使用MaxHeight和MaxWidth约束按比例调整图像大小

像这样？

public static void Test(){    using (var image = Image.FromFile(@"c:logo.png"))    using (var newImage = ScaleImage(image, 300, 400))    {        newImage.Save(@"c:test.png", ImageFormat.Png);    }}public static Image ScaleImage(Image image, int maxWidth, int maxHeight){    var ratioX = (double)maxWidth / image.Width;    var ratioY = (double)maxHeight / image.Height;    var ratio = Math.Min(ratioX, ratioY);    var newWidth = (int)(image.Width * ratio);    var newHeight = (int)(image.Height * ratio);    var newImage = new Bitmap(newWidth, newHeight);    using (var graphics = Graphics.FromImage(newImage))        graphics.DrawImage(image, 0, 0, newWidth, newHeight);    return newImage;}