使用ASP.net（C#）批量上传图片并自动生成缩略图,文字水印图,图片水印图

因本网站上传图片的需要，参考很多成熟的经验，在ASP.net平台上使用C#语言，做了这一自动批量上传图片的.ASPX文件，并经调试成功，在本网站上使用，现发出来供大家参考，也希望高手多加指点。 

        本程序主要功能有： 

        （1）可以根据自己的需要更改上传到服务器上的目录，上传的源图、缩略图、文字水印图和图片水印图分别存入所定目录下的不同目录； 

        （2）自动检查目录，如无所选择的目录，则自动创建它们； 

        （3）自行设定生成缩略图的大小； 

        （4）可以选择是否需要生成文字水印、图片水印，默认为不生成水印图； 

        （5）可以添加、删除所需上传的图片。 

        在本程序中均加了相关注释，所以直接发代码，不再多作解释。 

后台程序： 

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.IO;
using System.Net;
using System.Text.RegularExpressions;

/// <summary>
/// FileUpload1.HasFile  如果是true，则表示该控件有文件要上传
/// FileUpload1.FileName  返回要上传文件的名称，不包含路径信息
/// FileUpload1.FileContent  返回一个指向上传文件的流对象
/// FileUpload1.PostedFile   返回已经上传文件的引用
/// FileUpload1.PostedFile.ContentLength  返回上传文件的按字节表示的文件大小
/// FileUpload1.PostedFile.ContentType    返回上传文件的MIME内容类型，也就是文件类型，如返回"image/jpg"
/// FileUpload1.PostedFile.FileName       返回文件在客户端的完全路径（包括文件名全称）
/// FileUpload1.PostedFile.InputStream    返回一个指向上传文件的流对象
/// FileInfo对象表示磁盘或网络位置上的文件。提供文件的路径，就可以创建一个FileInfo对象：
/// </summary>

public partial class BackManagement_ImagesUpload : System.Web.UI.Page
{
    public string treePath = "";
    public int imageW = 100;
    public int imageH = 100;
    protected void Page_Load(object sender, EventArgs e)
    {
        this.Button5.Attributes.Add("Onclick", "window.close();"); //在本地关闭当前页，而不需要发送到服务器去关闭当前页时
        if (!Page.IsPostBack)
        {
            Label2.Text = Server.MapPath("/");
            TextBox3.Text = "ImageUpload";
            treePath = Server.MapPath("/") + TextBox3.Text.Trim() + "/";
            TextBox4.Text = imageW.ToString();
            TextBox5.Text = imageH.ToString();
        }
    }
    protected void btnload_Click(object sender, EventArgs e)
    {
        //如果保存图片的目录不存在，由创建它
        treePath = Server.MapPath("/") + TextBox3.Text.Trim() + "/";
        imageW = Convert.ToInt32(TextBox4.Text.ToString());
        imageH = Convert.ToInt32(TextBox5.Text.ToString());
        if (!File.Exists(treePath + "images"))   //如果/ImageUpload/images不存在，则创建/ImageUpload/images，用于存放源图片
        {
            System.IO.Directory.CreateDirectory(treePath + "images");
        }
        if (!File.Exists(treePath + "thumbnails"))   //如果/ImageUpload/thumbnails不存在，则创建/ImageUpload/thumbnails，用于存放缩略图片
        {
            System.IO.Directory.CreateDirectory(treePath + "thumbnails");
        }
        if (!File.Exists(treePath + "textImages"))   //如果/ImageUpload/textImages不存在，则创建/ImageUpload/textImages，用于存文字水印图片
        {
            System.IO.Directory.CreateDirectory(treePath + "textImages");
        }
        if (!File.Exists(treePath + "waterImages"))   //如果/ImageUpload/waterImages不存在，则创建/ImageUpload/waterImages，用于存图形水印图片
        {
            System.IO.Directory.CreateDirectory(treePath + "waterImages");
        }

        if (FileUpload1.HasFile)   //如果是true，则表示该控件有文件要上传
        {
            string fileContentType = FileUpload1.PostedFile.ContentType;
            if (fileContentType == "image/bmp" || fileContentType == "image/gif" || fileContentType == "image/pjpeg")
            {
                string name = FileUpload1.PostedFile.FileName;                         //返回文件在客户端的完全路径（包括文件名全称）

