请问,在VC中,怎么取JPG的高度和宽度啊?
解决方案 »
- 《代码揭秘》(左飞) 这本书竟然要买 ¥56
- 窗口的关闭按钮失效
- C++如何通过URL获得网页信息呀?求多种
- 全局hook无法启动线程!
- 如何实现无标题栏的对话框自由拖动?
- 如何派生CObject类的派生类
- 请问如何在一个对话框里同时显示多幅图片?
- 一个图形缩放打印的问题,请高手指点一二。谢谢谢....!!!!!
- CreateFileMapping之后,如何Release 这个Mapping , 并重新CreateFileMapping(大小不同)
- 能否通过代理服务器访问在代理服务器后面HTTP服务器
- 问一个关于自定义消息简单的问题
- VS2005创建的ATL service(exe)中如何使用MFC
CImage cimage;
hVzCdbRet = cimage.Load(bstrFilePath); if (SUCCEEDED(hVzCdbRet))
{
// Get height and width of JPEG Photo
int iHeight = cimage.GetHeight();
int iWidth = cimage.GetWidth();
}
CImage这个类MFC里面没有吧,不会又要到网上下载吧?
vc6可以使用gdi+的Image,它也有GetWidth和GetHeight.
那GDI+的image要怎么使用啊?
是不是也要下载GDI+的库才可以啊?
IImage *PS;
看能不能用,我在WINCE中用这个加载图片
http://www.codeproject.com/bitmap/CXImage.asp
#ifndef _CGPPICTURE
#define _CGPPICTURE#pragma once
#include <atlbase.h>//////////////////////////////////////////
// GPPictureclass CGPPicture
{
public:
CGPPicture();
~CGPPicture(); BOOL Load(UINT nIDRes);
BOOL Load(LPCTSTR pszPathName);
BOOL Load(CFile& file);
BOOL Load(CArchive& ar);
BOOL Load(IStream* pstm);///////////////////////////////////////////////////////////////////////
BOOL Render(CDC* pDC, CRect rc=CRect(0,0,0,0), LPCRECT prcMFBounds=NULL) const; CSize GetImageSize(CDC* pDC=NULL) const;
void GetHIMETRICSize(OLE_XSIZE_HIMETRIC& cx, OLE_YSIZE_HIMETRIC& cy) const
{
cx = cy = 0;
const_cast<CGPPicture*>(this)->_hResult = _spIPicture->get_Width(&cx);
ASSERT(SUCCEEDED(_hResult));
const_cast<CGPPicture*>(this)->_hResult = _spIPicture->get_Height(&cy);
ASSERT(SUCCEEDED(_hResult));
}
void Free()
{
if (_spIPicture)
{
_spIPicture.Release();
}
}////////////////////////////////////////////////////////////////////// operator IPicture*() {return _spIPicture;}protected:
CComQIPtr<IPicture> _spIPicture; //ATL的图片指针
HRESULT _hResult; //用于储存操作结果的句柄
};#endif
实现文件#include "StdAfx.h"
#include "GPPicture.h"#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif////////////////////////////////////////////////////////////////
// CGPPicture implementation
//CGPPicture::CGPPicture()
{
}CGPPicture::~CGPPicture()
{
}//////////////////
// Load from resource. Looks for "IMAGE" type.
//
BOOL CGPPicture::Load(UINT nIDRes)
{
// find resource in resource file
HINSTANCE hInst = AfxGetResourceHandle();
HRSRC hRsrc = ::FindResource(hInst, MAKEINTRESOURCE(nIDRes), "JPG"); // type
if (!hRsrc)
return FALSE; // load resource into memory
DWORD len = SizeofResource(hInst, hRsrc);
BYTE* lpRsrc = (BYTE*)LoadResource(hInst, hRsrc);
if (!lpRsrc)
return FALSE; // create memory file and load it
CMemFile file(lpRsrc, len);
BOOL bRet = Load(file);
FreeResource(hRsrc); return bRet;
}//////////////////
// Load from path name.
//
BOOL CGPPicture::Load(LPCTSTR pszPathName)
{
CFile file;
if (!file.Open(pszPathName, CFile::modeRead|CFile::shareDenyWrite))
return FALSE;
BOOL bRet = Load(file);
file.Close();
return bRet;
}//////////////////
// Load from CFile
//
BOOL CGPPicture::Load(CFile& file)
{
CArchive ar(&file, CArchive::load | CArchive::bNoFlushOnDelete);
return Load(ar);
}//////////////////
// Load from archive--create stream and load from stream.
//
BOOL CGPPicture::Load(CArchive& ar)
{
CArchiveStream arcstream(&ar);
return Load((IStream*)&arcstream);
}//////////////////
// Load from stream (IStream). This is the one that really does it: call
// OleLoadPicture to do the work.
//
BOOL CGPPicture::Load(IStream* pstm)
{
Free();
HRESULT hr = OleLoadPicture(pstm, 0, FALSE,
IID_IPicture, (void**)&_spIPicture);
ASSERT(SUCCEEDED(hr) && _spIPicture);
return TRUE;
}//////////////////
// Render to device context. Covert to HIMETRIC for IPicture.
