A quick Google indicates the only difference between PostMessage and SendMessage is that PostMessage returns immediately while SendMessage waits for the recipient to process the message.

You are correct, but you have missed the significance.

  1. SendMessage is a synchronous call.

    If the timer handler -- your custom function -- takes a long time to run, it will cause your GUI to freeze until it is finished.

  2. PostMessage() is an asynchronous call;

    The message is added to the queue and processed when it reaches the top. This allowing the originator of the message to do other things during the interim.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re^3: Win32::GUI sending Windows messages between threads by BrowserUk
in thread Win32::GUI sending Windows messages between threads [solved] by shadrack

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