Error while downloading a zip file from a website

I am trying to d开发者_运维百科ownload a zip file from a website by using a web client but the file is not getting downloaded properly.

Every time the zip file is getting downloaded with no contents in it,in the destination directory.

Below I paste the code I am using :

Imports System.Net
Imports System.IO
Imports System.Collections.Generic
Imports System.Text
Imports System.Net.NetworkInformation
Imports System.Diagnostics


 Public Class Form1
Private Sub _DownloadProgressChanged(ByVal sender As Object, ByVal e As DownloadProgressChangedEventArgs)
    ' Update progress bar
    ProgressBar1.Value = e.ProgressPercentage
End Sub

Private Sub _DownloadFileCompleted(ByVal sender As Object, ByVal e As System.ComponentModel.AsyncCompletedEventArgs)
    ' File download completed
    Button1.Enabled = Enabled
    MessageBox.Show("Download completed")
End Sub


Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Button1.Enabled = False
    Dim ProcessingDate As Date = DateTime.Now
    Dim File2Download As String = "File Name To Be Downloaded.zip"
    Dim Url As String = "SourceURL" & File2Download 'http site
    Dim _WebClient As New System.Net.WebClient
    _WebClient.UseDefaultCredentials = True
    _WebClient.Headers("User-Agent") = "Mozilla/5.0 (compatible; MSIE 9.0; windows NT 6.1; WOW64; Trident/5.0)"
    _WebClient.Headers("Method") = "GET"
    _WebClient.Headers("AllowAutoRedirect") = True
    _WebClient.Headers("KeepAlive") = True
    _WebClient.Headers("Accept") = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"
    AddHandler _WebClient.DownloadFileCompleted, AddressOf _DownloadFileCompleted
    AddHandler _WebClient.DownloadProgressChanged, AddressOf _DownloadProgressChanged
    _WebClient.DownloadFileAsync(New Uri(Url), "Destination Directory\" & File2Download)
End Sub
End Class

Any help in this regard is earnestly solicited.

Your _WebClient.Headers("Accept") = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8" implies that you are only prepared to accept html or xml documents... you might want to change that to accept zip files "application/zip, application/octet-stream"