                FileInfo file = new FileInfo(name);                                    //FileInfo对象表示磁盘或网络位置上的文件。提供文件的路径，就可以创建一个FileInfo对象：
                string fileName = file.Name;                                           // 文件名称
                string fileName_s = "x_" + file.Name;                                  // 缩略图文件名称
                string fileName_sy = "text_" + file.Name;                              // 水印图文件名称（文字）
                string fileName_syp = "water_" + file.Name;                            // 水印图文件名称（图片）

                string webFilePath = treePath + "images/" + fileName;          // 服务器端文件路径
                string webFilePath_s = treePath + "thumbnails/" + fileName_s;　　  // 服务器端缩略图路径
                string webFilePath_sy = treePath + "textImages/" + fileName_sy;　  // 服务器端带水印图路径(文字)
                string webFilePath_syp = treePath + "waterImages/" + fileName_syp;　// 服务器端带水印图路径(图片)
                string webFilePath_sypf = Server.MapPath("../images/tzwhx.png");　              // 服务器端水印图路径(图片)

                if (!File.Exists(webFilePath))
                {
                    try
                    {
                        FileUpload1.SaveAs(webFilePath);                                // 使用 SaveAs 方法保存文件
                        if (CheckBox1.Checked)                                          //是否生成文字水印图
                        {
                            AddWater(webFilePath, webFilePath_sy);
                        }
                        if (CheckBox2.Checked)                                          //是否生成图形水印图
                        {
                            AddWaterPic(webFilePath, webFilePath_syp, webFilePath_sypf);
                        }
                        MakeThumbnail(webFilePath, webFilePath_s, imageW, imageH, "Cut");     // 生成缩略图方法
                        Label1.Text = "提示：文件“" + fileName + "”成功上传，并生成“" + fileName_s + "”缩略图，文件类型为：" + FileUpload1.PostedFile.ContentType + "，文件大小为：" + FileUpload1.PostedFile.ContentLength + "B";
                        Image1.ImageUrl = "/" + TextBox3.Text.ToString() + "/images/" + fileName;
                        TextBox1.Text = webFilePath;
                        TextBox2.Text = "/" + TextBox3.Text.ToString() + "/images/" + fileName;
                    }
                    catch (Exception ex)
                    {
                        Label1.Text = "提示：文件上传失败，失败原因：" + ex.Message;
                    }
                }
                else
                {
                    Label1.Text = "提示：文件已经存在，请重命名后上传";
                }
            }
            else
            {
                Label1.Text = "提示：文件类型不符";
            }
        }
    }
    /**/
    /// <summary>
    /// 生成缩略图
    /// </summary>
    /// <param name="originalImagePath">源图路径（物理路径）</param>
    /// <param name="thumbnailPath">缩略图路径（物理路径）</param>
    /// <param name="width">缩略图宽度</param>
    /// <param name="height">缩略图高度</param>
    /// <param name="mode">生成缩略图的方式</param>
    public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
    {
        System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);

        int towidth = width;
        int toheight = height;

        int x = 0;
        int y = 0;
        int ow = originalImage.Width;
        int oh = originalImage.Height;

        switch (mode)
        {
            case "HW"://指定高宽缩放（可能变形）
                break;
            case "W"://指定宽，高按比例
                toheight = originalImage.Height * width / originalImage.Width;
                break;
            case "H"://指定高，宽按比例
                towidth = originalImage.Width * height / originalImage.Height;
                break;
            case "Cut"://指定高宽裁减（不变形）
                if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
{

                    oh = originalImage.Height;
                    ow = originalImage.Height * towidth / toheight;
                    y = 0;
                    x = (originalImage.Width - ow) / 2;
                } else
                {
                    ow = originalImage.Width;
                    oh = originalImage.Width * height / towidth;
                    x = 0;
                    y = (originalImage.Height - oh) / 2;
                }
                break;
            default:
                break;
        }

