位图和位块传输(3)之加载位图资源

Windows提供了两个能在位图被创建后取得和设置位图像素的函数

SetBitmapBits(hBitmap,cBytes,&bits);GetBitmapBits(hBitmap,cBytes,&bits);

 

使用GDI位图对象时，需要用到内存设备环境，要创建一个内存设备环境，必须有一个对应真实设备的环境句柄。假设句柄是hdc，则可以像下面这样创建一个内存设备环境

hdcMem=CreateCompatibleDC(hdc);

它和特定的真实设备"兼容"。

加载位图资源，LoadBitMap和LoadIcon和LoadCursor函数的语法一样

hBitmap=LoadBitmap(hInstance,szBitmapName);//知道位图ID用：hBitmap=LoadBitmap(hInstance,MAKEINTRESOURCE(BITMAPID));

下面是一个完整的例子

编好CPP文件，创建资源位图：

#include<windows.h>#include"resource.h"LRESULT CALLBACK WindowProc(HWND hwnd,      // handle to windowUINT uMsg,      // message identifierWPARAM wParam,  // first message parameterLPARAM 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 window nt"),TEXT("tips"),MB_ICONERROR);return 0;}hwnd=CreateWindow(szAppName,  // registered class nameTEXT("this is title"), // window nameWS_OVERLAPPEDWINDOW,        // window styleCW_USEDEFAULT,                // horizontal position of windowCW_USEDEFAULT,                // vertical position of windowCW_USEDEFAULT,           // window widthCW_USEDEFAULT,          // window heightNULL,      // handle to parent or owner windowNULL,          // menu handle or child identifierhInstance,  // handle to application instanceNULL// 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 windowUINT uMsg,      // message identifierWPARAM wParam,  // first message parameterLPARAM lParam   // second message parameter){static HBITMAP hBitmap;static int cxClient,cyClient,cxSource,cySource;BITMAP bitmap;HINSTANCE hInstance;HDC hdc,hdcMem;int x,y;PAINTSTRUCT ps;switch(uMsg){case WM_CREATE:hInstance=((LPCREATESTRUCT)lParam)->hInstance;hBitmap=LoadBitmap(hInstance,MAKEINTRESOURCE(BITMAPID));GetObject(hBitmap,sizeof(BITMAP),&bitmap);cxSource=bitmap.bmWidth;cySource=bitmap.bmHeight;return 0;case WM_SIZE:cxClient=LOWORD(lParam);cyClient=HIWORD(lParam);return 0;case WM_PAINT:hdc=BeginPaint(hwnd,&ps);hdcMem=CreateCompatibleDC(hdc);SelectObject(hdcMem,hBitmap);for(y=0;y<cyClient;y+=cySource)for(x=0;x<cxClient;x+=cxSource)BitBlt(hdc,x,y,cxSource,cySource,hdcMem,0,0,SRCCOPY);DeleteDC(hdcMem);EndPaint(hwnd,&ps);return 0;case WM_DESTROY:PostQuitMessage(0);return 0;}return DefWindowProc(hwnd,uMsg,wParam,lParam);}

效果就是一副墙：

 

下面代码可以达到同样的效果：

#include<windows.h>LRESULT CALLBACK WindowProc(HWND hwnd,      // handle to windowUINT uMsg,      // message identifierWPARAM wParam,  // first message parameterLPARAM 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 window nt"),TEXT("tips"),MB_ICONERROR);return 0;}hwnd=CreateWindow(szAppName,  // registered class nameTEXT("this is title"), // window nameWS_OVERLAPPEDWINDOW,        // window styleCW_USEDEFAULT,                // horizontal position of windowCW_USEDEFAULT,                // vertical position of windowCW_USEDEFAULT,           // window widthCW_USEDEFAULT,          // window heightNULL,      // handle to parent or owner windowNULL,          // menu handle or child identifierhInstance,  // handle to application instanceNULL// 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 windowUINT uMsg,      // message identifierWPARAM wParam,  // first message parameterLPARAM lParam   // second message parameter){static BITMAP bitmap={0,8,8,2,1,1};static BYTE bits[8][2]={0xFF,0,0x0C,0,0x0C,0,0x0C,0,0xFF,0,0xC0,0,0xC0,0,0xC0,0};static HBITMAP hBitmap;static int cxClient,cyClient,cxSource,cySource;HDC hdc,hdcMem;int x,y;PAINTSTRUCT ps;switch(uMsg){case WM_CREATE:bitmap.bmBits=bits;hBitmap=CreateBitmapIndirect(&bitmap);cxSource=bitmap.bmWidth;cySource=bitmap.bmHeight;return 0;case WM_SIZE:cxClient=LOWORD(lParam);cyClient=HIWORD(lParam);return 0;case WM_PAINT:hdc=BeginPaint(hwnd,&ps);hdcMem=CreateCompatibleDC(hdc);SelectObject(hdcMem,hBitmap);for(y=0;y<cyClient;y+=cySource)for(x=0;x<cxClient;x+=cxSource)BitBlt(hdc,x,y,cxSource,cySource,hdcMem,0,0,SRCCOPY);DeleteDC(hdcMem);EndPaint(hwnd,&ps);return 0;case WM_DESTROY:PostQuitMessage(0);return 0;}return DefWindowProc(hwnd,uMsg,wParam,lParam);}