asp.net文件下载

2025-02-28 技术教程

switch (Convert.ToInt32(Request["type"])){ //流方式下载方法一case 1:string filename = "123.pdf";string filepath = Server.MapPath("upload/123.pdf");FileStream fs = new FileStream(filepath, FileMode.Open);byte[] bytes = new byte[(int)fs.Length];fs.Read(bytes, 0, bytes.Length);fs.Close();Response.ContentType = "application/octet-stream";Response.AddHeader("Content-Disposition", "p_w_upload; filename=" + HttpUtility.UrlEncode(filename, System.Text.Encoding.Default));Response.BinaryWrite(bytes);Response.Flush();break;case 2://方法2Response.ContentType = "application/x-zip-compressed";Response.AddHeader("Content-Disposition", "p_w_upload;filename=z.zip");string filename2 = Server.MapPath("upload/aaa.zip");Response.TransmitFile(filename2);break;case 3://方法三string fileName = "123.pdf";string filePath = Server.MapPath("upload/123.pdf");FileInfo fileInfo = new FileInfo(filePath);Response.Clear();Response.ClearContent();Response.ClearHeaders();Response.AddHeader("Content-Disposition", "p_w_upload;filename=" + fileName);Response.AddHeader("Content-Length", fileInfo.Length.ToString());Response.AddHeader("Content-Transfer-Encoding", "binary");Response.ContentType = "application/octet-stream";Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");Response.WriteFile(fileInfo.FullName);Response.Flush();break;case 4://分块下载，方法四string fileName4 = "123.pdf";string filePath5 = Server.MapPath("upload/123.pdf");System.IO.FileInfo fileInfo4 = new System.IO.FileInfo(filePath5);if (fileInfo4.Exists == true){const long ChunkSize = 1024000;//每次读取100Kbyte[] buffer = new byte[ChunkSize];Response.Clear();System.IO.FileStream iStream = System.IO.File.OpenRead(filePath5);long dataLengthToRead = iStream.Length;//获取文件长度Response.ContentType = "application/octet-stream";Response.AddHeader("Content-Disposition", "p_w_upload; filename=" + HttpUtility.UrlEncode(fileName4));while (dataLengthToRead > 0 && Response.IsClientConnected){int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));Response.OutputStream.Write(buffer, 0, lengthRead);Response.Flush();dataLengthToRead = dataLengthToRead - lengthRead;}Response.Close();}break;default:Response.Write("ddd");break;}Response.End();下载文件方法封装，怎样根据文件的扩展名下载文件（如没有扩展名，文件打开有可能出现乱码）void DownloadFile(string filename){string saveFileName = "123.xls";int intStart = filename.LastIndexOf("\\") + 1;saveFileName = filename.Substring(intStart, filename.Length - intStart);System.IO.FileInfo fi = new System.IO.FileInfo(filename);string fileextname = fi.Extension;string DEFAULT_CONTENT_TYPE = "application/unknown";RegistryKey regkey, fileextkey;string filecontenttype;try{regkey = Registry.ClassesRoot;fileextkey = regkey.OpenSubKey(fileextname);filecontenttype = fileextkey.GetValue("Content Type", DEFAULT_CONTENT_TYPE).ToString();}catch{filecontenttype = DEFAULT_CONTENT_TYPE;}Response.Clear();Response.Charset = "utf-8";Response.Buffer = true;this.EnableViewState = false;Response.ContentEncoding = System.Text.Encoding.UTF8;Response.AppendHeader("Content-Disposition", "p_w_upload;filename=" + saveFileName);Response.ContentType = filecontenttype;Response.WriteFile(filename);Response.Flush();Response.Close();Response.End();}