        //新建一个bmp图片
        System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);

        //新建一个画板
        System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);

        //设置高质量插值法
        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

        //设置高质量,低速度呈现平滑程度
        g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

        //清空画布并以透明背景色填充
        g.Clear(System.Drawing.Color.Transparent);

        //在指定位置并且按指定大小绘制原图片的指定部分
        g.DrawImage(originalImage, new System.Drawing.Rectangle(0, 0, towidth, toheight),
            new System.Drawing.Rectangle(x, y, ow, oh),
            System.Drawing.GraphicsUnit.Pixel);

        try
        {
            //以jpg格式保存缩略图
            bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
        }
        catch (System.Exception e)
        {
            throw e;
        }
        finally
        {
            originalImage.Dispose();
            bitmap.Dispose();
            g.Dispose();
        }
    }

    /**/
    /// <summary>
    /// 在图片上增加文字水印
    /// </summary>
    /// <param name="Path">原服务器图片路径</param>
    /// <param name="Path_sy">生成的带文字水印的图片路径</param>
    protected void AddWater(string Path, string Path_sy)
    {
        string addText = "www.tzwhx.com";
        System.Drawing.Image image = System.Drawing.Image.FromFile(Path);
        System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);
        g.DrawImage(image, 0, 0, image.Width, image.Height);
        System.Drawing.Font f = new System.Drawing.Font("Verdana", 10);    //字体位置为左空10
        System.Drawing.Brush b = new System.Drawing.SolidBrush(System.Drawing.Color.Green);

        g.DrawString(addText, f, b, 14, 14);    //字体大小为14X14
        g.Dispose();

        image.Save(Path_sy);
        image.Dispose();
    }

    /**/
    /// <summary>
    /// 在图片上生成图片水印
    /// </summary>
    /// <param name="Path">原服务器图片路径</param>
    /// <param name="Path_syp">生成的带图片水印的图片路径</param>
    /// <param name="Path_sypf">水印图片路径</param>
    protected void AddWaterPic(string Path, string Path_syp, string Path_sypf)
    {
        System.Drawing.Image image = System.Drawing.Image.FromFile(Path);
        System.Drawing.Image copyImage = System.Drawing.Image.FromFile(Path_sypf);
        System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);
        g.DrawImage(copyImage, new System.Drawing.Rectangle(image.Width - copyImage.Width, image.Height - copyImage.Height, copyImage.Width, copyImage.Height), 0, 0, copyImage.Width, copyImage.Height, System.Drawing.GraphicsUnit.Pixel);
        g.Dispose();

        image.Save(Path_syp);
        image.Dispose();
    }

    protected void Button2_Click(object sender, EventArgs e)
    {
        //自动保存远程图片
         WebClient client = new WebClient();
        //备用Reg:<img.*?src=([\"\'])(http:\/\/.+\.(jpg|gif|bmp|bnp))\1.*?>
        Regex reg = new Regex("IMG[^>]*?src\\s*=\\s*(?:\"(?<1>[^\"]*)\"|'(?<1>[^\']*)')", RegexOptions.IgnoreCase);
        MatchCollection m = reg.Matches(TextBox1.Text);

        foreach (Match math in m)
        {
            string imgUrl = math.Groups[1].Value;

            //在原图片名称前加YYMMDD重名名并上传

              Regex regName = new Regex(@"\w+.(?:jpg|gif|bmp|png)", RegexOptions.IgnoreCase);

            string strNewImgName = DateTime.Now.ToShortDateString().Replace("-", "") + regName.Match(imgUrl).ToString();

            try
            {
              //保存图片
                //client.DownloadFile(imgUrl, Server.MapPath("../ImageUpload/Auto/" + strNewImgName));

