New Windows means ExitWindowsEx uses SendMessageTimeout to transmit WM_QUERYENDSESSION to any or all most useful-level programs

This situation is indeed prevalent discover a purpose titled PostQuitMessage to help you article WM_Stop. PostMessage always works more effectively when you wish to help you simulate a demand otherwise type in event by the send WM_Demand otherwise one of several piano or mouse texts (which is usually dicey, incidentally). That it holds true because “real” enter in occurrences constantly have sequences off associated texts (such as keydown/keyup pairs) plus software gets befuddled if you attempt in order to process a separate type in message in the middle of one sequences. Article works more effectively when simulating enter in. Either you must have fun with PostMessage to find as much as a good quirk or insect to eliminate unlimited recursion. Like, guess your own WM_SETFOCUS handler (OnSetFocus) identifies your the new attract window isn’t good for certain reasoning and you have to evolve the focus to another windows.

For individuals who call SetFocus from the inside Lover Whirl anmeldelser their OnSetFocus handler, Screen quickly directs another WM_SETFOCUS messagea€”while you’re still processing the first you to definitely!

As a result, infinite regress until the stack blows upwards. To end that it infelicity, you might article a contact to yourselfa€”MYWM_SWITCHFOCUSa€”thus OnSetFocus is wind up one which just techniques the content to alter the focus. This is certainly those types of advice that is easier to understand into the routine than written down. What is important to remember would be the fact Windows wouldn’t enable you to SetFocus within a WM_SETFOCUS handler. While the SendMessage phone calls the fresh new window proc in person, it takes a keen HWND. How else does it know which content proc to name? But PostMessage adds the message to the content queue, that is regarding the a bond otherwise process, maybe not a window.

// post message so you're able to myself 
PostMessage(NULL, WM_HI_THERE_Good-looking, . ); 

That’s, it attempts to getting nice giving for every single software a go to help you die gracefully, in case an application will not function eventually, ExitWindowsEx eliminates this new software anyway

Whether your HWND is actually NULL, PostMessage postings the content to the present powering thread’s message queue. In practice, this feature actually severely helpful since the majority moments we should article a message to a different bond (possibly that have PostThreadMessage); however, discover usually rare factors when it’s smoother to share to help you oneself rather than a windows. (If you feel of every, delight tell me.) In case you think you’re begin to learn when to explore SendMessage and PostMessage, there are three way more content-giving properties you have to know on the: SendMessageCallback, SendNotifyMessage, and SendMessageTimeout. These types of functions are useful from the heady realm of Win32A® and you can multithreading. In Win32, for people who phone call SendMessage the thread is prohibited through to the address thread techniques the content. In the event your target bond are in itself banned for many most other need, SendMessage never ever production. Oops. SendNotifyMessage, SendMessageTimeout, and SendMessageCallback have been devised to work with this problem. SendNotifyMessage functions such as for instance SendMessage in case the target window belongs to (is made because of the) the present day thread; it truly does work particularly PostMessage in the event your window belongs to a new thread. SendMessageTimeout is similar, nonetheless it lets you specify a maximum for you personally to wait a little for the other thread to react. Too crappy, so unfortunate. SendMessageTimeout waits, yet not permanently. Since you you are going to imagine, SendMessageCallback takes a callback means. It sends the content and production instantaneously; if the content could have been processed, Screen calls the mode. SendMessageCallback comes in convenient whenever you may like to have fun with PostMessage, however would like to know if message could have been managed. View it as the PostMessage having money bill. PostMessage, SendMessageTimeout, and you will SendNotifyMessage are common a beneficial people to utilize if you like to broadcast an email to all or any greatest-height window by using HWND_TOPMOST as HWND. It is an awful idea to make use of HWND_TOPMOST that have SendMessage because that dry process results in your application to a stop. Contour 2 sumong various message-delivering functions. Whew!