c# - 如何在 C# 中调整图像的大小以保持纵横比

Question

我需要知道一种方法来调整图像大小以适应盒子，而图像不会过度拉伸(stretch)。该框已设置宽度和高度，我希望图像尽可能多地填充框，但要保持它原来的纵横比。

Answer 1

//calculate the ratio
double dbl = (double)image.Width / (double)image.Height;

//set height of image to boxHeight and check if resulting width is less than boxWidth, 
//else set width of image to boxWidth and calculate new height
if( (int)((double)boxHeight * dbl) <= boxWidth )
{
    resizedImage = new Bitmap(original, (int)((double)boxHeight * dbl), boxHeight);
}
else
{
    resizedImage = new Bitmap(original, boxWidth, (int)((double)boxWidth / dbl) );
}

同比例缩放的公式为:

newWidth =  (int)((double)boxHeight * dbl)

or

newHeight =  (int)((double)boxWidth / dbl)