How to stop search process in Automation?

Question

D.D.K-2637 966

Hi,

Is there a way to safely terminate the IUIAutomation search process?

Here is the code I am using:

element->GetCurrentPatternAs(UIA_TextPatternId, IID_PPV_ARGS(&telement));

I created a keyboard_hook that stops my code.

However, if I press the escape key while the search is in progress, the application crashes..

Screenshot_2

Thanks you!

Jeanine Zhang-MSFT 11,356 Reputation points Microsoft External Staff

2023-09-13T02:47:35.7633333+00:00

The best practice is to follow the Component Object Model (COM) standard and avoid destroying the event handler object until its reference count has reached zero. Destroying an event handler immediately after unsubscribing for events may result in an access violation if an event is delivered late.
Jeanine Zhang-MSFT 11,356 Reputation points Microsoft External Staff

2023-09-15T08:33:33.5233333+00:00

Have you got any updates about this issue? Could you please check my suggestion?
D.D.K-2637 966 Reputation points

2023-09-17T05:43:34.7433333+00:00

Hi @Jeanine Zhang-MSFT ,

Thanks you but I'm still stuck because immediately stopping this process is necessary for my application. Perhaps I will issue a note to those who use them in the coming days.
RLWA32 49,551 Reputation points

2023-09-17T06:02:14.0833333+00:00

Maybe you can can cancel the UIAutomation call with CoCancelCall function. Some related material -- How do I protect myself against a COM call that can hang? I’m already running the server out-of-process.

Your answer

Jeanine Zhang-MSFT 11,356 Reputation points Microsoft External Staff

2023-09-13T02:47:35.7633333+00:00

The best practice is to follow the Component Object Model (COM) standard and avoid destroying the event handler object until its reference count has reached zero. Destroying an event handler immediately after unsubscribing for events may result in an access violation if an event is delivered late.
Jeanine Zhang-MSFT 11,356 Reputation points Microsoft External Staff

2023-09-15T08:33:33.5233333+00:00

Have you got any updates about this issue? Could you please check my suggestion?
D.D.K-2637 966 Reputation points

2023-09-17T05:43:34.7433333+00:00

Hi @Jeanine Zhang-MSFT ,

Thanks you but I'm still stuck because immediately stopping this process is necessary for my application. Perhaps I will issue a note to those who use them in the coming days.
RLWA32 49,551 Reputation points

2023-09-17T06:02:14.0833333+00:00

Maybe you can can cancel the UIAutomation call with CoCancelCall function. Some related material -- How do I protect myself against a COM call that can hang? I’m already running the server out-of-process.