The framework calls this member function when the user presses the left mouse button while the cursor is within a nonclient area of the CWnd object.
WM_LBUTTONDOWN The WM_LBUTTONDOWN message is posted when the user presses the left mouse button while the cursor is in the client area of a window. If the mouse is not captured, the message is posted to the window beneath the cursor. Otherwise, the message is posted to the window that has captured the mouse. WM_NCLBUTTONDOWN The WM_NCLBUTTONDOWN message is posted when the user presses the left mouse button while the cursor is within the nonclient area of a window. This message is posted to the window that contains the cursor. If a window has captured the mouse, this message is not posted.
The WM_NCLBUTTONDOWN message is posted when the user presses the left mouse button while the cursor is within the nonclient area of a window.
WM_NCLBUTTONDOWN是在窗口非客户区按下鼠标左键
The WM_LBUTTONDOWN message is posted when the user presses the left mouse button while the cursor is in the client area of a window. If the mouse is not captured, the message is posted to the window beneath the cursor. Otherwise, the message is posted to the window that has captured the mouse.
WM_NCLBUTTONDOWN
The WM_NCLBUTTONDOWN message is posted when the user presses the left mouse button while the cursor is within the nonclient area of a window. This message is posted to the window that contains the cursor. If a window has captured the mouse, this message is not posted.