Asp.net 文件上传基类(取得文件后缀名,保存文件,加入文字水印)

/############################################
版权声明：
文章内容为本站编辑,创作.你可以任意转载、发布、使用但请务必标明文章原始出处及本声明
http://www.opent.cn  作者:浪淘沙
############################################/

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;
using System.IO;
using System.Drawing.Imaging;

namespace EC
{
    /// <summary>
    /// 上传类
    /// </summary>
    public class UploadObj
    {

        public UploadObj()
        {
            //
            // TODO: 在此处添加构造函数逻辑
            //
        }
        /// <summary>
        /// 允许文件上传的类型枚举
        /// </summary>
        public enum FileType
        {
           jpg,gif,bmp,png           
        }

        #region 取得文件后缀
        /// <summary>
        /// 取得文件后缀
        /// </summary>
        /// <param name="filename">文件名称</param>
        /// <returns></returns>
        public static string GetFileExtends(string filename)
        {
            string ext = null;
            if (filename.IndexOf('.') > 0)
            {
                string[] fs = filename.Split('.');
                ext = fs[fs.Length - 1];
            }
            return ext;
        }
        #endregion

        #region 检测文件是否合法
        /// <summary>
        /// 检测上传文件是否合法
        /// </summary>
        /// <param name="fileExtends">文件后缀名</param>
        /// <returns></returns>
        public static bool CheckFileExtends(string fileExtends)
        {
            bool status = false;
            fileExtends = fileExtends.ToLower();
            string[] fe = Enum.GetNames(typeof(FileType));
            for (int i = 0; i < fe.Length; i++)
            {
                if (fe[i].ToLower() == fileExtends)
                {
                    status = true;
                    break;
                }
            }
            return status;
        }
        #endregion

        #region 保存文件
       /// <summary>
       /// 保存文件
       /// </summary>
       /// <param name="fpath">全路径,Server.MapPath()</param>
       /// <param name="myFileUpload">上传控件</param>
       /// <returns></returns>
        public static string PhotoSave(string fpath,FileUpload myFileUpload)
        {  
            string s = "";
            string fileExtends = "";
            string fileName = myFileUpload.FileName;
            if (fileName != "")
            {
                //取得文件后缀
                fileExtends = EC.UploadObj.GetFileExtends(fileName);
                if (!EC.UploadObj.CheckFileExtends(fileExtends))
                {
                    EC.MessageObject.ShowPre("上传文件类型不合法");                 
                }
                Random rd = new Random();
                s = EC.RandomObject.DateRndName(rd) + "." + fileExtends;
                string file = fpath + "//" + s;
                try
                {
                    myFileUpload.SaveAs(file);
                }
                catch (Exception ee)
                {
                    throw new Exception(ee.ToString());
                }
            }
            return s;
        }

        #endregion

        #region 加入文字水印

        /// <summary>
        /// 加入文字水印
        /// </summary>
        /// <param name="fileName">文件名称路径(全路径)</param>
        /// <param name="text">文件</param>
        public void AddTextToImg(string fileName, string text)
        {
            if (!File.Exists(fileName))
            {
                throw new FileNotFoundException("文件不存在");
            }
            if (text == string.Empty)
            {
                return;
            }
            //判断文件类型是否为图像类型

            System.Drawing.Image image = System.Drawing.Image.FromFile(fileName);
            Bitmap bitmap = new Bitmap(image, image.Width, image.Height);
            Graphics g = Graphics.FromImage(bitmap);
            float fontSize = 12.0f;//字体大小
            float textWidth = text.Length * fontSize;//文本的长度
            //下面定义一个矩形区域,以后在这个矩形里面画上白底黑字
            float rectX = 0;
            float rectY = 0;
            float rectWidth = text.Length * (fontSize + 8);
            float rectHeight = fontSize + 8;
            //声明矩形域
            RectangleF textArea = new RectangleF(rectX, rectY, rectWidth, rectHeight);
            Font font = new Font("宋体", fontSize);//定义字体
            Brush whiteBrush = new SolidBrush(Color.White);//白笔刷,画文字用
            Brush blackBrush = new SolidBrush(Color.Black);//黑笔刷，画背景用
            g.FillRectangle(blackBrush, rectX, rectY, rectWidth, rectHeight);
            g.DrawString(text, font, whiteBrush, textArea);
            MemoryStream ms = new MemoryStream();
            bitmap.Save(ms, ImageFormat.Jpeg);
            //输出处理后的图像，这里为了演示方便，我将图片显示在页面中了
            //Response.Clear();
            //Response.ContentType = "image/jpeg";
            //Response.BinaryWrite(ms.ToArray());
            g.Dispose();
            bitmap.Dispose();
            image.Dispose();       
        }
        #endregion
    }
}