位图和位块传输(6)画框与会移动的小球

由一个很常用的技巧，这个方法使用"掩码"位图和一些光栅操作，掩码是一个单色位图，它的大小和你要显示的矩形位图大小相同。每个掩码像素对应要显示的位图上的一个像素，要显示出来的像素对应的掩码像素为白色(1)

下面来看看这个例子(来自Windows程序设计第五版圣经)

#include<windows.h>

#include"resource.h"
LRESULT CALLBACK WindowProc(
							HWND hwnd,      // handle to window
							UINT uMsg,      // message identifier
							WPARAM wParam,  // first message parameter
							LPARAM lParam   // second message parameter
							);

int WINAPI WinMain(
				   HINSTANCE hInstance,      // handle to current instance
				   HINSTANCE hPrevInstance,  // handle to previous instance
				   LPSTR lpCmdLine,          // command line
				   int nCmdShow              // show state
				   )
{
	static TCHAR szAppName[]=TEXT("leidemingzi");
	HWND hwnd;
	MSG msg;
	WNDCLASS wndclass;

	wndclass.cbClsExtra=0;
	wndclass.cbWndExtra=0;
	wndclass.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);
	wndclass.hCursor=LoadCursor(NULL,IDC_ARROW);
	wndclass.hIcon=LoadIcon(NULL,IDI_ERROR);
	wndclass.hInstance=hInstance;
	wndclass.lpfnWndProc=WindowProc;
	wndclass.lpszClassName=szAppName;
	wndclass.lpszMenuName=NULL;
	wndclass.style=CS_HREDRAW|CS_VREDRAW;
	

	if(!RegisterClass(&wndclass))
	{

		MessageBox(NULL,TEXT("the program require the windows nt"),TEXT("tips"),MB_ICONERROR);
		return 0;
	}

	hwnd=CreateWindow(
		szAppName,  // registered class name
		TEXT("this is title"), // window name
		WS_OVERLAPPEDWINDOW,        // window style
		CW_USEDEFAULT,                // horizontal position of window
		CW_USEDEFAULT,                // vertical position of window
		CW_USEDEFAULT,           // window width
		CW_USEDEFAULT,          // window height
		NULL,      // handle to parent or owner window
		NULL,          // menu handle or child identifier
		hInstance,  // handle to application instance
		NULL
		// window-creation data
		);

	ShowWindow(hwnd,nCmdShow);
	UpdateWindow(hwnd);

	while(GetMessage(&msg,NULL,0,0))
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}

	return msg.wParam;
}

LRESULT CALLBACK WindowProc(
							HWND hwnd,      // handle to window
							UINT uMsg,      // message identifier
							WPARAM wParam,  // first message parameter
							LPARAM lParam   // second message parameter
							)
{
	static HBITMAP hBitmapImag,hBitmapMask;
	static HINSTANCE hInstance;
	static int cxClient,cyClient,cxBitmap,cyBitmap;
	BITMAP bitmap;
	HDC hdc,hdcMemImag,hdcMemMask;
	int x,y;
	PAINTSTRUCT ps;

	switch (uMsg)
	{
	case WM_CREATE:
		hInstance = ((LPCREATESTRUCT) lParam)->hInstance ;

		// Load the original image and get its size

		hBitmapImag = LoadBitmap (hInstance, MAKEINTRESOURCE(BITMAPID)) ;
		GetObject (hBitmapImag, sizeof (BITMAP), &bitmap) ;
		cxBitmap = bitmap.bmWidth ;
		cyBitmap = bitmap.bmHeight ;

		// Select the original image into a memory DC

		hdcMemImag  = CreateCompatibleDC (NULL) ;
		SelectObject (hdcMemImag, hBitmapImag) ;

		// Create the monochrome mask bitmap and memory DC

		hBitmapMask = CreateBitmap (cxBitmap, cyBitmap, 1, 1, NULL) ;
		hdcMemMask = CreateCompatibleDC (NULL) ;
		SelectObject (hdcMemMask, hBitmapMask) ;

