//功能:根据时间创建目录
        //输入参数:"uploadfiles/images/"
        //输出参数:"uploadfiles/images/2018/03/21/"
        private static string CreateDateDir(string strDefaultDirName)
        {
            string strRootPath = HttpContext.Current.Request.PhysicalApplicationPath;
            string strPath     = strDefaultDirName;

            strPath += DateTime.Now.ToString("yyyy") + "/";
            strPath += DateTime.Now.ToString("MM") + "/";
            strPath += DateTime.Now.ToString("dd") + "/";
            HelperFile.CreateDirectory(strRootPath + strPath);
            return(strPath);
        }
        //绘制文本水印
        private static void DrawTxtWaterMark(ModelUploadFileConfig objConfig)
        {
            if (!File.Exists(objConfig.ServerFileFullPath))
            {
                objConfig.OPFlag    = false;
                objConfig.OPMessage = "文件不存在,加水印失败。";
                return;
            }
            Image objImg = Image.FromFile(objConfig.ServerFileFullPath);

            switch (objImg.PixelFormat)
            {
            case PixelFormat.Format1bppIndexed:
            case PixelFormat.Format4bppIndexed:
            case PixelFormat.Format8bppIndexed:
            case PixelFormat.Undefined:
            case PixelFormat.Format16bppArgb1555:
            case PixelFormat.Format16bppGrayScale:
                objConfig.OPFlag    = false;
                objConfig.OPMessage = "上传的图片包含不正确的像素格式,不能加水印!";
                objImg.Dispose();
                return;

            default:
                break;
            }
            Graphics g = null;
            Font     f = new Font("Verdana", 12f, FontStyle.Bold);
            Brush    b = new SolidBrush(Color.Red);

            try
            {
                g = Graphics.FromImage(objImg);
                g.DrawImage(objImg, 0, 0, objImg.Width, objImg.Height);
                g.DrawString(objConfig.WaterMarkTxtString, f, b, Convert.ToSingle(objConfig.WaterMarkMarginRight), Convert.ToSingle(objConfig.WaterMarkMarginBottom));
                objConfig.ServerFileHasWMFullPath = RenameFile(objConfig.ServerFileFullPath);
                objImg.Save(objConfig.ServerFileHasWMFullPath);
                objConfig.OPFlag = true;
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                f.Dispose();
                b.Dispose();
                g.Dispose();
                objImg.Dispose();
                HelperFile.DeleteFile(objConfig.ServerFileHasWMFullPath);
            }
        }
        //绘制图片水印
        private static void DrawPicWaterMark(ModelUploadFileConfig objConfig)
        {
            if (!File.Exists(objConfig.ServerFileFullPath))
            {
                objConfig.OPFlag    = false;
                objConfig.OPMessage = "图片文件不存在,加水印失败。";
                return;
            }
            string strRootPath = System.Web.HttpContext.Current.Request.PhysicalApplicationPath;

            objConfig.WaterMarkImagePath = strRootPath + objConfig.WaterMarkImagePath;
            if (!File.Exists(objConfig.WaterMarkImagePath))
            {
                objConfig.OPFlag    = false;
                objConfig.OPMessage = "水印图片文件不存在,加水印失败。";
                return;
            }
            //将服务器端要加水印的图像文件载入到Image对象里
            Image objImg = Image.FromFile(objConfig.ServerFileFullPath);

            switch (objImg.PixelFormat)
            {
            case PixelFormat.Format1bppIndexed:
            case PixelFormat.Format4bppIndexed:
            case PixelFormat.Format8bppIndexed:
            case PixelFormat.Undefined:
            case PixelFormat.Format16bppArgb1555:
            case PixelFormat.Format16bppGrayScale:
                objConfig.OPFlag    = false;
                objConfig.OPMessage = "上传的图片包含不正确的像素格式,不能加水印。";
                objImg.Dispose();
                return;
            }
            //将水印图像文件载入到另一个Image对象里
            Image objWMImg = Image.FromFile(objConfig.WaterMarkImagePath);
            // 将保存了图像文件的Image对象存到一个Graphics对象里
            Graphics        g       = Graphics.FromImage(objImg);
            MemoryStream    objMS   = new MemoryStream();
            ImageAttributes imgAttr = new ImageAttributes();
            FileStream      objFS   = null;

            try
            {
                //获取要绘制图形坐标
                int x = objImg.Width - objConfig.WaterMarkMarginRight;
                int y = objImg.Height - objConfig.WaterMarkMarginBottom;
                //设置颜色矩阵
                float[][] matrixItems =
                {
                    new float[] {
                        1,
                        0,
                        0,
                        0,
                        0
                    },
                    new float[] {
                        0,
                        1,
                        0,
                        0,
                        0
                    },
                    new float[] {
                        0,
                        0,
                        1,
                        0,
                        0
                    },
                    new float[] {
                        0,
                        0,
                        0,
                        Convert.ToSingle(objConfig.WaterMarkTransparent) / 100f,
                        0
                    },
                    new float[] {
                        0,
                        0,
                        0,
                        0,
                        1
                    }
                };
                ColorMatrix colorMatrix = new ColorMatrix(matrixItems);
                imgAttr.SetColorMatrix(colorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
                g.SmoothingMode = SmoothingMode.AntiAlias;
                //在Graphics对象里绘制水印图像,此时,和这个Graphics对象相关联的服务器文件也跟着被画上了水印
                g.DrawImage(objWMImg, new Rectangle(x, y, objWMImg.Width, objWMImg.Height), 0, 0, objWMImg.Width, objWMImg.Height, GraphicsUnit.Pixel, imgAttr);
                //读取原来服务器端要写入水印的文件的文件类型
                FileInfo    objFile   = new FileInfo(objConfig.ServerFileFullPath);
                ImageFormat imageType = default(ImageFormat);
                switch (objFile.Extension.ToLower())
                {
                case ".jpg":
                    imageType = ImageFormat.Jpeg;
                    break;

                case ".jpeg":
                    imageType = ImageFormat.Jpeg;
                    break;

                case ".gif":
                    imageType = ImageFormat.Gif;
                    break;

                case ".png":
                    imageType = ImageFormat.Png;
                    break;

                case ".bmp":
                    imageType = ImageFormat.Bmp;
                    break;

                case ".tif":
                    imageType = ImageFormat.Tiff;
                    break;

                case ".wmf":
                    imageType = ImageFormat.Wmf;
                    break;

                case ".ico":
                    imageType = ImageFormat.Icon;
                    break;

                default:
                    imageType = ImageFormat.Jpeg;
                    break;
                }
                // 将已经画好水印的Image对象保存到内存流中
                objImg.Save(objMS, imageType);
                // 将内存流以数组形式保存到图像数组里
                byte[] imgData = objMS.ToArray();
                //将写了水印的图像数组存入改了名的文件
                objFS = new FileStream(RenameFile(objConfig.ServerFileFullPath), FileMode.Create, FileAccess.Write);
                if ((objFS != null))
                {
                    objFS.Write(imgData, 0, imgData.Length);
                }
                objConfig.OPFlag = true;
                objConfig.ServerFileHasWMFullPath = RenameFile(objConfig.ServerFileFullPath);
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                objFS.Close();
                objFS.Dispose();
                objFS = null;
                objImg.Dispose();
                objImg = null;
                objWMImg.Dispose();
                objWMImg = null;
                g.Dispose();
                g = null;
                objMS.Close();
                objMS.Dispose();
                objMS = null;
                imgAttr.Dispose();
                imgAttr = null;
                HelperFile.DeleteFile(objConfig.ServerFileHasWMFullPath);
            }
        }