关于 获得窗口过程的指针
createwindow(LPVOID(this)) 最后一个参数传递了 this指针


LRESULT CALLBACK MyClass:: CWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch (uMsg)
{
case WM_CREATE:
{

}
case WM_LBUTTONDOWN:

{
CMyClass* pClass; 在这里要获得pClass 指针 如何获得；
}
}

[解决办法]
case WM_CREATE:
{
LPCREATESTRUCT lpcs = (LPCREATESTRUCT)lParam;
MyClass* pclass = (CMyClass*)lpcs->lpCreateParams;
::SetWindowLongPtr(hwnd, GWL_USERDATA, (long)pclass);
}