            }
            catch
            {
            }
            finally
            {
            }
            client.Dispose();
        }
        Response.Write("<mce:script type="text/javascript"><!--
alert('远程图片保存成功，保存路径为ImageUpload/auto')
// --></mce:script>");
    }
}
using System; 
using System.Collections; 
using System.Configuration; 
using System.Data; 
using System.Linq; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.HtmlControls; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Xml.Linq; 
using System.IO; 
using System.Net; 
using System.Text.RegularExpressions; 

/// <summary> 
/// FileUpload1.HasFile  如果是true，则表示该控件有文件要上传 
/// FileUpload1.FileName  返回要上传文件的名称，不包含路径信息 
/// FileUpload1.FileContent  返回一个指向上传文件的流对象 
/// FileUpload1.PostedFile   返回已经上传文件的引用 
/// FileUpload1.PostedFile.ContentLength  返回上传文件的按字节表示的文件大小 
/// FileUpload1.PostedFile.ContentType    返回上传文件的MIME内容类型，也就是文件类型，如返回"image/jpg" 
/// FileUpload1.PostedFile.FileName       返回文件在客户端的完全路径（包括文件名全称） 
/// FileUpload1.PostedFile.InputStream    返回一个指向上传文件的流对象 
/// FileInfo对象表示磁盘或网络位置上的文件。提供文件的路径，就可以创建一个FileInfo对象： 
/// </summary> 

public partial class BackManagement_ImagesUpload : System.Web.UI.Page 
{ 
    public string treePath = ""; 
    public int imageW = 100; 
    public int imageH = 100; 
    protected void Page_Load(object sender, EventArgs e) 
    { 
        this.Button5.Attributes.Add("Onclick", "window.close();"); //在本地关闭当前页，而不需要发送到服务器去关闭当前页时 
        if (!Page.IsPostBack) 
        { 
            Label2.Text = Server.MapPath("/"); 
            TextBox3.Text = "ImageUpload"; 
            treePath = Server.MapPath("/") + TextBox3.Text.Trim() + "/"; 
            TextBox4.Text = imageW.ToString(); 
            TextBox5.Text = imageH.ToString(); 
        } 
    } 
    protected void btnload_Click(object sender, EventArgs e) 
    { 
        //如果保存图片的目录不存在，由创建它 
        treePath = Server.MapPath("/") + TextBox3.Text.Trim() + "/"; 
        imageW = Convert.ToInt32(TextBox4.Text.ToString()); 
        imageH = Convert.ToInt32(TextBox5.Text.ToString()); 
        if (!File.Exists(treePath + "images"))   //如果/ImageUpload/images不存在，则创建/ImageUpload/images，用于存放源图片 
        { 
            System.IO.Directory.CreateDirectory(treePath + "images"); 
        } 
        if (!File.Exists(treePath + "thumbnails"))   //如果/ImageUpload/thumbnails不存在，则创建/ImageUpload/thumbnails，用于存放缩略图片 
        { 
            System.IO.Directory.CreateDirectory(treePath + "thumbnails"); 
        } 
        if (!File.Exists(treePath + "textImages"))   //如果/ImageUpload/textImages不存在，则创建/ImageUpload/textImages，用于存文字水印图片 
        { 
            System.IO.Directory.CreateDirectory(treePath + "textImages"); 
        } 
        if (!File.Exists(treePath + "waterImages"))   //如果/ImageUpload/waterImages不存在，则创建/ImageUpload/waterImages，用于存图形水印图片 
        { 
            System.IO.Directory.CreateDirectory(treePath + "waterImages"); 
        } 

        if (FileUpload1.HasFile)   //如果是true，则表示该控件有文件要上传 
        { 
            string fileContentType = FileUpload1.PostedFile.ContentType; 
            if (fileContentType == "image/bmp" || fileContentType == "image/gif" || fileContentType == "image/pjpeg") 
            { 
                string name = FileUpload1.PostedFile.FileName;                         //返回文件在客户端的完全路径（包括文件名全称） 

