VC/MFC加载图片（JPG、JPEG、BMP）

最新推荐文章于 2022-12-04 21:55:09 发布

zhongyu627

最新推荐文章于 2022-12-04 21:55:09 发布

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分类专栏： MFC 文章标签： imagelist null float buffer path image

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本文介绍了一种在Windows应用程序中使用C++加载并显示jpg和bmp格式图片的方法。通过创建图像列表并将其附加到列表控件上，实现了图片的缩放及显示。此外，还详细介绍了关键函数LoadPicture的具体实现。

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//加载jpg图片
int m_TotCount;
CImageList m_ImageList;

CListCtrl m_List;
HIMAGELIST hScreens = ImageList_Create(THUMWIDTH, THUMHEIGHT, ILC_COLOR32, 0, 1);
m_ImageList.Attach(hScreens);

m_list.SetImageList(&m_ImageList, LVSIL_NORMAL);

for (int i = 0; i<4; i++ )
{
CString ss;
ss.Format("%d",i);
HBITMAP bitm=LoadPicture( GetExeAbsolutePath()+ss+".jpg" );
if (bitm!=NULL)
{
m_TotCount=m_list.GetItemCount();
CBitmap* pImage = NULL;
pImage = new CBitmap();
pImage->Attach(bitm);
int imgP=m_ImageList.Add(pImage,RGB(0,0,0));
m_list.InsertItem(m_TotCount,ss+".jpg",imgP);
m_list.SetItemText(m_TotCount, 1, ss+".jpg");
}
}

//加载Jpg、Bmp图片，这个函数是关键代码！！！！！！！
HBITMAP CAddbmpDlg::LoadPicture(CString mFile)
{
CString pFSize;
WCHAR wpath[MAX_PATH];
MultiByteToWideChar(CP_ACP, 0, mFile, -1, wpath, MAX_PATH);

IPicture* pPic;
OleLoadPicturePath(wpath, NULL, NULL, NULL, IID_IPicture,(LPVOID*)&pPic);

if (pPic==NULL) return NULL;
HBITMAP hPic = NULL;
pPic->get_Handle((UINT*)&hPic);

long nWidth=THUMWIDTH;
long nHeight=THUMHEIGHT;

long mWid,mHei;
pPic->get_Height(&mHei);
pPic->get_Width(&mWid);

HBITMAP hPicRet = (HBITMAP)CopyImage(hPic, IMAGE_BITMAP, nWidth, nHeight , LR_COPYDELETEORG);

HBRUSH hBrushBorder=::CreateSolidBrush(RGB(192, 192, 192));
HBRUSH hBrushBk=::CreateSolidBrush(RGB(255, 255, 255));

RECT rcBorder;
rcBorder.left=rcBorder.top=0;
rcBorder.right=THUMWIDTH;
rcBorder.bottom=THUMHEIGHT;

const float fRatio=(float)THUMHEIGHT/THUMWIDTH;

int XDest, YDest, nDestWidth, nDestHeight;

const float fImgRatio=(float)mHei/mWid;
if(fImgRatio > fRatio)
{
nDestWidth=(THUMHEIGHT/fImgRatio);
XDest=(THUMWIDTH-nDestWidth)/2;
YDest=0;
nDestHeight=THUMHEIGHT;
}
else
{
XDest=0;
nDestWidth=THUMWIDTH;
nDestHeight=(THUMWIDTH*fImgRatio);
YDest=(THUMHEIGHT-nDestHeight)/2;
}

CClientDC cdc(this);
HDC hDC=::CreateCompatibleDC(cdc.m_hDC);
HBITMAP bm = CreateCompatibleBitmap(cdc.m_hDC, THUMWIDTH, THUMHEIGHT);
HBITMAP pOldBitmapImage = (HBITMAP)SelectObject(hDC,bm);
::FillRect(hDC, &rcBorder, hBrushBk);
::FrameRect(hDC, &rcBorder, hBrushBorder);
HBITMAP hBmReturn= (HBITMAP)::SelectObject(hDC, pOldBitmapImage);

CDC hdcSrc, hdcDst;

hdcSrc.CreateCompatibleDC(NULL);
hdcDst.CreateCompatibleDC(NULL);

// Load the bitmaps into memory DC
CBitmap* hbmSrcT = (CBitmap*) hdcSrc.SelectObject(hPicRet);
CBitmap* hbmDstT = (CBitmap*) hdcDst.SelectObject(hBmReturn);

hdcDst.BitBlt(XDest,YDest,nDestWidth, nDestHeight, &hdcSrc,0,0,SRCCOPY);
pOldBitmapImage = (HBITMAP)SelectObject(hdcDst.m_hDC,bm);

DeleteDC(hDC);
DeleteObject(hBrushBorder);
DeleteObject(hBrushBk);

return pOldBitmapImage;
}

CString CAddbmpDlg::GetExeAbsolutePath()
{
char buffer[ MAX_PATH ];
CString ExePath = "";
GetModuleFileName( NULL, buffer, MAX_PATH );
ExePath=CString( buffer );
ExePath=ExePath.Left(
ExePath.ReverseFind( '\\' )>ExePath.ReverseFind( '/' )?
ExePath.ReverseFind( '\\' )+ 1:
ExePath.ReverseFind( '/' )+1
);
return ExePath;
}

转载： http://blog.sina.com.cn/s/blog_4b44e1c0010095sf.html