//
BOOL CGPPicture::Render(CDC* pDC, CRect rc, LPCRECT prcMFBounds) const
{
ASSERT(pDC); if (rc.IsRectNull()) {
CSize sz = GetImageSize(pDC);
rc.right = sz.cx;
rc.bottom = sz.cy;
}
long hmWidth,hmHeight; // HIMETRIC units
GetHIMETRICSize(hmWidth, hmHeight);
_spIPicture->Render(*pDC, rc.left, rc.top, rc.Width(), rc.Height(),
0, hmHeight, hmWidth, -hmHeight, prcMFBounds); return TRUE;
}//////////////////
// Get image size in pixels. Converts from HIMETRIC to device coords.
//
CSize CGPPicture::GetImageSize(CDC* pDC) const
{
if (!_spIPicture)
return CSize(0,0);
LONG hmWidth, hmHeight; // HIMETRIC units
_spIPicture->get_Width(&hmWidth);
_spIPicture->get_Height(&hmHeight);
CSize sz(hmWidth,hmHeight); if (pDC==NULL)
{
CWindowDC dc(NULL);
dc.HIMETRICtoDP(&sz); // convert to pixels
}else
{
pDC->HIMETRICtoDP(&sz);
} return sz;
}
这是当年我做6.0的时候专为处理jpg写的
当然还可以扩展成其他格式的
这个方法很快我就淘汰了
后来我又写了个GDI+的
不过对于你来说应该正合适
if(SUCCEEDED(OleLoadPicture(pStm,fstatus.m_size,TRUE,IID_IPicture,(LPVOID*)pPic)))
{ OLE_XSIZE_HIMETRIC hmWidth;
OLE_YSIZE_HIMETRIC hmHeight;
pPic->get_Width(&hmWidth);
pPic->get_Height(&hmHeight);
}
能否直接把你的.CPP和.H发到
void CBmpToJpgDlg::OnButton7()
{
// TODO: Add your control notification handler code here UpdateData();
IPicture *pPic;
IStream *pStm;
BOOL bResult;
HANDLE hFile=NULL;
DWORD dwFileSize,dwByteRead;
long nScrWidth;
long nScrHeight;
char *lpstrFile="E:\\Documents and Settings\\test1\\桌面\\EMFtoPDF\\BmpToJpg\\input01.jpg";
hFile=CreateFile(lpstrFile,GENERIC_READ,
FILE_SHARE_READ,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL);
dwFileSize=GetFileSize(hFile,NULL);//获取文件字节数
HGLOBAL hGlobal = GlobalAlloc(GMEM_MOVEABLE, dwFileSize);
LPVOID pvData = NULL; ReadFile(hFile,pvData,dwFileSize,&dwByteRead,NULL);//把文件读入内存缓冲区
GlobalUnlock(hGlobal);
CreateStreamOnHGlobal(hGlobal, TRUE, &pStm);
//装入图形文件
bResult=OleLoadPicture(pStm,dwFileSize,TRUE,IID_IPicture,(LPVOID*)&pPic);
OLE_XSIZE_HIMETRIC hmWidth;//图片的真实宽度
OLE_YSIZE_HIMETRIC hmHeight;//图片的真实高度
nScrWidth=pPic->get_Width(&hmWidth); //这里报错,调试结果是pPic空
nScrHeight=pPic->get_Height(&hmHeight);
pPic->Release();
CloseHandle(hFile);//关闭打开的文件
UpdateData(false);
}
上面的问题需要怎么解决啊,兄弟们
void CBmpToJpgDlg::OnButton7()
{
// TODO: Add your control notification handler code here UpdateData();
IPicture *pPic;
IStream *pStm;
BOOL bResult;
HANDLE hFile=NULL;
DWORD dwFileSize,dwByteRead;
long nScrWidth;
long nScrHeight;
char *lpstrFile="E:\\Documents and Settings\\test1\\桌面\\EMFtoPDF\\BmpToJpg\\input01.jpg";
hFile=CreateFile(lpstrFile,GENERIC_READ,
FILE_SHARE_READ,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL);
dwFileSize=GetFileSize(hFile,NULL);
HGLOBAL hGlobal = GlobalAlloc(GMEM_MOVEABLE, dwFileSize);
LPVOID pvData = NULL; ReadFile(hFile,pvData,dwFileSize,&dwByteRead,NULL);
GlobalUnlock(hGlobal);
CreateStreamOnHGlobal(hGlobal, TRUE, &pStm);
bResult=OleLoadPicture(pStm,dwFileSize,TRUE,IID_IPicture,(LPVOID*)&pPic);
OLE_XSIZE_HIMETRIC hmWidth;
OLE_YSIZE_HIMETRIC hmHeight;
nScrWidth=pPic->get_Width(&hmWidth); 这里报错,调试出来的结果是pPic为空,但是我再网上看到的都是这样写的啊,都没有给这个指针赋值啊
nScrHeight=pPic->get_Height(&hmHeight);
pPic->Release();
CloseHandle(hFile);
UpdateData(false);
}
上面的问题怎么解决啊?兄弟们
刚才发的报错注释的不明显,所以重发一次~~
谢谢啦,呵呵
基于ATL的类跟其他类的使用方式是不是都一样啊?只要把.CPP和.H都INSERT进来就好了,是吗?
{
CArchiveStream arcstream(&ar);MFC中只有CArchive类
return Load((IStream*)&arcstream);
}如果我改成CArchive,有报这样的错误:
error C2664: '__thiscall CArchive::CArchive(const class CArchive &)' : cannot convert parameter 1 from 'class CArchive *' to 'const class CArchive &'
Reason: cannot convert from 'class CArchive *' to 'const class CArchive'
No constructor could take the source type, or constructor overload resolution was ambiguous
该怎么解决呢?我是菜鸟啦~~