平時在處理滾動條程序時,總覺得代碼很長,敲得手都累了,今天在試了試,也還行。
總結起來大致有三步:
- 設置滾動條的範圍之類的基本信息,如可以再WM_SIZE消息中處理
- 響應滾動條消息並設置變化中的滾動條
- 更新界面變化
看個實例代碼,當然,代碼還是很長,可以想辦法幫封裝一下:
case WM_SIZE:
cx = LOWORD(lp);
cy = HIWORD(lp);
si.cbSize = sizeof(SCROLLINFO);
si.fMask = SIF_RANGE | SIF_PAGE;
si.nMin = 0;
si.nMax = NUMLINES - 1;
si.nPage = cy / cyChar;
SetScrollInfo( hwnd, SB_VERT, &si, TRUE );
si.fMask = SIF_RANGE | SIF_PAGE;
si.nMin = 0;
si.nMax = 2 + iMaxWidth / cxChar;
si.nPage = cx / cxChar;
SetScrollInfo( hwnd, SB_HORZ, &si, TRUE );
return 0;
case WM_VSCROLL:
si.cbSize = sizeof(si);
si.fMask = SIF_ALL;
GetScrollInfo( hwnd, SB_VERT, &si );
iVertPos = si.nPos;
switch(LOWORD(wp))
{
case SB_TOP:
si.nPos = si.nMin;
break;
case SB_BOTTOM:
si.nPos = si.nMax;
break;
case SB_LINEUP:
si.nPos -= 1;
break;
case SB_LINEDOWN:
si.nPos += 1;
break;
case SB_PAGEUP:
si.nPos -= si.nPage;
break;
case SB_PAGEDOWN:
si.nPos += si.nPage;
break;
case SB_THUMBTRACK:
si.nPos = si.nTrackPos;
break;
default:
break;
}
si.fMask = SIF_POS;
SetScrollInfo( hwnd, SB_VERT, &si, TRUE );
GetScrollInfo( hwnd, SB_VERT, &si);
if ( si.nPos != iVertPos )
{
ScrollWindow( hwnd, 0, cxChar * (iVertPos - si.nPos), NULL, NULL );
UpdateWindow( hwnd );
}
return 0;
case WM_HSCROLL:
si.cbSize = sizeof(si);
si.fMask = SIF_ALL;
GetScrollInfo( hwnd, SB_HORZ, &si );
iHorPos = si.nPos;
switch(LOWORD(wp))
{
case SB_LINELEFT:
si.nPos -= 1;
break;
case SB_LINERIGHT:
si.nPos += 1;
break;
case SB_PAGELEFT:
si.nPos -= si.nPage;
break;
case SB_PAGERIGHT:
si.nPos += si.nPage;
break;
case SB_THUMBPOSITION:
si.nPos = si.nTrackPos;
break;
default:
break;
}
si.fMask = SIF_POS;
SetScrollInfo( hwnd, SB_HORZ, &si, TRUE );
GetScrollInfo( hwnd, SB_HORZ, &si);
if ( si.nPos != iHorPos )
{
ScrollWindow( hwnd, 0, cxChar * (iHorPos - si.nPos), NULL, NULL );
UpdateWindow( hwnd );
}
return 0;