Win32中GDI+应用（四）--- 位图的打开与显示

显示位图，你应该使用GDI+里面的Bitmap类或者Image类，这两个类都提供了方法从硬盘上的一个文件打开文件，创建相应的内存中的位图对象的工作。然后你可以使用Graphics类的DrawImage方法来绘制该位图。
下面的代码初始化GDI+，显示一个打开文件对话框并且创建Bitmap对象，显示位图：

	GdiplusStartupInput input;
	ULONG_PTR gdiPlusToken;
	if(GdiplusStartup(&gdiPlusToken,&input,NULL)!=Ok)
	{
		return -1;
	}

	char fileName[200];
	OPENFILENAME openStruct;
	memset(&openStruct,0,sizeof(OPENFILENAME));
	openStruct.lStructSize=sizeof(OPENFILENAME);
	openStruct.Flags=OFN_EXPLORER;
	openStruct.lpstrFilter="Jpeg files(*.jpg)*.jpg";
	openStruct.lpstrFile=fileName;
	openStruct.nMaxFile=200;
	if(GetOpenFileName(&openStruct))
	{
		imageFileName=fileName;
	}

	HDC hdc=GetDC(hPicWnd);
	if(hdc==NULL)
	{
		MessageBox(NULL,"","",MB_OK);
	}
	Graphics *g=new Graphics(hdc);
	WCHAR tmpFileName[100];
	size_t numOfChars;
	if(/*mbstowcs_s(&numOfChars,tmpFileName,100,fileName,199)*/MultiByteToWideChar(CP_ACP,MB_COMPOSITE,imageFileName.c_str(),200,tmpFileName,100)/*==-1*/)
	{
		MessageBox(NULL,"Error occured in string convertion!","Error!",MB_OK);       
		return wParam;
	}

	HWND hPicWnd；
		RECT rc;
	GetWindowRect(hPicWnd,&rc);

	RectF drawRect(rc.left,rc.top,rc.right-rc.left,rc.bottom-rc.top);
	Bitmap *bmp=new Bitmap(tmpFileName);
	bmpMain=bmp;
	g->DrawImage(bmp,drawRect);
	delete g;

	ReleaseDC(hwnd,hdc);

	GdiplusShutdown(gdiPlusToken);

转载地址:http://www.cppblog.com/dingding/archive/2008/06/27/54796.html