Question

请参阅下面的处理程序：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace FileExplorer
{
    /// <summary>
    /// Summary description for HandlerForMyFE
    /// </summary>
    public class HandlerForMyFE : IHttpHandler, System.Web.SessionState.IRequiresSessionState
    {

        private HttpContext _context;
        private HttpContext Context
        {
            get
            {
                return _context;
            }
            set
            {
                _context = value;
            }
        }

        public void ProcessRequest(HttpContext context)
        {
            Context = context;
            string filePath = context.Request.QueryString["Downloadpath"];
            filePath = context.Server.MapPath(filePath);

            if (filePath == null)
            {
                return;
            }

            System.IO.StreamReader streamReader = new System.IO.StreamReader(filePath);
            System.IO.BinaryReader br = new System.IO.BinaryReader(streamReader.BaseStream);

            byte[] bytes = new byte[streamReader.BaseStream.Length];

            br.Read(bytes, 0, (int)streamReader.BaseStream.Length);

            if (bytes == null)
            {
                return;
            }

            streamReader.Close();
            br.Close();
            string fileName = System.IO.Path.GetFileName(filePath);
            string MimeType = GetMimeType(fileName);
            string extension = System.IO.Path.GetExtension(filePath);
            char[] extension_ar = extension.ToCharArray();
            string extension_Without_dot = string.Empty;
            for (int i = 1; i < extension_ar.Length; i++)
            {
                extension_Without_dot += extension_ar[i];
            }

            //if (extension == ".jpg")
            //{ // Handle *.jpg and
            //    WriteFile(bytes, fileName, "image/jpeg jpeg jpg jpe", context.Response);
            //}
            //else if (extension == ".gif")
            //{// Handle *.gif
            //    WriteFile(bytes, fileName, "image/gif gif", context.Response);
            //}

            WriteFile(bytes, fileName, MimeType + " " + extension_Without_dot, context.Response);
        }

        private void WriteFile(byte[] content, string fileName, string contentType, HttpResponse response)
        {
            response.Buffer = true;
            response.Clear();
            response.ContentType = contentType;

            response.AddHeader("content-disposition", "attachment; filename=" + fileName);

            response.BinaryWrite(content);
            response.Flush();
            response.End();
        }

        private string GetMimeType(string fileName)
        {
            string mimeType = "application/unknown";
            string ext = System.IO.Path.GetExtension(fileName).ToLower();
            Microsoft.Win32.RegistryKey regKey = Microsoft.Win32.Registry.ClassesRoot.OpenSubKey(ext);
            if (regKey != null && regKey.GetValue("Content Type") != null)
                mimeType = regKey.GetValue("Content Type").ToString();
            return mimeType;
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}

我在点击后没有在浏览器中打开该文件就写了直接下载文件的处理程序...
似乎上面的代码工作！
但是在下载过程中显示文件大小存在问题测试，请参阅以下链接：
Test with internet download manager
在该链接中，我们没有文件大小，但在下面的链接中我们有它：
another link
我的处理程序有什么问题？如何解决这个问题？

提前致谢

Answer 1

我没有运行此代码。这是传输文件的另一种方式。

试试这段代码：

//context = HttpContext
context.Response.Clear();
context.Response.ContentType = varMimeType;
context.Response.TransmitFile(filePath);
context.Response.AddHeader("content-disposition", "attachment;filename=" + varFileName);
context.Response.AddHeader("Content-Length", filePathFileInfo.Length);
context.Response.Flush();
context.Response.End();

直接文件下载而不是打开处理程序 - 文件大小显示问题

1 个答案: