.net 下載檔案幾種方式

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方式一：TransmitFile實現下載。將指定的檔案直接寫入 HTTP 響應輸出資料流，而不在記憶體中緩衝該檔案。

protected void Button1_Click(object sender, EventArgs e)     ...{        /**//*          微軟為Response對象提供了一個新的方法TransmitFile來解決使用Response.BinaryWrite下載超過400mb的檔案時導致Aspnet_wp.exe進程回收而無法成功下載的問題。    代碼如下：    */         Response.ContentType = "application/x-zip-compressed";         Response.AddHeader("Content-Disposition", "attachment;filename=CodeShark.zip");         string filename = Server.MapPath("DownLoad/CodeShark.zip");         Response.TransmitFile(filename);     }

方式二：WriteFile實現下載，將指定的檔案直接寫入 HTTP 響應輸出資料流。注意：對大型檔案使用此方法時，調用此方法可能導致異常。可以使用此方法的檔案大小取決於 Web 服務器的硬體設定。

protected void Button2_Click(object sender, EventArgs e)    ...{        string fileName = "CodeShark.zip";//用戶端儲存的檔案名稱    string filePath = Server.MapPath("DownLoad/CodeShark.doc");//路徑    FileInfo fileInfo = new FileInfo(filePath);        Response.Clear();        Response.ClearContent();        Response.ClearHeaders();        Response.AddHeader("Content-Disposition", "attachment;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();        Response.End();    }

方式三：WriteFile分塊下載

 protected void Button3_Click(object sender, EventArgs e)    ...{        string fileName = "CodeShark.zip";//用戶端儲存的檔案名稱    string filePath = Server.MapPath("DownLoad/CodeShark.zip");//路徑   System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);        if (fileInfo.Exists == true)        ...{            const long ChunkSize = 102400;//100K 每次讀取檔案，唯讀取100Ｋ，這樣可以緩解伺服器的壓力      byte[] buffer = new byte[ChunkSize];            Response.Clear();            System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);            long dataLengthToRead = iStream.Length;//擷取下載的檔案總大小      Response.ContentType = "application/octet-stream";            Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName));            while (dataLengthToRead > 0 && Response.IsClientConnected)            ...{                int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//讀取的大小        Response.OutputStream.Write(buffer, 0, lengthRead);                Response.Flush();                dataLengthToRead = dataLengthToRead - lengthRead;            }            Response.Close();        }    }

方式四：流方式下載

 protected void Button4_Click(object sender, EventArgs e)    ...{        string fileName = "CodeShark.zip";//用戶端儲存的檔案名稱    string filePath = Server.MapPath("DownLoad/CodeShark.zip");//路徑    //以字元流的形式下載檔案    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";        //通知瀏覽器下載檔案而不是開啟    　　 Response.AddHeader("Content-Disposition", "attachment;   filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));        Response.BinaryWrite(bytes);        Response.Flush();        Response.End();    }

 

.net 下載檔案幾種方式