ftp 做下载进度条

[twtyypeuxk]

我要在我的代码加上一个进度条来显示当前下载文件的进度，我应该怎么加呢？

Public Sub DownFile(ByVal Str_Path As String, ByVal Local_Path As String, ByVal Str_UserName As String, ByVal Str_Password As String)

Dim URI As String = Str_Path
Dim ftp As System.Net.FtpWebRequest = _
CType(FtpWebRequest.Create(URI), FtpWebRequest)
ftp.Credentials = New _
System.Net.NetworkCredential(Str_UserName, Str_Password)

ftp.KeepAlive = False
ftp.UseBinary = True
ftp.Method = System.Net.WebRequestMethods.Ftp.DownloadFile
Using response As System.Net.FtpWebResponse = _
CType(ftp.GetResponse, System.Net.FtpWebResponse)
Using responseStream As IO.Stream = response.GetResponseStream
'loop to read & write to file
Using fs As New IO.FileStream(Local_Path, IO.FileMode.Create)

Dim buffer(2047) As Byte
Dim read As Integer = 0
Do
read = responseStream.Read(buffer, 0, buffer.Length)
fs.Write(buffer, 0, read)
Loop Until read = 0 'see Note(1)
responseStream.Close()
fs.Flush()
fs.Close()
End Using
responseStream.Close()
End Using
response.Close()
End Using

MsgBox("下载完成", MsgBoxStyle.OkOnly + 48, "提示")
End Sub

[wangsong145]

你试试先获得文件的个数，然后把文件个数赋值给给进度条的最大值，然后从1，每循环一次，给进度条值加1

[win7cc]

进度条只是一个演示而已,他并不能代表完成下载的时间 上次看视频,里面那鸟人是这样讲的

[lizhengnan]

    Public Sub DownFile(ByVal Str_Path As String, ByVal Local_Path As String, ByVal Str_UserName As String, ByVal Str_Password As String)

        Dim URI As String = Str_Path
        Dim ftp As System.Net.FtpWebRequest = _
            CType(FtpWebRequest.Create(URI), FtpWebRequest)
        ftp.Credentials = New _
    System.Net.NetworkCredential(Str_UserName, Str_Password)

        ftp.KeepAlive = False
        ftp.UseBinary = True
        ftp.Method = System.Net.WebRequestMethods.Ftp.DownloadFile
        Using response As System.Net.FtpWebResponse = _
      CType(ftp.GetResponse, System.Net.FtpWebResponse)
            '创建进度条,把他加入FORM中
            Dim pb As New ProgressBar
            '设置最小值
            pb.Minimum = 0
            Using responseStream As IO.Stream = response.GetResponseStream

                ''设置最大值
                pb.Maximum = responseStream.Length

                'loop to read & write to file 
                Using fs As New IO.FileStream(Local_Path, IO.FileMode.Create)

                    Dim buffer(2047) As Byte
                    Dim read As Integer = 0
                    Do
                        read = responseStream.Read(buffer, 0, buffer.Length)
                        fs.Write(buffer, 0, read)

                        '每次读取的长度
                        pb.Value += buffer.Length
                    Loop Until read = 0 'see Note(1) 
                    responseStream.Close()
                    fs.Flush()
                    fs.Close()
                End Using
                responseStream.Close()
            End Using
            response.Close()
        End Using

        MsgBox("下载完成", MsgBoxStyle.OkOnly + 48, "提示")
    End Sub

[twtyypeuxk]

pb.Maximum = responseStream.Length
这一行会报错啊!
报错提示:些流不支持查找操作。

[lizhengnan]

那就要想办法知道文件的长度了.
pb.Maximum =文件的长度

[twtyypeuxk]

问题已解决！法如下!嘻

    Public Sub DFile(ByVal Str_Path As String, ByVal Local_Path As String, ByVal Str_UserName As String, ByVal Str_Password As String)

        Dim URI As String = Str_Path
        Dim ftp As System.Net.FtpWebRequest = _
            CType(FtpWebRequest.Create(URI), FtpWebRequest)
        ftp.Credentials = New _
    System.Net.NetworkCredential(Str_UserName, Str_Password)

        ftp.KeepAlive = False
        ftp.UseBinary = True
        ftp.Method = System.Net.WebRequestMethods.Ftp.DownloadFile

        Using response As System.Net.FtpWebResponse = _
      CType(ftp.GetResponse, System.Net.FtpWebResponse)
            '创建进度条,把他加入FORM中
            'Dim pb As New ProgressBar
            '设置最小值
            ProgressBar1.Minimum = 0
            Using responseStream As IO.Stream = response.GetResponseStream

                ''设置最大值
                ProgressBar1.Maximum = GetFileSize("ftp://1.1.1.1/xx.zip", "用户名", "******")
                'loop to read & write to file 
                Using fs As New IO.FileStream(Local_Path, IO.FileMode.Create)

                    Dim buffer(2047) As Byte
                    Dim read As Integer = 0
                    Do
                        read = responseStream.Read(buffer, 0, buffer.Length)
                        fs.Write(buffer, 0, read)

                        '每次读取的长度
                        If ProgressBar1.Maximum > (ProgressBar1.Value + 2047) Then
                            ProgressBar1.Value += buffer.Length
                        Else
                            ProgressBar1.Value = ProgressBar1.Maximum
                        End If

                    Loop Until read = 0 'see Note(1) 
                    responseStream.Close()
                    fs.Flush()
                    fs.Close()
                End Using
                responseStream.Close()
            End Using
            response.Close()
        End Using

        MsgBox("下载完成", MsgBoxStyle.OkOnly + 48, "提示")
    End Sub
    Public Function GetFileSize(ByVal filename As String, ByVal Str_UserName As String, ByVal Str_Password As String) As Long
        Dim URI As String = filename
        Dim ftp As System.Net.FtpWebRequest = CType(FtpWebRequest.Create(URI), FtpWebRequest)
        ftp.Credentials = New System.Net.NetworkCredential(Str_UserName, Str_Password)
        ftp.Method = WebRequestMethods.Ftp.GetFileSize
        Dim response As FtpWebResponse = ftp.GetResponse
        GetFileSize = response.ContentLength
        response.Close()
    End Function