                FileInfo file = new FileInfo(name);                                    //FileInfo对象表示磁盘或网络位置上的文件。提供文件的路径，就可以创建一个FileInfo对象： 
                string fileName = file.Name;                                           // 文件名称 
                string fileName_s = "x_" + file.Name;                                  // 缩略图文件名称 
                string fileName_sy = "text_" + file.Name;                              // 水印图文件名称（文字） 
                string fileName_syp = "water_" + file.Name;                            // 水印图文件名称（图片） 

                string webFilePath = treePath + "images/" + fileName;          // 服务器端文件路径 
                string webFilePath_s = treePath + "thumbnails/" + fileName_s;　　  // 服务器端缩略图路径 
                string webFilePath_sy = treePath + "textImages/" + fileName_sy;　  // 服务器端带水印图路径(文字) 
                string webFilePath_syp = treePath + "waterImages/" + fileName_syp;　// 服务器端带水印图路径(图片) 
                string webFilePath_sypf = Server.MapPath("../images/tzwhx.png");　              // 服务器端水印图路径(图片) 
                 
                if (!File.Exists(webFilePath)) 
                { 
                    try 
                    { 
                        FileUpload1.SaveAs(webFilePath);                                // 使用 SaveAs 方法保存文件 
                        if (CheckBox1.Checked)                                          //是否生成文字水印图 
                        { 
                            AddWater(webFilePath, webFilePath_sy); 
                        } 
                        if (CheckBox2.Checked)                                          //是否生成图形水印图 
                        { 
                            AddWaterPic(webFilePath, webFilePath_syp, webFilePath_sypf); 
                        } 
                        MakeThumbnail(webFilePath, webFilePath_s, imageW, imageH, "Cut");     // 生成缩略图方法 
                        Label1.Text = "提示：文件“" + fileName + "”成功上传，并生成“" + fileName_s + "”缩略图，文件类型为：" + FileUpload1.PostedFile.ContentType + "，文件大小为：" + FileUpload1.PostedFile.ContentLength + "B"; 
                        Image1.ImageUrl = "/" + TextBox3.Text.ToString() + "/images/" + fileName; 
                        TextBox1.Text = webFilePath; 
                        TextBox2.Text = "/" + TextBox3.Text.ToString() + "/images/" + fileName; 
                    } 
                    catch (Exception ex) 
                    { 
                        Label1.Text = "提示：文件上传失败，失败原因：" + ex.Message; 
                    } 
                } 
                else 
                { 
                    Label1.Text = "提示：文件已经存在，请重命名后上传"; 
                } 
            } 
            else 
            { 
                Label1.Text = "提示：文件类型不符"; 
            } 
        } 
    } 
    /**/ 
    /// <summary> 
    /// 生成缩略图 
    /// </summary> 
    /// <param name="originalImagePath">源图路径（物理路径）</param> 
    /// <param name="thumbnailPath">缩略图路径（物理路径）</param> 
    /// <param name="width">缩略图宽度</param> 
    /// <param name="height">缩略图高度</param> 
    /// <param name="mode">生成缩略图的方式</param>     
    public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode) 
    { 
        System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath); 

        int towidth = width; 
        int toheight = height; 

        int x = 0; 
        int y = 0; 
        int ow = originalImage.Width; 
        int oh = originalImage.Height; 

        switch (mode) 
        { 
            case "HW"://指定高宽缩放（可能变形）                 
                break; 
            case "W"://指定宽，高按比例                     
                toheight = originalImage.Height * width / originalImage.Width; 
                break; 
            case "H"://指定高，宽按比例 
                towidth = originalImage.Width * height / originalImage.Height; 
                break; 
            case "Cut"://指定高宽裁减（不变形）                 
                if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
{ 

                    oh = originalImage.Height; 
                    ow = originalImage.Height * towidth / toheight; 
                    y = 0; 
                    x = (originalImage.Width - ow) / 2; 
                } else 
                { 
                    ow = originalImage.Width; 
                    oh = originalImage.Width * height / towidth; 
                    x = 0; 
                    y = (originalImage.Height - oh) / 2; 
                } 
                break; 
            default: 
                break; 
        } 

