Question

I noticed using task manager that the following code has a GDI leak in it. The count of GDI object in the process executing this code increases by 1 each time it executes however I can’t seem to find the problem.

Any help would be appreciated.

// create new DC based on current     HDC hDC = CreateCompatibleDC(GetDC()); // select a bitmap into the new DC and keep the old one HGDIOBJ hOldObj = SelectObject (hDC,hBM); // do somthing here --> 100% no leak here SomeFunction (hDC); // select the old object back from whence it came and delete whats returned    DeleteObject (SelectObject (hDC,hOldObj)); // delete the DC DeleteDC(hDC); // delete the tmp object DeleteObject (hOldObj); 

RM

Answer 1

Copying from the comment, I didn’t put it as answer as I can’t test it and I was not sure if it was correct, please test it.

In general it is not a good idea to have nested calls ie

HDC hDC1 = GetDC();  HDC hDC2 = CreateCompatibleDC(hDC1);  ..  

instead of

HDC hDC = CreateCompatibleDC(GetDC());  

(BTW in your code the HDC returned by GetDC is not released.)