		// Color the mask bitmap black with a white ellipse

		SelectObject (hdcMemMask, GetStockObject (BLACK_BRUSH)) ;
		Rectangle (hdcMemMask, 0, 0, cxBitmap, cyBitmap) ;
		SelectObject (hdcMemMask, GetStockObject (WHITE_BRUSH)) ;
		Ellipse (hdcMemMask, 0, 0, cxBitmap, cyBitmap) ;

		// Mask the original image

		BitBlt (hdcMemImag, 0, 0, cxBitmap, cyBitmap, 
			hdcMemMask, 0, 0, SRCAND) ;

		DeleteDC (hdcMemImag) ;
		DeleteDC (hdcMemMask) ;
		return 0 ;

	case WM_SIZE:
		cxClient = LOWORD (lParam) ;
		cyClient = HIWORD (lParam) ;
		return 0 ;

	case WM_PAINT:
		hdc = BeginPaint (hwnd, &ps) ;

		// Select bitmaps into memory DCs

		hdcMemImag = CreateCompatibleDC (hdc) ;
		SelectObject (hdcMemImag, hBitmapImag) ;

		hdcMemMask = CreateCompatibleDC (hdc) ;
		SelectObject (hdcMemMask, hBitmapMask) ;

		// Center image

		x = (cxClient - cxBitmap) / 2 ;
		y = (cyClient - cyBitmap) / 2 ;

		// Do the bitblts

		BitBlt (hdc, x, y, cxBitmap, cyBitmap, hdcMemMask, 0, 0, 0x220326) ;
		BitBlt (hdc, x, y, cxBitmap, cyBitmap, hdcMemImag, 0, 0, SRCPAINT) ;

		DeleteDC (hdcMemImag) ;
		DeleteDC (hdcMemMask) ;
		EndPaint (hwnd, &ps) ;
		return 0 ;

	case WM_DESTROY:
		DeleteObject (hBitmapImag) ;
		DeleteObject (hBitmapMask) ;
		PostQuitMessage (0) ;
		return 0 ;
	}
	return DefWindowProc (hwnd, uMsg, wParam, lParam) ;
}

下面是会移动的小球

#include <windows.h>
#define ID_TIMER    1
 
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     static TCHAR szAppName[] = TEXT ("Bounce") ;
     HWND         hwnd ;
     MSG          msg ;
     WNDCLASS     wndclass ;

     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 ;
     }
     
     hwnd = CreateWindow (szAppName, TEXT ("Bouncing Ball"),
                          WS_OVERLAPPEDWINDOW,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          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 iMsg, WPARAM wParam, LPARAM lParam)
{
     static HBITMAP hBitmap ;
     static int     cxClient, cyClient, xCenter, yCenter, cxTotal, cyTotal,
                    cxRadius, cyRadius, cxMove, cyMove, xPixel, yPixel ;
     HBRUSH         hBrush ;
     HDC            hdc, hdcMem ;
     int            iScale ;
     
     switch (iMsg)
     {
     case WM_CREATE:
          hdc = GetDC (hwnd) ;
          xPixel = GetDeviceCaps (hdc, ASPECTX) ;
          yPixel = GetDeviceCaps (hdc, ASPECTY) ;
          ReleaseDC (hwnd, hdc) ;
          
          SetTimer (hwnd, ID_TIMER, 50, NULL) ;
          return 0 ;
          
     case WM_SIZE:
          xCenter = (cxClient = LOWORD (lParam)) / 2 ;
          yCenter = (cyClient = HIWORD (lParam)) / 2 ;
          
          iScale = min (cxClient * xPixel, cyClient * yPixel) / 16 ;
          
          cxRadius = iScale / xPixel ;
          cyRadius = iScale / yPixel ;
          
          cxMove = max (1, cxRadius / 2) ;
          cyMove = max (1, cyRadius / 2) ;
          
          cxTotal = 2 * (cxRadius + cxMove) ;
          cyTotal = 2 * (cyRadius + cyMove) ;
          
          if (hBitmap)
               DeleteObject (hBitmap) ;
          
          hdc = GetDC (hwnd) ;
          hdcMem = CreateCompatibleDC (hdc) ;
          hBitmap = CreateCompatibleBitmap (hdc, cxTotal, cyTotal) ;
          ReleaseDC (hwnd, hdc) ;
          