        //新建一个bmp图片 
        System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight); 

        //新建一个画板 
        System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap); 

        //设置高质量插值法 
        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; 

        //设置高质量,低速度呈现平滑程度 
        g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; 

        //清空画布并以透明背景色填充 
        g.Clear(System.Drawing.Color.Transparent); 

        //在指定位置并且按指定大小绘制原图片的指定部分 
        g.DrawImage(originalImage, new System.Drawing.Rectangle(0, 0, towidth, toheight), 
            new System.Drawing.Rectangle(x, y, ow, oh), 
            System.Drawing.GraphicsUnit.Pixel); 

        try 
        { 
            //以jpg格式保存缩略图 
            bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg); 
        } 
        catch (System.Exception e) 
        { 
            throw e; 
        } 
        finally 
        { 
            originalImage.Dispose(); 
            bitmap.Dispose(); 
            g.Dispose(); 
        } 
    } 

    /**/ 
    /// <summary> 
    /// 在图片上增加文字水印 
    /// </summary> 
    /// <param name="Path">原服务器图片路径</param> 
    /// <param name="Path_sy">生成的带文字水印的图片路径</param> 
    protected void AddWater(string Path, string Path_sy) 
    { 
        string addText = "www.tzwhx.com"; 
        System.Drawing.Image image = System.Drawing.Image.FromFile(Path); 
        System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image); 
        g.DrawImage(image, 0, 0, image.Width, image.Height); 
        System.Drawing.Font f = new System.Drawing.Font("Verdana", 10);    //字体位置为左空10 
        System.Drawing.Brush b = new System.Drawing.SolidBrush(System.Drawing.Color.Green); 

        g.DrawString(addText, f, b, 14, 14);    //字体大小为14X14 
        g.Dispose(); 

        image.Save(Path_sy); 
        image.Dispose(); 
    } 

    /**/ 
    /// <summary> 
    /// 在图片上生成图片水印 
    /// </summary> 
    /// <param name="Path">原服务器图片路径</param> 
    /// <param name="Path_syp">生成的带图片水印的图片路径</param> 
    /// <param name="Path_sypf">水印图片路径</param> 
    protected void AddWaterPic(string Path, string Path_syp, string Path_sypf) 
    { 
        System.Drawing.Image image = System.Drawing.Image.FromFile(Path); 
        System.Drawing.Image copyImage = System.Drawing.Image.FromFile(Path_sypf); 
        System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image); 
        g.DrawImage(copyImage, new System.Drawing.Rectangle(image.Width - copyImage.Width, image.Height - copyImage.Height, copyImage.Width, copyImage.Height), 0, 0, copyImage.Width, copyImage.Height, System.Drawing.GraphicsUnit.Pixel); 
        g.Dispose(); 

        image.Save(Path_syp); 
        image.Dispose(); 
    } 

    protected void Button2_Click(object sender, EventArgs e) 
    { 
        //自动保存远程图片 
         WebClient client = new WebClient(); 
        //备用Reg:<img.*?src=([\"\'])(http:\/\/.+\.(jpg|gif|bmp|bnp))\1.*?> 
        Regex reg = new Regex("IMG[^>]*?src\\s*=\\s*(?:\"(?<1>[^\"]*)\"|'(?<1>[^\']*)')", RegexOptions.IgnoreCase); 
        MatchCollection m = reg.Matches(TextBox1.Text); 

        foreach (Match math in m) 
        { 
            string imgUrl = math.Groups[1].Value; 

