我的程序一直在使用：
Dim DLLink1 As String
DLLink1 = Trim(TextBox2.Text)
Dim DownloadDirectory1 As String
DownloadDirectory1 = Trim(TextBox4.Text)
Try
Button3.Enabled = False
' My.Computer.Network.DownloadFile(DLLink1, (DownloadDirectory1 + "/UpdatedClient.zip"))
Dim HttpReq As HttpWebRequest = DirectCast(WebRequest.Create(DLLink1), HttpWebRequest)
Using HttpResponse As HttpWebResponse = DirectCast(HttpReq.GetResponse(), HttpWebResponse)
Using Reader As New BinaryReader(HttpResponse.GetResponseStream())
Dim RdByte As Byte() = Reader.ReadBytes(1 * 1024 * 1024 * 10)
Using FStream As New FileStream(DownloadDirectory1 + "/UpdatedClient.zip", FileMode.Create)
FStream.Write(RdByte, 0, RdByte.Length)
End Using
End Using
End Using
Finally
MsgBox("Finished Download.")
Button3.Enabled = True
Label4.Visible = True
我以前试过这个，但它根本不起作用：
My.Computer.Network.DownloadFile(DLLink1, (DownloadDirectory1 + "/UpdatedClient.zip"))
该网站要求您登录，因此我为该程序创建了一个备用帐户：
WebBrowser1.Navigate("http://www.mpgh.net/forum/admincp/")
Timer1.Start()
Button2.Enabled = False
然后
WebBrowser1.Document.GetElementById("vb_login_username").SetAttribute("value", "AutoUpdaterAccount")
WebBrowser1.Document.GetElementById("vb_login_password").SetAttribute("value", "password")
Dim allelements As HtmlElementCollection = WebBrowser1.Document.All
For Each webpageelement As HtmlElement In allelements
If webpageelement.GetAttribute("type") = "submit" Then
webpageelement.InvokeMember("click")
Timer1.Stop()
Label5.Text = "Authorized."
Button2.Enabled = True
所以现在你已经登录了网站上的帐户，但是当上面的代码运行时，它会下载一个zip，但它已经损坏了。所以我用notepad++打开它，这就是我得到的（这是否意味着它没有登录下载，它只用webbrowser登录，它们没有链接？或者什么？喜欢我的Firefox登录没有与chrome链接？：
代码很大，就像HTML编码一样。这是我在网上记事本的链接： http://shrib.com/nCOucdfL
另外一件事，一个webbrowser无法在节目上显示，它可以在外面不显示，就像我登录时那样。当弹出一个窗口时，他们也无法像在普通网页浏览器上那样点击保存按钮，我希望它使用一个按钮将目录设置为DownloadDirectory1
答案 0 :(得分：0)
这一定是你的幸运日，因为今天我醒来后决定愿意帮助你解决你的事业。我首先尝试使用Web浏览器控件进行下载，但不幸的是，我确信如果不扩展Web浏览器控件并且我们今天不想这样做，这是不可能的。
正如我在评论中提到的，我真正知道这是可能的（没有用户交互）的唯一方法是通过HttpWebRequest方法登录。这是非常棘手的事情。绝对不适合初学者。
现在我必须承认，这不是最干净，最“适当”和用户友好的代码，所以如果有人想建议一个更好的方法来做事，我很满意。
我建议您先将其测试，然后再将其合并到现有应用中。只需创建一个新的vb.net应用程序，并使用下面的代码替换Form1中的所有代码。您必须使用真实的用户名和密码更新usernamehere和passwordhere字符串。此外，默认情况下文件保存为C:\file.rar，因此您可以根据需要更改此路径。此代码完全消除了对Web浏览器控件的需要（除非您将其用于其他内容），因此一旦您正确合并它，您很可能会将其从实际应用程序中删除：
Imports System.Net
Imports System.IO
Imports System.Text
Public Class Form1
Private Const gsUserAgent As String = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:35.0) Gecko/20100101 Firefox/35.0"
Const sUsername As String = "usernamehere"
Const sPassword As String = "passwordhere"
Const sMainURL As String = "http://www.mpgh.net/"
Const sCheckLoginURL As String = "http://www.mpgh.net/forum/login.php?do=login"
Const sDownloadURL As String = "http://www.mpgh.net/forum/attachment.php?attachmentid=266579&d=1417312178"
Const sCookieLoggedInMessage As String = "mpgh_imloggedin=yes"
Dim oCookieCollection As CookieCollection = Nothing
Dim sSaveFile As String = "c:\file.rar"
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
StartScrape()
End Sub
Private Sub StartScrape()
Try
Dim bContinue As Boolean = True
Dim sPostData(15) As String
sPostData(0) = UrlEncode("vb_login_username")
sPostData(1) = UrlEncode(sUsername)
sPostData(2) = UrlEncode("vb_login_password")
sPostData(3) = UrlEncode(sPassword)
sPostData(4) = UrlEncode("vb_login_password_hint")
sPostData(5) = UrlEncode("Password")
sPostData(6) = UrlEncode("s")
