C#: 缩放图片

直接上代码：

    /// <summary>
    /// 根据指定宽度等比例缩放图片
    /// </summary>
    /// <param name="image"></param>
    /// <param name="width"></param>
    /// <param name="height"></param>
    /// <returns></returns>
    public static Bitmap ResizeImage(Image image, int width)
    {
        int sourceWidth = image.Width;
        int sourceHeight = image.Height;

        float nPercent = 0;
        float nPercentW = 0;
        float nPercentH = 0;

        nPercentW = ((float)width / (float)sourceWidth);
        nPercentH = ((float)width / (float)sourceHeight);

        if (nPercentH < nPercentW)
            nPercent = nPercentH;
        else
            nPercent = nPercentW;

        int destWidth = (int)(sourceWidth * nPercent);
        int destHeight = (int)(sourceHeight * nPercent);

        OrientationImage(image);

        return ResizeImage(image, destWidth, destHeight);
    }

    /// <summary>
    /// 根据指定宽度、高度缩放图片
    /// </summary>
    /// <param name="image"></param>
    /// <param name="width"></param>
    /// <param name="height"></param>
    /// <returns></returns>
    public static Bitmap ResizeImage(Image image, int width, int height)
    {
        var destRect = new Rectangle(0, 0, width, height);
        var destImage = new Bitmap(width, height);

        destImage.SetResolution(image.HorizontalResolution, image.VerticalResolution);

        using (var graphics = Graphics.FromImage(destImage))
        {
            graphics.CompositingMode = CompositingMode.SourceCopy;
            graphics.CompositingQuality = CompositingQuality.HighQuality;
            graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
            graphics.SmoothingMode = SmoothingMode.HighQuality;
            graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;

            using (var wrapMode = new ImageAttributes())
            {
                wrapMode.SetWrapMode(WrapMode.TileFlipXY);
                graphics.DrawImage(image, destRect, 0, 0, image.Width, image.Height, GraphicsUnit.Pixel, wrapMode);
            }
        }

        return destImage;
    }