图片处理

  #region 图片处理

        /// <summary>
        /// 生成缩略图重载方法1，返回缩略图的Image对象
        /// </summary>
        /// <param name="Width">缩略图的宽度</param>
        /// <param name="Height">缩略图的高度</param>
        /// <returns>缩略图的Image对象</returns>
        public Image GetReducedImage(int Width, int Height)
        {
            try
            {
                Image ResourceImage = Image.FromFile("");

                //用指定的大小和格式初始化Bitmap类的新实例
                Bitmap bitmap = new Bitmap(Width, Height, PixelFormat.Format32bppArgb);
                //从指定的Image对象创建新Graphics对象
                Graphics graphics = Graphics.FromImage(bitmap);
                //清除整个绘图面并以透明背景色填充
                graphics.Clear(Color.Transparent);
                //在指定位置并且按指定大小绘制原图片对象
                graphics.DrawImage(ResourceImage, new Rectangle(0, 0, Width, Height));
                return bitmap;
            }
            catch (Exception e)
            {
                
                return null;
            }
        }


        /// <summary>
        /// 截取图片方法
        /// </summary>
        /// <param name="url">图片地址</param>
        /// <param name="beginX">开始位置-X</param>
        /// <param name="beginY">开始位置-Y</param>
        /// <param name="getX">截取宽度</param>
        /// <param name="getY">截取长度</param>
        /// <param name="fileName">文件名称</param>
        /// <param name="savePath">保存路径</param>
        /// <param name="fileExt">后缀名</param>
        public static string CutImage(string url, int beginX, int beginY, int getX, int getY, string fileName, string savePath, string fileExt)
        {
            if ((beginX < getX) && (beginY < getY))
            {
                Bitmap bitmap = new Bitmap(url);//原图
                if (((beginX + getX) <= bitmap.Width) && ((beginY + getY) <= bitmap.Height))
                {
                    Bitmap destBitmap = new Bitmap(getX, getY);//目标图
                    Rectangle destRect = new Rectangle(0, 0, getX, getY);//矩形容器
                    Rectangle srcRect = new Rectangle(beginX, beginY, getX, getY);

                    Graphics.FromImage(destBitmap);
                    //Graphics.DrawImage(bitmap, destRect, srcRect, GraphicsUnit.Pixel);

                
                    ImageFormat format = ImageFormat.Png;
                    switch (fileExt.ToLower())
                    {
                        case "png":
                            format = ImageFormat.Png;
                            break;
                        case "bmp":
                            format = ImageFormat.Bmp;
                            break;
                        case "gif":
                            format = ImageFormat.Gif;
                            break;
                    }
                    destBitmap.Save(savePath + "//" + fileName, format);
                    return savePath + "\" + "*" + fileName.Split('.')[0] + "." + fileExt;
                }
                else
                {
                    return "截取范围超出图片范围";
                }
            }
            else
            {
                return "请确认(beginX < getX)&&(beginY < getY)";
            }
        }

        #endregion