The fresh new Window setting ExitWindowsEx spends SendMessageTimeout to deliver WM_QUERYENDSESSION to all the best-top applications

This case is really prevalent there clearly was a function named PostQuitMessage to help you post WM_End. PostMessage always works better if you want in order to imitate a command otherwise type in enjoy because of the publish WM_Order otherwise one of the guitar otherwise mouse texts (that is usually dicey, by the way). This is true as the « real » enter in incidents usually can be found asiandate hesabД± nasД±l silinir in sequences of associated texts (like keydown/keyup pairs) as well as your app could get befuddled if you attempt to techniques another type of type in message in the center of one of these sequences. Blog post works better whenever simulating input. Possibly you have got to use PostMessage to find around an effective quirk or insect to end unlimited recursion. Instance, assume your WM_SETFOCUS handler (OnSetFocus) find that the the focus windows isn’t perfect for particular need and you have to switch the focus to some other window.

For people who name SetFocus from within your own OnSetFocus handler, Window immediately delivers another WM_SETFOCUS messagea€ »while you are nonetheless processing the first one!

The result is infinite regress until your own heap punches up. To get rid of that it infelicity, you can blog post a message so you can yourselfa€ »MYWM_SWITCHFOCUSa€ »therefore OnSetFocus can also be finish before you can procedure the content to switch the focus. This really is those types of instances which is simpler to know during the habit than in writing. It is essential to keep in mind is that Windows would not allow you to SetFocus inside a beneficial WM_SETFOCUS handler. While the SendMessage phone calls the fresh screen proc in person, it needs an enthusiastic HWND. How else does it discover and that message proc to call? However, PostMessage adds the message toward message waiting line, that’s for the a bond otherwise procedure, not a screen.

// post content to myself 
PostMessage(NULL, WM_HI_THERE_Handsome, . ); 

That is, it tries to getting sweet by providing for every single app a chance to help you perish gracefully, but if an application will not respond at some point, ExitWindowsEx kills the brand new software in any event

In case your HWND is actually NULL, PostMessage listings the message to the present powering thread’s message waiting line. Used, this feature is not terribly beneficial since most minutes you want to post a contact to another thread (maybe which have PostThreadMessage); but you’ll find always unusual points when it’s smoother to create in order to oneself instead a windows. (If you were to think of any, please tell me.) In case you envision you might be beginning to know when to use SendMessage and you can PostMessage, you can find about three significantly more message-giving qualities you have to know on: SendMessageCallback, SendNotifyMessage, and SendMessageTimeout. This type of functions are useful about heady realm of Win32A® and you can multithreading. Into the Win32, if you name SendMessage your own bond is actually prohibited before target bond processes the content. When your target thread is actually alone blocked for the majority most other reason, SendMessage never ever productivity. Oops. SendNotifyMessage, SendMessageTimeout, and SendMessageCallback had been conceived to be hired around this condition. SendNotifyMessage really works for example SendMessage should your target screen falls under (was developed by) the current thread; it truly does work eg PostMessage in the event the screen belongs to a separate bond. SendMessageTimeout is comparable, it enables you to indicate a max time and energy to wait a little for the other bond to respond. Too bad, therefore sad. SendMessageTimeout delays, yet not forever. As you you are going to assume, SendMessageCallback takes a beneficial callback mode. They delivers the content and you may productivity instantly; when the message might have been canned, Window phone calls their setting. SendMessageCallback will come in convenient whenever you desire to fool around with PostMessage, however wish to know in the event the message might have been addressed. Think of it since PostMessage which have income receipt. PostMessage, SendMessageTimeout, and you can SendNotifyMessage are common an effective individuals to use if you prefer so you’re able to aired a message to all the finest-top windows that with HWND_TOPMOST because HWND. It is an awful idea to utilize HWND_TOPMOST with SendMessage while the that lifeless processes may bring your own app in order to a halt. Shape 2 sumong various message-delivering services. Whew!