请教，如何通过ASP.NET 代码自动弹出下载对话框下载服务器端文件(在线等)

Question

我的程序中有一个生成Excel文件的功能, 我想做成文件生成后自动弹出下载对话框供用户下载文件,
如何处理这个自动弹出下载对话框呢 ?

Answer 1

可以将生成的文件作为Stream写入Response.OutputStream，但是记住首先设置请求文件的类型为excel文件

Answer 2

string filepath = //存放文件路径;
string filename = //生成Excel文件名;
string path = filepath + filename;
Response.Clear();
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment;FileName=" + HttpUtility.UrlEncode(filename, System.Text.Encoding.UTF8));
Response.WriteFile(path);
Response.End();
放在你的生成代码后面，应该可以了

Answer 3

If System.IO.File.Exists(fileFullName) Then
 Try
            Dim myFile As New FileStream(_fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)
            Dim br As New BinaryReader(myFile)
            Try
                _Response.AddHeader("Accept-Ranges", "bytes")
                _Response.Buffer = True
                Dim fileLength As Long = myFile.Length
                Dim startBytes As Long = 0                Dim pack As Integer = 1024000 '1000K bytes
                Dim sleep As Integer = CInt(Math.Floor((1000 * pack / _speed))) + 1
                If Not (_Request.Headers("Range") Is Nothing) Then
                    _Response.StatusCode = 206
                    Dim range As String() = _Request.Headers("Range").Split(New Char() {"="c, "-"c})
                    startBytes = Convert.ToInt64(range(1))
                End If
                _Response.AddHeader("Content-Length", (fileLength - startBytes).ToString())
                If startBytes <> 0 Then
                    _Response.AddHeader("Content-Range", String.Format(" bytes {0}-{1}/{2}", startBytes, fileLength - 1, fileLength))
                End If
                _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)
                Dim maxCount As Integer = CInt(Math.Floor(((fileLength - startBytes) / pack))) + 1                Dim i As Integer
                For i = 0 To maxCount - 1
                    If _Response.IsClientConnected Then
                        _Response.BinaryWrite(br.ReadBytes(pack))
                    Else
                        i = maxCount
                    End If
                Next i
            Catch ex As Exception
                Throw New Exception(ex.ToString())
            Finally
                br.Close()
                myFile.Close()
            End Try
        Catch ex As Exception
            Throw New Exception(ex.ToString())
        End Try
        Else 
            RegisterStartupScript("filenotexist", "<script language='JavaScript'>alert('文件不存在！);</script>")
            Exit Sub
        End If