aspect ratio of image crashing the program

问题

here is the code this code is to maintain the aspect ratio of the image it crashes when the control goes to int WindowRatio = WidthOfPreviewPane / HeightOfPreviewPane; can anyone give idea why ??

int WidthOfPreviewPane = RECTWIDTH(m_rcParent); 
int HeightOfPreviewPane = RECTHEIGHT(m_rcParent) ; 

int ImageRatio = WidthOfImage / HeightOfImage;
int WindowRatio = WidthOfPreviewPane / HeightOfPreviewPane;

if (WindowRatio > ImageRatio && WidthOfPreviewPane< WidthOfImage)
{
    m_iFinalHeight = HeightOfPreviewPane;
    m_iFinalWidth = m_iFinalHeight * ImageRatio;
    MessageBox(NULL, L"1",L"Error", 
            MB_ICONERROR | MB_OK);
}
else if (WindowRatio < ImageRatio && WidthOfPreviewPane< WidthOfImage)
{
    m_iFinalWidth = WidthOfPreviewPane;
    m_iFinalHeight = m_iFinalWidth / ImageRatio;
        MessageBox(NULL, L"2",L"Error", 
            MB_ICONERROR | MB_OK);
}
else if(WindowRatio > ImageRatio && WidthOfPreviewPane> WidthOfImage)
{
    m_iFinalHeight = HeightOfImage;
    m_iFinalWidth = WidthOfImage;
        MessageBox(NULL, L"3",L"Error", 
            MB_ICONERROR | MB_OK);

}
else if(WindowRatio < ImageRatio && WidthOfPreviewPane> WidthOfImage)
{
    m_iFinalHeight = HeightOfImage;
    m_iFinalWidth = WidthOfImage;
        MessageBox(NULL, L"4",L"Error", 
            MB_ICONERROR | MB_OK);

}

回答1:

the logic of this algo is correct finally i found that WidthOfPreviewPane and HeightOfPreviewPane=0 its because the function in which i have written this code was initialized at last so these 2 were not initialized that time when i debugged them and i avoided thid problem by putting them in in a if condition which will let the control go inside if their value is not 0 and it worked nicely. see this-

 if(WidthOfPreviewPane!= 0 && HeightOfPreviewPane!=0 )
            {
                  conditions here......

            }

and thats solved.

来源：https://stackoverflow.com/questions/17746156/aspect-ratio-of-image-crashing-the-program