.Windows.Forms.dll!System.Windows.Forms.PropertyGridInternal.PropertyGridView.DropDownHolder.WndProc(ref System.Windows.Forms.Message m) Line 670	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.OnMessage(ref System.Windows.Forms.Message m) Line 66	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.WndProc(ref System.Windows.Forms.Message m) Line 115	C#
 	System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(Windows.Win32.Foundation.HWND hWnd, uint msg, Windows.Win32.Foundation.WPARAM wparam, Windows.Win32.Foundation.LPARAM lparam) Line 351	C#
 	[Native to Managed Transition]	
 	[Managed to Native Transition]	
 	System.Windows.Forms.dll!System.Windows.Forms.Application.LightThreadContext.FPushMessageLoop(Microsoft.Office.msoloop uReason) Line 83	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Application.LightThreadContext.RunMessageLoop(Microsoft.Office.msoloop reason, bool fullModal) Line 26	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Microsoft.Office.msoloop reason, System.Windows.Forms.ApplicationContext context) Line 808	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Microsoft.Office.msoloop reason, System.Windows.Forms.ApplicationContext context) Line 695	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Application.DoEventsModal() Line 909	C#
 	System.Windows.Forms.dll!System.Windows.Forms.PropertyGridInternal.PropertyGridView.DropDownHolder.DoModalLoop() Line 166	C#
 	System.Windows.Forms.dll!System.Windows.Forms.PropertyGridInternal.PropertyGridView.DropDownControl(System.Windows.Forms.Control control) Line 1464	C#
 	System.Windows.Forms.dll!System.Windows.Forms.PropertyGridInternal.PropertyGridView.PopupEditor(int row) Line 3735	C#
 	System.Windows.Forms.dll!System.Windows.Forms.PropertyGridInternal.PropertyGridView.F4Selection(bool popupModalDialog) Line 1212	C#
 	System.Windows.Forms.dll!System.Windows.Forms.PropertyGridInternal.PropertyGridView.GridViewTextBox.ProcessDialogKey(System.Windows.Forms.Keys keyData) Line 260	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Control.PreProcessMessage(ref System.Windows.Forms.Message msg) Line 8545	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Control.PreProcessControlMessageInternal(System.Windows.Forms.Control target, ref System.Windows.Forms.Message message) Line 8620	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.PreTranslateMessage(ref Windows.Win32.UI.WindowsAndMessaging.MSG msg) Line 962	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Application.LightThreadContext.FPushMessageLoop(Microsoft.Office.msoloop uReason) Line 106	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Application.LightThreadContext.RunMessageLoop(Microsoft.Office.msoloop reason, bool fullModal) Line 26	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Microsoft.Office.msoloop reason, System.Windows.Forms.ApplicationContext context) Line 808	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Microsoft.Office.msoloop reason, System.Windows.Forms.ApplicationContext context) Line 695	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Application.RunDialog(System.Windows.Forms.Form form) Line 1324	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Form.ShowDialog(System.Windows.Forms.IWin32Window owner) Line 5674	C#
 	System.Windows.Forms.dll!System.Windows.Forms.Form.ShowDialog() Line 5559	C#

We can backport to 9.0 together after this problem is fixed