|Subject:||Creating a static control for another another thread causes 50% CPU on hovering and 'lockup' on clicking ?|
|Posted by:||R.Wieser (addre…@not.available)|
|Date:||Thu, 24 Jan 2019|
When I hover the mouse over a static control the CPU jumps to 50% (according
to the task manager). When I click the static(!) control the program seems
to block until I cover the window the control is in.
Not a problem (I rewrote the code so the control is created in the windows
thread), but a request for an explanation. You see, the thing is that it
happens for a static control - which should not respond to the mouse in any
way ! - but not for a button.
The circumstances are like this:
I've created a thread which in turn registers a class and creates a window
from it. The program creating the thread receives the handle to the created
window, and uses it to create the above static control and a button. Both
appear on the window.
All goes fine when click the button and/or send messages to that window.
But as soon as my mouse is ontop of the static control things start to go
What might be causing it ?
I've googled the problem and although the consensus is to "never create
cross-thread controls!" I do not see any explanation to the why of it or
what is causing the CPU load / lockup - and I'm curious. :-)