            //在原图片名称前加YYMMDD重名名并上传 

              Regex regName = new Regex(@"\w+.(?:jpg|gif|bmp|png)", RegexOptions.IgnoreCase); 

            string strNewImgName = DateTime.Now.ToShortDateString().Replace("-", "") + regName.Match(imgUrl).ToString(); 

            try 
            { 
              //保存图片 
                //client.DownloadFile(imgUrl, Server.MapPath("../ImageUpload/Auto/" + strNewImgName)); 
                 
            } 
            catch 
            { 
            } 
            finally 
            {
            }
            client.Dispose(); 
        } 
        Response.Write("<mce:script type="text/javascript"><!--
alert('远程图片保存成功，保存路径为ImageUpload/auto')
// --></mce:script>"); 
    } 
} 


前台代码：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ImagesAutoUpload.aspx.cs" Inherits="BackManagement_ImagesAutoUpload" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>自动上传图片并加文字水印</title>
</head>
<body>
    <form id="form1" runat="server" method="post" enctype="multipart/form-data">
    <label for="pagebody1" style="display: none" mce_style="display: none">
    </label>
    <fieldset id="container">
        <legend>上传图片并加文字水印</legend>
        <div class="window" style="list-style: none;" mce_style="list-style: none;">
            <div style="padding: 0px; width: 808px; height: 200px; float: left; margin-right: 0px;">
                <ul>
                    <li style="width: 150px; margin: 0px; padding: 0px; float: left;">
                        <asp:Image ID="Image1" runat="server" Heig, ht="200px" BorderWidth="2px" Width="150px"
                            ImageUrl="~/images/Jpg/135X67/0_11_16.gif" />
                    </li>
                    <li style="width: 250px; margin: 0px;">
                        <asp:ListBox ID="FileList" runat="server" Width="250px" Height="200px"></asp:ListBox>
                    </li>
                    <li style="width: 400px; margin: 0px; float: right;">
                        (1)图片将保存在你网站根目录<asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>中，你可以修改它，但建议你使用默认目录。<br />
                        (2)上传图片保存在所建目录的子目录 /images下；缩略图在 /thumbnails下；文字水印图在 /textImages下；图形水印图在 /waterImages目录下。<br />
                        (3)生成的缩略图的默认宽度和高度均为100px，你也可以修改它们，宽为： <asp:TextBox ID="TextBox4" runat="server" Width="54px"></asp:TextBox>高为：<asp:TextBox
                            ID="TextBox5" runat="server" Width="56px"></asp:TextBox><br />
                        <asp:CheckBox ID="CheckBox1" runat="server" Text="文字水印" />
                        <asp:CheckBox ID="CheckBox2" runat="server" Text="图形水印" />
                            你可以选择是否生成水印图，默认不生成。 </li>
                </ul>
            </div>
        </div>
        <div>
            <asp:FileUpload ID="FindFile" runat="server" Width="529px" />
        </div>
        <div>
            <asp:TextBox ID="TipInfo" runat="server" Width="400px"></asp:TextBox>
            <asp:TextBox ID="TextBox1" runat="server" Width="400px"></asp:TextBox>
        </div>
        <div>
            <asp:Button ID="Upload" runat="server" Text="上  传" Style="height: 26px" mce_Style="height: 26px" OnClick="Upload_Click" />
            <asp:Button ID="AddFile" runat="server" Text="添  加" OnClick="AddFile_Click1" />
            <asp:Button ID="AddAllFile" runat="server" Text="全部添加" OnClick="AddAllFile_Click"
                Enabled="False" />
            <asp:Button ID="DelFile" runat="server" Text="删  除" OnClick="DelFile_Click1" />
            <asp:Button ID="btnExit" runat="server" Text="完  成" />
        </div>
        <div>

