[Lazarus] PostMessage return value

Sven Barth pascaldragon at googlemail.com
Fri Sep 19 22:10:07 CEST 2014

Am 19.09.2014 14:49 schrieb "Xiangrong Fang" <xrfang at gmail.com>:
> 2014-09-19 18:23 GMT+08:00 Michael Schnell <mschnell at lumino.de>:
>> On 09/18/2014 10:32 AM, Xiangrong Fang wrote:
>> Unfortunately I do not get this working. When I instantiate TEvents
instead of TCriticalSections (and don't do much with same)  the GUI
freezes. In fact I do this in the "OnCreate" Event of the main Form and
(not always but mostly) no child components are shown (but the close button
[x] of the form still works.
> As far as I tried, you cannot use RTLEventWaitFor in main thread,
otherwise the gui will freeze. Don't know what you did...

Of course you can use RTLEventWaitFor (or other blocking functions) inside
the main thread, but then you need to he aware if the consequences: when
the main thread is blocked, then the GUI will be blocked as well, because
the GUI is handled by the main thread only. And a single thread can't do
blocking and running at once ;)

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