Question FTP Downloaded file corrupt

liey87

New member
Joined
Nov 12, 2013
Messages
3
Programming Experience
3-5
I want to download all file that located on FTP site. I break into 2 operations. First is to get the list of all files in the directory. Then I proceed to second which download each file. But unfortunately, the downloaded file is corrupt. Worst over, it affect the file on FTP folder. Both folder contains corrupt file. From a viewing thumbnails image to default image thumbnails. How this happen and to overcome this? Below are my code; full code class. I provide as reference and guide to do a correct way :)

Private strTargetPath As String
Private strDestPath As String

Private Sub frmLoader_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Try
objSQL = New clsSQL
If objSQL.SQLGetAllData Then 'Get data from SQL and insert into an arraylist
strTargetPath = "ftp://192.168.1.120/image/"
strDestPath = "D:\Application\FTPImg\"
ListFileFromFTP()
End If
Catch ex As Exception
strErrMsg = "Oops! Something is wrong with loading login form."
MessageBox.Show(strErrMsg & vbCrLf & "ExMsg: " & ex.Message, "Error message!", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
End Sub
Private Sub ListFileFromFTP()
Dim arrFile As ArrayList
Dim strPath As String
Try
Dim reqFTP As FtpWebRequest
reqFTP = FtpWebRequest.Create(New Uri(strTargetPath))
reqFTP.UseBinary = True
reqFTP.Credentials = New NetworkCredential("user", "user123")
reqFTP.Method = WebRequestMethods.Ftp.ListDirectory
reqFTP.Proxy = Nothing
reqFTP.KeepAlive = False
reqFTP.UsePassive = False
Dim response As FtpWebResponse = DirectCast(reqFTP.GetResponse(), FtpWebResponse)
Dim sr As StreamReader
sr = New StreamReader(reqFTP.GetResponse().GetResponseStream())
Dim FileListing As String = sr.ReadLine
arrFile = New ArrayList
While FileListing <> Nothing
strPath = strTargetPath & FileListing
arrFile.Add(strPath)
FileListing = sr.ReadLine
End While
sr.Close()
sr = Nothing
reqFTP = Nothing
response.Close()
For i = 0 To (arrFile.Count - 1)
DownloadImage(arrFile.Item(i))
Next
Catch ex As Exception
strErrMsg = "Oops! Something is wrong with ListFileFromFTP."
MessageBox.Show(strErrMsg & vbCrLf & "ExMsg: " & ex.Message, "Error message!", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
End Sub
Public Function DownloadImage(ByVal strName As String) As String
Dim ftp_request As FtpWebRequest = Nothing
Dim ftpStream As Stream = Nothing

Dim strOldName As String
Dim strNewName As String
Dim withoutextension As String
Dim extension As String
Try
strOldName = strTargetPath & strName
withoutextension = Path.GetFileNameWithoutExtension(strOldName)
extension = Path.GetExtension(strOldName)
strNewName = strDestPath & withoutextension & extension

ftp_request = CType(System.Net.FtpWebRequest.Create(strName), System.Net.FtpWebRequest)
ftp_request.Method = System.Net.WebRequestMethods.Ftp.UploadFile
ftp_request.Credentials = New System.Net.NetworkCredential("user", "user123")
ftp_request.UseBinary = True
ftp_request.KeepAlive = False
ftp_request.Proxy = Nothing
Dim response As FtpWebResponse = DirectCast(ftp_request.GetResponse(), FtpWebResponse)
Dim responseStream As IO.Stream = response.GetResponseStream

Dim fs As New IO.FileStream(strNewName, 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
responseStream.Close()
fs.Flush()
fs.Close()
responseStream.Close()
response.Close()
Catch ex As WebException
Dim response As FtpWebResponse = ex.Response
If response.StatusCode = FtpStatusCode.ActionNotTakenFileUnavailable Then
MsgBox(response.StatusDescription)
Return String.Empty
Else
MsgBox(response.StatusDescription)
End If
End Try
End Function
 

JohnH

VB.NET Forum Moderator
Staff member
Joined
Dec 17, 2005
Messages
15,410
Location
Norway
Programming Experience
10+
Function DownloadImage said:
ftp_request.Method = System.Net.WebRequestMethods.Ftp.UploadFile
That's why.

PS - explore the possibilities you have for making code posted in this forum more readable.
 
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