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 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 window 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 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 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 window 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 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);
}