C#任意变换图像大小

	
 
  
	/// 任意变换图片
        /// 
        /// 需要变换的图片
        /// 新宽度
        /// 新高度
        /// 
        private static Bitmap GetNewBitmap(Bitmap oldBitmap, int newWidth, int newHeight)
        {
            Bitmap newBitmap = new Bitmap(newWidth, newHeight);
            if (oldBitmap.Width == newWidth && oldBitmap.Height == newHeight) {
                newBitmap = oldBitmap;
            }
            else {
                Graphics g = Graphics.FromImage(newBitmap);
                g.InterpolationMode = InterpolationMode.HighQualityBicubic;
                g.SmoothingMode = SmoothingMode.HighQuality;
                g.CompositingQuality = CompositingQuality.HighQuality;
                g.DrawImage(oldBitmap, new Rectangle(0, 0, newWidth, newHeight), 
		    new Rectangle(0, 0, oldBitmap.Width, oldBitmap.Height), 
                    GraphicsUnit.Pixel);
                g.Dispose();
            }
            return newBitmap;
        }