有一个内存泄露的问题，窗口切换多次后泄露，窗口里面含自绘图片按钮

Question

问题如题：

Answer 1

网友们帮我看看啊，我实在找不出来了
代码如下：void MyButton::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct) 
{ CString sCaption;
HDC h_clientDC;
CRect rect;
CDC *pDC; h_clientDC = lpDrawItemStruct->hDC;
pDC = CDC::FromHandle(lpDrawItemStruct->hDC);
GetWindowText(sCaption);
rect = lpDrawItemStruct->rcItem;

pDC->SetBkMode(TRANSPARENT); PaintButton(lpDrawItemStruct->hDC);

}
HBITMAP MyButton::LoadImagFile(CString strFileName)
{
IImagingFactory *pImgFactory =NULL;  
    IImage *pImage =NULL;  
    CoInitializeEx(NULL,COINIT_MULTITHREADED); 
HBITMAP hResult =0;  
    if   (SUCCEEDED(CoCreateInstance(CLSID_ImagingFactory,  
                                     NULL,  
                                     CLSCTX_INPROC_SERVER,  
                                     IID_IImagingFactory,  
                                     (void   **)&pImgFactory)))  
{  
     ImageInfo imageInfo;  
        if(SUCCEEDED(pImgFactory->CreateImageFromFile(strFileName,&pImage))  
&& SUCCEEDED(pImage->GetImageInfo(&imageInfo)))  
        {  
CWindowDC dc(0);  
CDC dcBitmap;  
dcBitmap.CreateCompatibleDC(&dc);  
hResult =CreateCompatibleBitmap(dc.GetSafeHdc(),imageInfo.Width,imageInfo.Height);  
if(hResult){  
HGDIOBJ   hOldBitmap   =   dcBitmap.SelectObject(hResult);  
                pImage->Draw(dcBitmap.GetSafeHdc(),CRect(0,0,imageInfo.Width,imageInfo.Height),NULL);  
dcBitmap.SelectObject(hOldBitmap);     
}  
pImage->Release();  
        } 
        pImgFactory->Release();  
}
  //释放资源
    if(pImage != NULL)
     {
         pImage->Release();
         pImage = NULL;
     }    if(pImgFactory != NULL)
     {
         pImgFactory->Release();
         pImgFactory = NULL;
     }
CoUninitialize(); 
return hResult;
}
void MyButton::PaintButton(HDC h_destDC)
{
CRect cltRect;
BITMAP bmp;
HDC hDC; HBITMAP  jpgbmp; if(BUTTON_STATE==BUTTON_DOWN)
{
jpgbmp = LoadImagFile(m_strdown);
}
else if(BUTTON_STATE==BUTTON_UP)
{
jpgbmp = LoadImagFile(m_strup);
} ::GetObject(jpgbmp, sizeof(bmp), &bmp);
hDC = ::CreateCompatibleDC(NULL);
SelectObject(hDC, jpgbmp);
::TransparentImage(h_destDC, 0, 0, cltRect.Width(), cltRect.Height(), 
hDC, 0, 0, cltRect.Width(), cltRect.Height(), RGB(255,255,255));
::DeleteObject(jpgbmp);
::DeleteDC(hDC);}void MyButton::OnLButtonUp(UINT nFlags, CPoint point) 
{
BUTTON_STATE=BUTTON_UP;
CButton::OnLButtonUp(nFlags, point);
}
void MyButton::OnLButtonDown(UINT nFlags, CPoint point) 
{ BUTTON_STATE=BUTTON_DOWN; CButton::OnLButtonDown(nFlags, point);
}

Answer 2

窗口切换多次后引发错误，很有可能是在切换一个窗口后，在另一个窗口状态下你还在调用先前窗口的指针；
或者是你先NEW了一个窗口指针，但是当再次切换到该窗口时，又再次NEW了次，这样就会出问题了。
所以建议你检查下窗口指针的处理情况

Answer 3

其实不长，重点的代码就只有这个，帮我看看
void MyButton::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct)  
{
CString sCaption;
HDC h_clientDC;
CRect rect;
CDC *pDC;
h_clientDC = lpDrawItemStruct->hDC;
pDC = CDC::FromHandle(lpDrawItemStruct->hDC);
GetWindowText(sCaption);
rect = lpDrawItemStruct->rcItem;
pDC->SetBkMode(TRANSPARENT);
PaintButton(lpDrawItemStruct->hDC);
}void MyButton::PaintButton(HDC h_destDC)
{
CRect cltRect;
BITMAP bmp;
HDC hDC;
HBITMAP jpgbmp;
if(BUTTON_STATE==BUTTON_DOWN)
{jpgbmp = LoadImagFile(m_strdown);}
else if(BUTTON_STATE==BUTTON_UP)
{jpgbmp = LoadImagFile(m_strup);}
::GetObject(jpgbmp, sizeof(bmp), &bmp);
hDC = ::CreateCompatibleDC(NULL);
SelectObject(hDC, jpgbmp);
::TransparentImage(h_destDC, 0, 0, cltRect.Width(), cltRect.Height(),  
hDC, 0, 0, cltRect.Width(), cltRect.Height(), RGB(255,255,255));
::DeleteObject(jpgbmp);
::DeleteDC(hDC);
}

Answer 4

CWindowDC dc(0);   
CDC dcBitmap;   
dcBitmap.CreateCompatibleDC(&dc);   这个需要释放 dcBitmap.Delete(); hResult =CreateCompatibleBitmap(dc.GetSafeHdc(),imageInfo.Width,imageInfo.Height);   
if(hResult){   
HGDIOBJ hOldBitmap = dcBitmap.SelectObject(hResult);   
  pImage->Draw(dcBitmap.GetSafeHdc(),CRect(0,0,imageInfo.Width,imageInfo.Height),NULL);   
dcBitmap.SelectObject(hOldBitmap); 

Answer 5

HBITMAP oldBmp = SelectObject(hDC, jpgbmp);
::TransparentImage(h_destDC, 0, 0, cltRect.Width(), cltRect.Height(),  
hDC, 0, 0, cltRect.Width(), cltRect.Height(), RGB(255,255,255));SelectObject(hDC, oldBmp);
::DeleteObject(jpgbmp);
::DeleteDC(hDC);

Answer 6

  
CDC dcBitmap;   
dcBitmap.CreateCompatibleDC(&dc); 
hResult =CreateCompatibleBitmap(dc.GetSafeHdc(),imageInfo.Width,imageInfo.Height);
// hResult 需要释放 DeleteObject(hResult) ;  
if(hResult){   
HGDIOBJ hOldBitmap = dcBitmap.SelectObject(hResult);   
  pImage->Draw(dcBitmap.GetSafeHdc(),CRect(0,0,imageInfo.Width,imageInfo.Height),NULL);   
dcBitmap.SelectObject(hOldBitmap);