Let's take a look at the WM_VSCROLL message first:
WM_VSCROLL is defined in the header file. Defined as: #define WM_VSCROLL 0x0115. When a scrolling event occurs in the standard vertical scroll of the window, a WM_VSCROLL message will be generated in the message queue of our window application.
parameter
wParam
SB_PAGEDOWN Scroll down a page
SB_LINEDOWN Scroll down a line
SB_PAGEUP Scroll up a page
SB_LINEUP Scroll up a line
SB_TOP Scroll to the top
SB_BOTTOM Scroll to the bottom
SB_THUMBPOSITION The user has dragged the scroll box (slider) and released the mouse button. HIWORD Indicates the position of the scroll box when the drag operation is over.
SB_THUMBTRACK The user is dragging the scroll box. This email is sent repeatedly until the user releases the mouse button. HIWORD Indicates where the scroll box has been dragged.
lParam
If the lParam parameter is equal to 0, it means it is a window scrollbar; if it is equal to the scrollbar window handle, it means it is a scrollbar control.
Return value
If the application processes the message, it should return zero.
See how to write Yi Language:
Send message integer (List handle [1], 277, 1, 0)
Parameter analysis:
List handle[1]: window handle, I use the window enumeration of the exquisite template_sub-window to get
277: Information number;
1: It should be
SB_PAGEDOWN Scroll down a page
SB_LINEDOWN Scroll down a line