Win32的滚动条实例

//ScrollBar02(滚动条实例2) #include<windows.h> #include"resource.h" LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) { static TCHAR szAppName[] = TEXT("ScrollBar02"); HWND hwnd; MSG msg; WNDCLASS wndclass; int cxScreen, cyScreen; wndclass.style = CS_HREDRAW | CS_VREDRAW; wndclass.lpfnWndProc = WndProc; wndclass.cbClsExtra = 0; wndclass.cbWndExtra = 0; wndclass.hInstance = hInstance; wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION); wndclass.hCursor = LoadCursor(NULL, IDC_ARROW); wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH); wndclass.lpszMenuName = NULL; wndclass.lpszClassName = szAppName; if(!RegisterClass(&wndclass)) { MessageBox(NULL, TEXT("This program requires Windows NT!"), szAppName, MB_ICONERROR); return 0; } cxScreen = GetSystemMetrics(SM_CXSCREEN); cyScreen = GetSystemMetrics(SM_CYSCREEN); hwnd = CreateWindow(szAppName, TEXT("ScrollBar02 Demo"), WS_OVERLAPPEDWINDOW | WS_VSCROLL | WS_HSCROLL,//添加水平、垂直滚动条 cxScreen * 3 / 10,//居中显示 cyScreen / 4, cxScreen * 2 / 5, cyScreen / 2, NULL, NULL, hInstance, NULL); ShowWindow(hwnd, iCmdShow); UpdateWindow(hwnd); while(GetMessage(&msg, NULL, 0, 0)) { TranslateMessage(&msg); DispatchMessage(&msg); } return msg.wParam; } LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) { //依次是 位图的长宽 客户区的大小 static int cxBitmap, cyBitmap, cxClient, cyClient; static HBITMAP hBitmap; int iHorzPos, iVertPos;//水平滚动条位置 垂直滚动条位置 BITMAP bitmap; HINSTANCE hInstance; HDC hdc, hdcMem; PAINTSTRUCT ps; SCROLLINFO si; switch(message) { case WM_CREATE: //加载位图 hInstance = ((LPCREATESTRUCT)lParam)->hInstance; hBitmap = LoadBitmap(hInstance, MAKEINTRESOURCE(IDB_BITMAP1)); GetObject(hBitmap, sizeof(BITMAP), &bitmap); cxBitmap = bitmap.bmWidth; cyBitmap = bitmap.bmHeight; return 0 ; case WM_SIZE: cxClient = LOWORD(lParam); cyClient = HIWORD(lParam); //设定垂直滚动条范围和页面大小 si.cbSize = sizeof(si); si.fMask = SIF_RANGE | SIF_PAGE; si.nMin = 0; si.nMax = cyBitmap; si.nPage = cyClient; SetScrollInfo(hwnd, SB_VERT, &si, TRUE); //设定水平滚动条范围和页面大小 si.cbSize = sizeof(si); si.fMask = SIF_RANGE | SIF_PAGE; si.nMin = 0; si.nMax = cxBitmap; si.nPage = cxClient; SetScrollInfo(hwnd, SB_HORZ, &si, TRUE); return 0; //处理垂直滚动条消息 case WM_VSCROLL: si.cbSize = sizeof(si); si.fMask = SIF_ALL; GetScrollInfo(hwnd, SB_VERT, &si); iVertPos = si.nPos; switch(LOWORD(wParam)) { case SB_TOP: //置顶(先按下Shift键不放，然后点击滚动条方块上侧区域就能置顶) si.nPos = si.nMin ; break ; case SB_BOTTOM://置底(同置顶) si.nPos = si.nMax ; break ; case SB_LINEUP: si.nPos -= 10 ;//每一行滚动10个像素 break ; case SB_LINEDOWN: si.nPos += 10 ; break ; case SB_PAGEUP://翻页就是一个客户区大小 si.nPos -= cyClient ; break ; case SB_PAGEDOWN: si.nPos += cyClient ; break ; case SB_THUMBTRACK: si.nPos = HIWORD (wParam) ; break ; default : break ; } si.fMask = SIF_POS; SetScrollInfo(hwnd, SB_VERT, &si, TRUE); GetScrollInfo(hwnd, SB_VERT, &si); if(iVertPos != si.nPos) { //这里InvalidateRect、ScrollWindow，效果相同 InvalidateRect(hwnd, NULL, FALSE); //ScrollWindow(hwnd, 0, iVertPos - si.nPos, NULL, NULL); } return 0; //处理水平滚动条(和垂直的类似) case WM_HSCROLL: si.cbSize = sizeof(si); si.fMask = SIF_ALL; GetScrollInfo(hwnd, SB_HORZ, &si); iHorzPos = si.nPos; switch(LOWORD(wParam)) { case SB_LINELEFT: si.nPos -= 10 ; break ; case SB_LINERIGHT: si.nPos += 10 ; break ; case SB_PAGELEFT: si.nPos -= cxClient ; break ; case SB_PAGERIGHT: si.nPos += cxClient ; break ; case SB_THUMBTRACK: si.nPos = HIWORD (wParam) ; break ; default : break ; } si.fMask = SIF_POS; SetScrollInfo(hwnd, SB_HORZ, &si, TRUE); GetScrollInfo(hwnd, SB_HORZ, &si); if(iHorzPos != si.nPos) { InvalidateRect(hwnd, NULL, FALSE); //ScrollWindow(hwnd, iHorzPos - si.nPos, 0, NULL, NULL); } return 0; case WM_PAINT: //Sleep(1000); hdc = BeginPaint(hwnd, &ps); si.cbSize = sizeof (si) ; si.fMask = SIF_POS ; GetScrollInfo (hwnd, SB_VERT, &si) ; iVertPos = si.nPos ; // Get horizontal scroll bar position GetScrollInfo (hwnd, SB_HORZ, &si) ; iHorzPos = si.nPos ; hdcMem = CreateCompatibleDC(hdc); SelectObject(hdcMem, hBitmap); /* 这里有个难点:用iHscrollPos和iVscrollPos的相反数作为图片显示的坐标. 因为我们要保证滚动条的位置这个参数要是一个正数 , 这样显示才能正常, 又由于滚动条滚动的方向和图片走向是相反的 , 所以当然要去相反数了 */ BitBlt(hdc, -iHorzPos, -iVertPos, cxBitmap, cyBitmap, hdcMem, 0, 0, SRCCOPY); DeleteDC(hdcMem); EndPaint(hwnd, &ps); return 0; case WM_DESTROY: DeleteObject(hBitmap);//注意释放资源占的内存 PostQuitMessage(0); return 0; } return DefWindowProc(hwnd, message, wParam, lParam); }