求助!关于图像显示的问题 打印预览中用StretchDIBits显示bmp图像但显示速度非常慢(用的是MM_TWIPS映射模式),显示一幅大约3 * 6 cm的图片耗时差不多要一秒多,但在其他地方用同样的函数显示却非常快。不只是何原因,还望高手指点! 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 用 GDIplus 吧,又快又簡單。 #define HIMETRIC_INCH 2540LPPICTURE gpPicture;void ShowPicture(CDC* pDC,CString m_strBRoute,int x,int y,int width,int height){ HANDLE hFile = CreateFile(m_strBRoute, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL); _ASSERTE(INVALID_HANDLE_VALUE != hFile); // 取得文件大小 DWORD dwFileSize = GetFileSize(hFile, NULL); _ASSERTE(-1 != dwFileSize); LPVOID pvData = NULL; //根据文件大小分配内存 HGLOBAL hGlobal = GlobalAlloc(GMEM_MOVEABLE, dwFileSize); _ASSERTE(NULL != hGlobal); pvData = GlobalLock(hGlobal); _ASSERTE(NULL != pvData); DWORD dwBytesRead = 0; //读取文件并存入全局内存 BOOL bRead = ReadFile(hFile, pvData, dwFileSize, &dwBytesRead, NULL); _ASSERTE(FALSE != bRead); GlobalUnlock(hGlobal); CloseHandle(hFile); LPSTREAM pstm = NULL; // 通过全局内存创建 IStream* 的指针 HRESULT hr = CreateStreamOnHGlobal(hGlobal, TRUE, &pstm); _ASSERTE(SUCCEEDED(hr) && pstm); //通过图形文件创建IPicture 对象 if (gpPicture) gpPicture->Release(); hr = OleLoadPicture(pstm, dwFileSize, FALSE, IID_IPicture, (LPVOID *)&gpPicture); _ASSERTE(SUCCEEDED(hr) && gpPicture); pstm->Release(); HDC hdc; hdc=pDC->GetSafeHdc(); if (gpPicture) { // 取得图片的宽和高 long hmWidth; long hmHeight; gpPicture->get_Width(&hmWidth); gpPicture->get_Height(&hmHeight); //宽高转换为象素 int nWidth = MulDiv(hmWidth, GetDeviceCaps(hdc, LOGPIXELSX), HIMETRIC_INCH); int nHeight = MulDiv(hmHeight, GetDeviceCaps(hdc, LOGPIXELSY), HIMETRIC_INCH); RECT rc; GetClientRect(&rc);/*取得客户区*/ gpPicture->Render(hdc, x,y, (int)height*hmWidth/hmHeight,height, 0, hmHeight, hmWidth, -hmHeight, &rc); /*显示图片*/ }} 求助关于属性页的相关问题 调节显示器亮度!!! 关于API 创建菜单 无法替换回调函数的问题 我想对手写笔进行编程,哪能找到相应的API或者SDK? 指针对象为0xdddddddd表时什么意思,但我访问的时候又会出错? 好的电影网站,免费 如何判断当前用户的计算机是否在网上? 问一个关与得到对话框上控件位址的方法!谢谢! COMMTIMEOUTS读设置延时0,ReadFile函数重叠读取时,wait等待500毫秒对吗??? 在MFC中使用SQL语句 pdf文件用什么程序打开? 再线等待。。。打印程序
LPPICTURE gpPicture;
void ShowPicture(CDC* pDC,CString m_strBRoute,int x,int y,int width,int height)
{
HANDLE hFile = CreateFile(m_strBRoute, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);
_ASSERTE(INVALID_HANDLE_VALUE != hFile); // 取得文件大小
DWORD dwFileSize = GetFileSize(hFile, NULL);
_ASSERTE(-1 != dwFileSize);
LPVOID pvData = NULL;
//根据文件大小分配内存
HGLOBAL hGlobal = GlobalAlloc(GMEM_MOVEABLE, dwFileSize);
_ASSERTE(NULL != hGlobal);
pvData = GlobalLock(hGlobal);
_ASSERTE(NULL != pvData);
DWORD dwBytesRead = 0;
//读取文件并存入全局内存
BOOL bRead = ReadFile(hFile, pvData, dwFileSize, &dwBytesRead, NULL);
_ASSERTE(FALSE != bRead);
GlobalUnlock(hGlobal);
CloseHandle(hFile);
LPSTREAM pstm = NULL;
// 通过全局内存创建 IStream* 的指针
HRESULT hr = CreateStreamOnHGlobal(hGlobal, TRUE, &pstm);
_ASSERTE(SUCCEEDED(hr) && pstm);
//通过图形文件创建IPicture 对象
if (gpPicture)
gpPicture->Release();
hr = OleLoadPicture(pstm, dwFileSize, FALSE, IID_IPicture, (LPVOID *)&gpPicture);
_ASSERTE(SUCCEEDED(hr) && gpPicture);
pstm->Release();
HDC hdc;
hdc=pDC->GetSafeHdc();
if (gpPicture)
{
// 取得图片的宽和高
long hmWidth;
long hmHeight;
gpPicture->get_Width(&hmWidth);
gpPicture->get_Height(&hmHeight);
//宽高转换为象素
int nWidth = MulDiv(hmWidth, GetDeviceCaps(hdc, LOGPIXELSX), HIMETRIC_INCH);
int nHeight = MulDiv(hmHeight, GetDeviceCaps(hdc, LOGPIXELSY), HIMETRIC_INCH);
RECT rc;
GetClientRect(&rc);/*取得客户区*/
gpPicture->Render(hdc, x,y, (int)height*hmWidth/hmHeight,height, 0, hmHeight, hmWidth, -hmHeight, &rc);
/*显示图片*/
}}