i do this in MFC, why it always TRACE out -1 ?? and alsoo , there is nothing printed when use BitBlt to print it out.Code:CDC twdc; twdc.CreateCompatibleDC(this->GetDC()); //=== gen pattern ===// for( int x=0 ; x<99 ; x++ ){ for( int y=0 ; y<99 ; y++ ){ twdc.SetPixelV( x,y, x*x+y*y ); } } TRACE( "%d", twdc.GetPixel(4,4) ); // any number for the (4,4).
i think i have problem with the CreateCompatibleDC().
help me please.