The framework calls this member function when the user double-clicks the left mouse button.
Only windows that have the CS_DBLCLKS WNDCLASS style will receive OnLButtonDblClk calls. This is the default for Microsoft Foundation Class windows. Windows calls OnLButtonDblClk when the user presses, releases, and then presses the left mouse button again within the system's double-click time limit. Double-clicking the left mouse button actually generates four events: WM_LBUTTONDOWN, WM_LBUTTONUP messages, the WM_LBUTTONDBLCLK call, and another WM_LBUTTONUP message when the button is released.
This member function is called by the framework to allow your application to handle a Windows message. The parameters passed to your function reflect the parameters received by the framework when the message was received. If you call the base-class implementation of this function, that implementation will use the parameters originally passed with the message and not the parameters you supply to the function.