WTL中图片控件上PNG图不透明

Question

用WTL框架 在图片控件上贴图后不透明
这段是加载图片：bool ShowJpgGif(CImage& img,char* strPath)
{
IStream pStm;

int len = 0;

FILE f = fopen(strPath,"rb");

if (f != NULL)

{

fseek(f,0,SEEK_END);

len = ftell(f);

rewind(f);

HGLOBAL hGlobal = GlobalAlloc(GMEM_MOVEABLE, len);

LPVOID pvData = NULL;

if (hGlobal != NULL)

{

pvData = GlobalLock(hGlobal);

if (pvData != NULL)

{

fread(pvData,1,len,f);

fclose(f);

GlobalUnlock(hGlobal);

CreateStreamOnHGlobal(hGlobal, TRUE, &pStm);

img.Load(pStm);
if (img.GetBPP() == 32)
{
int i;
int j;
for (i = 0; i < img.GetWidth(); i++)
{
for (j = 0; j < img.GetHeight(); j++)
{
byte *pByte = (byte *)img.GetPixelAddress(i, j);
pByte[0] = pByte[0] * pByte[3] / 255;
pByte[1] = pByte[1] * pByte[3] / 255;
pByte[2] = pByte[2] * pByte[3] / 255;
}
}
}
GlobalFree(pStm);
return true;
}
else
return false;
}

else
return false;
}

这段是贴图上去
if(!ShowJpgGif(m_myImg,".\\res\\mainfram\\app.png"))
    return ;
m_hBitmap = m_myImg.Detach(); 
m_quit = GetDlgItem(IDC_STATIC_APP);
m_quit.SetBitmap(m_hBitmap); 


求各位大侠相助啊