C＃图片调整大小数学问题

Question

So I have a simple bit of code that re-sizes my profile images as they are consumed, problem is, the C# code isn't working the way I expected...

Here's the bit of code inside of the Controller Action Method for the Index View, where I'm doing this...

    string fullFileName = HttpContext.Server.MapPath(profile.ProfilePhotoPath);
    System.Drawing.Image img = System.Drawing.Image.FromFile(fullFileName);
    int width = img.Width;
    int height = img.Height;

    float reductionPercentage = 0F;

    if (width >= height)
    {
        reductionPercentage = (282 / width);
    }
    if (width < height)
    {
        reductionPercentage = (337 / height);
    }

    int newWidth = (int)Math.Round(width * reductionPercentage);
    int newHeight = (int)Math.Round(height * reductionPercentage);

    ViewBag.newWidth = newWidth;
    ViewBag.newHeight = newHeight;

Every part of this works perfectly, except when it hits the "reductionPercentage = * "

If the image is smaller or the same size, the reductionPercentage does exactly as it should and assign the value 1 to the reductionPercentage, however, if the image is larger, it's like it doesn't do the math at all, it always spits out 0 as the value for the reductionPercentage...

Any ideas, what could I possibly doing wrong?

Answer 1

(282 / width) and (337 / height) are integer division - when the denominator is larger than the numerator, you will get 0 as a result.

Make one of the division participants a float to ensure floating point division.

if (width >= height)
{
    reductionPercentage = (282f / width);
}
if (width < height)
{
    reductionPercentage = (337f / height);
}

Answer 2

Because 282 , 337 , width , and height are all integers, the / operator performs an integer division, truncating any fractional part of the result. Use 282f and 337f instead:

if (width >= height)
{
    reductionPercentage = 282f / width;
}
else
{
    reductionPercentage = 337f / height;
}

The f suffix signals that the number is a float instead of an int , so that a floating-point division is performed.