MFC - GetPixel Doesnt Work - HELP!

[ITHODVGK]

In an SDI application I created a new Class, say, CTest.

In one of the member functions of CTest I included the following code -

void CTest::SomeFunc(...)
{ 
     ...
  
     int x;
  
     int y;
     ...

     CFrameWnd* pFrame = (CFrameWnd*)(AfxGetApp()->m_pMainWnd);
     CMyAppView* pView = (CMyAppView*)(pFrame->GetActiveView());
     CClientDC dc(pView);

     COLORREF pix = dc.GetPixel(x, y);
  
     ...
}

But the function GetPixel doent return the correct value of the the pixel color at (x,y);

when I debugged it pix always had the value 0xffffffff.

Please help...

 

[palbano]

You have the wrong idea of how a device context works. When you create one it is empty and is meant to be used to draw to the device or to transfer data to the device memory i.e., video memory.

So you can't just create one that has all the data in it that has already been transfered to the video memory.

-pete
_{I just can't seem to get back my IntelliSense}

 

[ITHODVGK]

So How do I implement a GetPixel Function from an external class?