The WM_HSCROLLCLIPBOARD message is sent to the clipboard owner by a clipboard viewer window. This occurs when the clipboard contains data in the CF_OWNERDISPLAY format and an event occurs in the clipboard viewer's horizontal scroll bar. The owner should scroll the clipboard image and update the scroll bar values.
WM_HSCROLLCLIPBOARD
hwndViewer = (HWND) wParam; // handle of clipboard viewer window
nScrollCode = (int) LOWORD(lParam); // scroll bar code
nPos = (int) HIWORD(lParam); // scroll box position
Parameters
hwndViewer
Value of wParam. Identifies the clipboard viewer window.
nScrollCode
Value of the low-order word of lParam. Specifies a scroll bar event. This parameter can be one of the following values:
| Value | Meaning |
| SB_BOTTOM | Scroll to lower right. |
| SB_ENDSCROLL | End scroll. |
| SB_LINEDOWN | Scroll one line down. |
| SB_LINEUP | Scroll one line up. |
| SB_PAGEDOWN | Scroll one page down. |
| SB_PAGEUP | Scroll one page up. |
| SB_THUMBPOSITION | Scroll to absolute position. The current position is specified by the nPos parameter. |
| SB_TOP | Scroll to upper left. |
nPos
Value of the high-order word of lParam. Specifies the current position of the scroll box if the nScrollCode parameter is SB_THUMBPOSITION; otherwise, the nPos parameter is not used.
Return Values
If an application processes this message, it should return zero.
Remarks
The clipboard owner can use the ScrollWindow function to scroll the image in the clipboard viewer window and invalidate the appropriate region.
See Also