1// According to http://msdn2.microsoft.com/en-us/library/system.web.httppostedfile.aspx
  2// "Files are uploaded in MIME multipart/form-data format. 
  3// By default, all requests, including form fields and uploaded files, 
  4// larger than 256 KB are buffered to disk, rather than held in server memory."
  5// So we can use an HttpHandler to handle uploaded files and not have to worry
  6// about the server recycling the request do to low memory. 
  7// don't forget to increase the MaxRequestLength in the web.config.
  8// If you server is still giving errors, then something else is wrong.
  9// I've uploaded a 1.3 gig file without any problems. One thing to note, 
 10// when the SaveAs function is called, it takes time for the server to 
 11// save the file. The larger the file, the longer it takes.
 12// So if a progress bar is used in the upload, it may read 100%, but the upload won't
 13// be complete until the file is saved.  So it may look like it is stalled, but it
 14// is not.
 15
 16//该源码下载自www.51aspx.com(５１ａｓｐｘ．ｃｏｍ)
 17//5_1_a_s_p_x.c_o_m
 18
 19using System;
 20using System.Data;
 21using System.Configuration;
 22using System.Web;
 23using System.Web.Security;
 24using System.Web.UI;
 25using System.Web.UI.WebControls;
 26using System.Web.UI.WebControls.WebParts;
 27using System.Web.UI.HtmlControls;
 28using System.IO;
 29
 30/**//// <summary>
 31/// Upload handler for uploading files.
 32/// </summary>
 33public class Upload : IHttpHandler
 34...{
 35    public Upload()
 36    ...{
 37    }
 38
 39    IHttpHandler Members#region IHttpHandler Members
 40
 41    public bool IsReusable
 42    ...{
 43        get ...{ return true; }
 44    }
 45
 46    public void ProcessRequest(HttpContext context)
 47    ...{
 48        // Example of using a passed in value in the query string to set a categoryId
 49        // Now you can do anything you need to witht the file.
 50        //int categoryId = 0;
 51        //if (context.Request.QueryString["CategoryID"] != null)
 52        //{
 53        //    try
 54        //    {
 55        //        categoryId = Convert.ToInt32(context.Request.QueryString["CategoryID"]);
 56        //    }
 57        //    catch (Exception err)
 58        //    {
 59        //        categoryId = 0;
 60        //    }
 61        //}
 62        //if (categoryId > 0)
 63        //{
 64        //}
 65        
 66        if (context.Request.Files.Count > 0)
 67        ...{
 68            // get the applications path
 69            string tempFile = context.Request.PhysicalApplicationPath;
 70            // loop through all the uploaded files
 71            for(int j = 0; j < context.Request.Files.Count; j++)
 72            ...{
 73                // get the current file
 74                HttpPostedFile uploadFile = context.Request.Files[j];
 75                // if there was a file uploded
 76                if (uploadFile.ContentLength > 0)
 77                ...{
 78                    // save the file to the upload directory
 79                    
 80                    //use this if testing from a classic style upload, ie. 
 81
 82                    // <form action="Upload.axd" method="post" enctype="multipart/form-data">
 83                    //    <input type="file" name="fileUpload" />
 84                    //    <input type="submit" value="Upload" />
 85                    //</form>
 86
 87                    // this is because flash sends just the filename, where the above 
 88                    //will send the file path, ie. c:\My Pictures\test1.jpg
 89                    //you can use Test.thm to test this page.
 90                    //string filename = uploadFile.FileName.Substring(uploadFile.FileName.LastIndexOf("\\"));
 91                    //uploadFile.SaveAs(string.Format("{0}{1}{2}", tempFile, "Upload\\", filename));
 92
 93                    // use this if using flash to upload
 94                    uploadFile.SaveAs(string.Format("{0}{1}{2}", tempFile, "Upload\\", uploadFile.FileName));
 95
 96                    // HttpPostedFile has an InputStream also.  You can pass this to 
 97                    // a function, or business logic. You can save it a database:
 98
 99                    //byte[] fileData = new byte[uploadFile.ContentLength];
100                    //uploadFile.InputStream.Write(fileData, 0, fileData.Length);
101                    // save byte array into database.
102
103                    // something I do is extract files from a zip file by passing
104                    // the inputStream to a function that uses SharpZipLib found here:
105                    // http://www.icsharpcode.net/OpenSource/SharpZipLib/
106                    // and then save the files to disk.                    
107                }                
108            }
109        }
110        // Used as a fix for a bug in mac flash player that makes the 
111        // onComplete event not fire
112        HttpContext.Current.Response.Write(" ");
113    }
114
115    #endregion
116}
117