.NET A标签生成下载链接

最新推荐文章于 2024-05-17 10:15:10 发布

原创最新推荐文章于 2024-05-17 10:15:10 发布 · 275 阅读

0 ·

CC 4.0 BY-SA版权

C# 同时被 3 个专栏收录

33 篇文章

订阅专栏

ASP.NET

2 篇文章

订阅专栏

.NET

2 篇文章

订阅专栏

这篇博客详细介绍了如何使用C#实现HTTP文件下载功能，包括设置响应头、处理断点续传以及控制下载速度。通过Response对象与FileStream交互，确保了文件能够被正确且高效地下载。

1.A标签 href：

download.aspx?file=Filename.rar

2. download.aspx 内容：

using System.Threading;
using System.IO; 


public partial class download : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

     string filename = Request["file"].ToString();
     fileDownload(filename, Server.MapPath("~/ContractFiles/" + filename)); 
    } 
    private void fileDownload(string fileName, string fileUrl) 
    { 
        Page.Response.Clear(); 
        bool success = ResponseFile(Page.Request, Page.Response, fileName, fileUrl, 1024000);
        if (!success)
        {
            Response.Write("下载失败，请重试!");
        }
        Page.Response.End(); 
 
    } 
    public static bool ResponseFile(HttpRequest _Request, HttpResponse _Response, string _fileName, string _fullPath, long _speed) 
    { 
        try 
        { 
            FileStream myFile = new FileStream(_fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite); 
            BinaryReader br = new BinaryReader(myFile); 
            try 
            { 
                _Response.AddHeader("Accept-Ranges", "bytes"); 
                _Response.Buffer = false; 
                long fileLength = myFile.Length; 
                long startBytes = 0; 
 
                int pack = 10240; //10K bytes 
                int sleep = (int)Math.Floor((double)(1000 * pack / _speed)) + 1; 
                if (_Request.Headers["Range"] != null) 
                { 
                    _Response.StatusCode = 206; 
                    string[] range = _Request.Headers["Range"].Split(new char[] { '=', '-' }); 
                    startBytes = Convert.ToInt64(range[1]); 
                } 
                _Response.AddHeader("Content-Length", (fileLength - startBytes).ToString()); 
                if (startBytes != 0) 
                { 
                    _Response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, fileLength - 1, fileLength)); 
                } 
                _Response.AddHeader("Connection", "Keep-Alive"); 
                _Response.ContentType = "application/octet-stream"; 
                _Response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(_fileName, System.Text.Encoding.UTF8)); 
 
                br.BaseStream.Seek(startBytes, SeekOrigin.Begin); 
                int maxCount = (int)Math.Floor((double)((fileLength - startBytes) / pack)) + 1; 
 
                for (int i = 0; i < maxCount; i++) 
                { 
                    if (_Response.IsClientConnected) 
                    { 
                        _Response.BinaryWrite(br.ReadBytes(pack)); 
                        Thread.Sleep(sleep); 
                    } 
                    else 
                    { 
                        i = maxCount; 
                    } 
                } 
            } 
            catch 
            { 
                return false; 
            } 
            finally 
            { 
                br.Close(); 
                myFile.Close(); 
            } 
        } 
        catch 
        { 
            return false; 
        } 
        return true; 
    }
 
}