c# 图片格式转换

        public void ImageFormatter(string sourcePath, string distationPath, string format) {
            System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(sourcePath);
            switch (format.ToLower()) {
                case "bmp":
                    bitmap.Save(distationPath, System.Drawing.Imaging.ImageFormat.Bmp);
                    break;
                case "emf":
                    bitmap.Save(distationPath, System.Drawing.Imaging.ImageFormat.Emf);
                    break;
                case "gif":
                    bitmap.Save(distationPath, System.Drawing.Imaging.ImageFormat.Gif);
                    break;
                case "ico":
                    bitmap.Save(distationPath, System.Drawing.Imaging.ImageFormat.Icon);
                    break;
                case "jpg":
                    bitmap.Save(distationPath, System.Drawing.Imaging.ImageFormat.Jpeg);
                    break;
                case "png":
                    bitmap.Save(distationPath, System.Drawing.Imaging.ImageFormat.Png);
                    break;
                case "tif":
                    bitmap.Save(distationPath, System.Drawing.Imaging.ImageFormat.Tiff);
                    break;
                case "wmf":
                    bitmap.Save(distationPath, System.Drawing.Imaging.ImageFormat.Wmf);
                    break;
                default: throw new Exception("无法转换此格式！");
            }
        }