        </div>
    </fieldset>
    </form>
</body>
</html>
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ImagesAutoUpload.aspx.cs" Inherits="BackManagement_ImagesAutoUpload" %> 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 

<html xmlns="http://www.w3.org/1999/xhtml"> 
<head id="Head1" runat="server"> 
    <title>自动上传图片并加文字水印</title> 
</head> 
<body> 
    <form id="form1" runat="server" method="post" enctype="multipart/form-data"> 
    <label for="pagebody1" style="display: none" mce_style="display: none"> 
    </label> 
    <fieldset id="container"> 
        <legend>上传图片并加文字水印</legend> 
        <div class="window" style="list-style: none;" mce_style="list-style: none;"> 
            <div style="padding: 0px; width: 808px; height: 200px; float: left; margin-right: 0px;"> 
                <ul> 
                    <li style="width: 150px; margin: 0px; padding: 0px; float: left;"> 
                        <asp:Image ID="Image1" runat="server" Heig, ht="200px" BorderWidth="2px" Width="150px" 
                            ImageUrl="~/images/Jpg/135X67/0_11_16.gif" /> 
                    </li> 
                    <li style="width: 250px; margin: 0px;"> 
                        <asp:ListBox ID="FileList" runat="server" Width="250px" Height="200px"></asp:ListBox> 
                    </li> 
                    <li style="width: 400px; margin: 0px; float: right;"> 
                        (1)图片将保存在你网站根目录<asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>中，你可以修改它，但建议你使用默认目录。<br /> 
                        (2)上传图片保存在所建目录的子目录 /images下；缩略图在 /thumbnails下；文字水印图在 /textImages下；图形水印图在 /waterImages目录下。<br /> 
                        (3)生成的缩略图的默认宽度和高度均为100px，你也可以修改它们，宽为： <asp:TextBox ID="TextBox4" runat="server" Width="54px"></asp:TextBox>高为：<asp:TextBox 
                            ID="TextBox5" runat="server" Width="56px"></asp:TextBox><br /> 
                        <asp:CheckBox ID="CheckBox1" runat="server" Text="文字水印" /> 
                        <asp:CheckBox ID="CheckBox2" runat="server" Text="图形水印" /> 
                            你可以选择是否生成水印图，默认不生成。 </li> 
                </ul> 
            </div> 
        </div> 
        <div> 
            <asp:FileUpload ID="FindFile" runat="server" Width="529px" /> 
        </div> 
        <div> 
            <asp:TextBox ID="TipInfo" runat="server" Width="400px"></asp:TextBox> 
            <asp:TextBox ID="TextBox1" runat="server" Width="400px"></asp:TextBox> 
        </div> 
        <div> 
            <asp:Button ID="Upload" runat="server" Text="上  传" Style="height: 26px" mce_Style="height: 26px" OnClick="Upload_Click" /> 
            <asp:Button ID="AddFile" runat="server" Text="添  加" OnClick="AddFile_Click1" /> 
            <asp:Button ID="AddAllFile" runat="server" Text="全部添加" OnClick="AddAllFile_Click" 
                Enabled="False" /> 
            <asp:Button ID="DelFile" runat="server" Text="删  除" OnClick="DelFile_Click1" /> 
            <asp:Button ID="btnExit" runat="server" Text="完  成" /> 
        </div> 
        <div> 
             
        </div> 
    </fieldset> 
    </form> 
</body> 
</html> 


另外，为解决大文件上传的限制，你必须在Web.config中加入以下代码。

<system.web>
    <httpRuntime executionTimeout="90" maxRequestLength="20000" useFullyQualifiedRedirectUrl="false" requestLengthDiskThreshold="8192"/>
</system.web>
<system.web> 
    <httpRuntime executionTimeout="90" maxRequestLength="20000" useFullyQualifiedRedirectUrl="false" requestLengthDiskThreshold="8192"/> 
</system.web>




文章出处：http://www.diybl.com/course/4_webprogram/asp.net/asp_netxl/2008106/148796_3.html