          SelectObject (hdcMem, hBitmap) ;
          Rectangle (hdcMem, -1, -1, cxTotal + 1, cyTotal + 1) ;
          
          hBrush = CreateHatchBrush (HS_DIAGCROSS, 0L) ;
          SelectObject (hdcMem, hBrush) ;
          SetBkColor (hdcMem, RGB (255, 0, 255)) ;
          Ellipse (hdcMem, cxMove, cyMove, cxTotal - cxMove, cyTotal - cyMove) ;
          DeleteDC (hdcMem) ;
          DeleteObject (hBrush) ;
          return 0 ;
          
     case WM_TIMER:
          if (!hBitmap)
               break ;
          
          hdc = GetDC (hwnd) ;
          hdcMem = CreateCompatibleDC (hdc) ;
          SelectObject (hdcMem, hBitmap) ;
          
          BitBlt (hdc, xCenter - cxTotal / 2,
                       yCenter - cyTotal / 2, cxTotal, cyTotal,
                  hdcMem, 0, 0, SRCCOPY) ;
          
          ReleaseDC (hwnd, hdc) ;
          DeleteDC (hdcMem) ;
          
          xCenter += cxMove ;
          yCenter += cyMove ;
          
          if ((xCenter + cxRadius >= cxClient) || (xCenter - cxRadius <= 0))
               cxMove = -cxMove ;
          
          if ((yCenter + cyRadius >= cyClient) || (yCenter - cyRadius <= 0))
               cyMove = -cyMove ;
          
          return 0 ;
          
     case WM_DESTROY:
          if (hBitmap)
               DeleteObject (hBitmap) ;
          
          KillTimer (hwnd, ID_TIMER) ;
          PostQuitMessage (0) ;
          return 0 ;
     }
     return DefWindowProc (hwnd, iMsg, wParam, lParam) ;
}

闪屏：

#include <windows.h>

#define NUM 300

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     static int iKeep [NUM][4] ;
     HDC        hdcScr, hdcMem ;
     int        cx, cy ;
     HBITMAP    hBitmap ;
     HWND       hwnd ;
     int        i, j, x1, y1, x2, y2 ;

     if (LockWindowUpdate (hwnd = GetDesktopWindow ()))
     {
          hdcScr  = GetDCEx (hwnd, NULL, DCX_CACHE | DCX_LOCKWINDOWUPDATE) ;
          hdcMem  = CreateCompatibleDC (hdcScr) ;
          cx      = GetSystemMetrics (SM_CXSCREEN) / 10 ;
          cy      = GetSystemMetrics (SM_CYSCREEN) / 10 ;
          hBitmap = CreateCompatibleBitmap (hdcScr, cx, cy) ;
         
          SelectObject (hdcMem, hBitmap) ;

          srand ((int) GetCurrentTime ()) ;
          
          for (i = 0 ; i < 2   ; i++)
          for (j = 0 ; j < NUM ; j++)
          {
               if (i == 0)
               {
                    iKeep [j] [0] = x1 = cx * (rand () % 10) ;
                    iKeep [j] [1] = y1 = cy * (rand () % 10) ;
                    iKeep [j] [2] = x2 = cx * (rand () % 10) ;
                    iKeep [j] [3] = y2 = cy * (rand () % 10) ;
               }
               else
               {
                    x1 = iKeep [NUM - 1 - j] [0] ;
                    y1 = iKeep [NUM - 1 - j] [1] ;
                    x2 = iKeep [NUM - 1 - j] [2] ;
                    y2 = iKeep [NUM - 1 - j] [3] ;
               }
               BitBlt (hdcMem,  0,  0, cx, cy, hdcScr, x1, y1, SRCCOPY) ;
               BitBlt (hdcScr, x1, y1, cx, cy, hdcScr, x2, y2, SRCCOPY) ;
               BitBlt (hdcScr, x2, y2, cx, cy, hdcMem,  0,  0, SRCCOPY) ;
                    
               Sleep (10) ;
          }
               
          DeleteDC (hdcMem) ;
          ReleaseDC (hwnd, hdcScr) ;
          DeleteObject (hBitmap) ;
             
          LockWindowUpdate (NULL) ;
     }
     return FALSE ;
}

自个试验去

因为慢着学习别的东西，没有太多时间来写自己的理解，匆忙写点笔记。