C#实现二维码生成与水印添加技术详解

        /// <param name="rSrcImgPath">原始图片的物理路径</param>      
        /// <param name="rMarkImgPath">水印图片的物理路径</param>      
        /// <param name="rDstImgPath">输出合成后的图片的物理路径</param>      
        public void BuildWatermark(string rSrcImgPath, string rMarkImgPath, string rDstImgPath, int location)
        {
            //进行水印添加处理--------------------------------------------
            //加载文件
            System.Drawing.Image Cover = System.Drawing.Image.FromFile(rSrcImgPath);
            //加载水印文件
            //string shuiyin =   "images/watermark.png";
            //System.Drawing.Image water = System.Drawing.Image.FromFile(Request.MapPath(rMarkImgPath));
            System.Drawing.Image water = System.Drawing.Image.FromFile(rMarkImgPath);

            //创建画布
            Graphics g = Graphics.FromImage(Cover);
            if (location == 1)//左上方
            {
                //在image上绘制水印
                g.DrawImage(water, new Rectangle(0, 0, water.Width, water.Height), 0, 0, water.Width, water.Height, GraphicsUnit.Pixel);
            }
            else if (location == 2)//左下方
            {
                //在image上绘制水印
                g.DrawImage(water, new Rectangle(0, Cover.Height - water.Height, water.Width, water.Height), 0, 0, water.Width, water.Height, GraphicsUnit.Pixel);
            }
            else if (location == 3)//右上方
            {
                //在image上绘制水印
                g.DrawImage(water, new Rectangle(Cover.Width - water.Width, 0, water.Width, water.Height), 0, 0, water.Width, water.Height, GraphicsUnit.Pixel);
            }