问题
In my application I run wglGetCurrentDC() and wglGetCurrentContext() from onThread function
(this function should be called as declared here - EVT_THREAD(wxID_ANY,MyCanvas::onThread))
and I get NULL in both cases. When I run it not from onThread it is ok…
What is work around in order to solve the problem – (I have to run them when getting event from the thread!)
As Alex suggested I changed to wxPostEvent to redirect the event to main thread, which catches the event in its onThread function.In this onThread function I have wglGetCurrentDC() and wglGetCurrentContext() calls ...They still return null.Please explain me what I am doing wrong. And how to solve he problem.
回答1:
Maybe I'm misunderstanding, but should you not be using wxGLCanvas and wxGLContext rather than the windows-specific code? At the very least it's probably more compatible with other wxWidget code.
Anyway, from the wglGetCurrentDC documentation, the function returns NULL if a DC for the current window doesn't exist. This suggests that either the context was destroyed somehow or you're not calling it from the window you think you're calling it from (perhaps because of your threading?). I would reiterate what Alex said; don't call UI code from any thread besides the main one.
If you could post some code showing how you're returning from the thread it might help identify the problem. It seems likely that you're doing UI stuff from the thread and just not realizing it. (Hard to tell without seeing any code, though.)
回答2:
Don't touch any UI-related stuff from a worker thread. This is general requirement for all UI frameworks. Use wxPostEvent to redirect a work to the main application thread.
来源：https://stackoverflow.com/questions/6890169/wxwidgets-and-threads