You (OP) have a problem everybody seems to run into when doing this at some point.
You call CreateWindow: this->hwnd == NULL
CreateWindow sends WM_NCCreate - you set the window data, this->hwnd still == NULL
CreateWindow sends the other messages it sends - you call Wnd->WndProc, you pass this->hwnd to DefWindowProc but this->hwnd is still NULL
CreateWindow finally returns, after a check only now is this->hwnd set to a valid value
Long story short, you handle who knows how many messages by passing a NULL hwnd to DefWindowProc or to Begin/EndPaint.
The easiest way to fix it is to assign this->hwnd in WM_NCCreate.
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#1adeyblue
Posted 19 October 2012 - 04:07 PM
You have a problem everybody seems to run into when doing this at some point.
You call CreateWindow: this->hwnd == NULL
CreateWindow sends WM_NCCreate - you set the window data, this->hwnd still == NULL
CreateWindow sends the other messages it sends - you call Wnd->WndProc, you pass this->hwnd to DefWindowProc but this->hwnd is still NULL
CreateWindow finally returns, after a check only now is this->hwnd set to a valid value
Long story short, you handle who knows how many messages by passing a NULL hwnd to DefWindowProc or to Begin/EndPaint.
The easiest way to fix it is to assign this->hwnd in WM_NCCreate.
You call CreateWindow: this->hwnd == NULL
CreateWindow sends WM_NCCreate - you set the window data, this->hwnd still == NULL
CreateWindow sends the other messages it sends - you call Wnd->WndProc, you pass this->hwnd to DefWindowProc but this->hwnd is still NULL
CreateWindow finally returns, after a check only now is this->hwnd set to a valid value
Long story short, you handle who knows how many messages by passing a NULL hwnd to DefWindowProc or to Begin/EndPaint.
The easiest way to fix it is to assign this->hwnd in WM_NCCreate.