sPostData(7) = UrlEncode("")
sPostData(8) = UrlEncode("securitytoken")
sPostData(9) = UrlEncode("guest")
sPostData(10) = UrlEncode("do")
sPostData(11) = UrlEncode("login")
sPostData(12) = UrlEncode("vb_login_md5password")
sPostData(13) = UrlEncode("")
sPostData(14) = UrlEncode("vb_login_md5password_utf")
sPostData(15) = UrlEncode("")
If GetMethod(sMainURL) = True Then
If SetMethod(sCheckLoginURL, sPostData, sMainURL) = True Then
' Login successful
If DownloadMethod(sDownloadURL, sMainURL) = True Then
MessageBox.Show("File downloaded successfully")
Else
MessageBox.Show("Error downloading file")
End If
End If
End If
Catch ex As Exception
MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
End Sub
Private Function GetMethod(ByVal sPage As String) As Boolean
Dim req As HttpWebRequest
Dim resp As HttpWebResponse
Dim stw As StreamReader
Dim bReturn As Boolean = True
Try
req = HttpWebRequest.Create(sPage)
req.Method = "GET"
req.AllowAutoRedirect = False
req.UserAgent = gsUserAgent
req.Accept = "text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5"
req.Headers.Add("Accept-Language", "en-us,en;q=0.5")
req.Headers.Add("Accept-Charset", "ISO-8859-1,utf-8;q=0.7,*;q=0.7")
req.Headers.Add("Keep-Alive", "300")
req.KeepAlive = True
resp = req.GetResponse ' Get the response from the server
If req.HaveResponse Then
' Save the cookie info if applicable
SaveCookies(resp.Headers("Set-Cookie"))
resp = req.GetResponse ' Get the response from the server
stw = New StreamReader(resp.GetResponseStream)
stw.ReadToEnd() ' Read the response from the server, but we do not save it
Else
MessageBox.Show("No response received from host " & sPage, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
bReturn = False
End If
Catch exc As WebException
MessageBox.Show("Network Error: " & exc.Message.ToString & " Status Code: " & exc.Status.ToString & " from " & sPage, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
bReturn = False
End Try
Return bReturn
End Function
Private Function SetMethod(ByVal sPage As String, ByVal sPostData() As String, sReferer As String) As Boolean
Dim bReturn As Boolean = False
Dim req As HttpWebRequest
Dim resp As HttpWebResponse
Dim str As StreamWriter
Dim sPostDataValue As String = ""
Try
req = HttpWebRequest.Create(sPage)
req.Method = "POST"
req.UserAgent = gsUserAgent
req.Accept = "application/x-shockwave-flash,text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5"
req.Headers.Add("Accept-Language", "en-us,en;q=0.5")
req.Headers.Add("Accept-Charset", "ISO-8859-1,utf-8;q=0.7,*;q=0.7")
req.Referer = sReferer
req.ContentType = "application/x-www-form-urlencoded"
req.Headers.Add("Pragma", "no-cache")
req.Headers.Add("Keep-Alive", "300")
If oCookieCollection IsNot Nothing Then
' Pass cookie info from the login page
req.CookieContainer = SetCookieContainer(sPage)
End If
str = New StreamWriter(req.GetRequestStream)
If sPostData.Count Mod 2 = 0 Then
' There is an even number of post names and values
For i As Int32 = 0 To sPostData.Count - 1 Step 2
' Put the post data together into one string
sPostDataValue &= sPostData(i) & "=" & sPostData(i + 1) & "&"
Next i
sPostDataValue = sPostDataValue.Substring(0, sPostDataValue.Length - 1) ' This will remove the extra "&" at the end that was added from the for loop above
' Post the data to the server
str.Write(sPostDataValue)
str.Close()
' Get the response
resp = req.GetResponse
If req.HaveResponse Then
If resp.Headers("Set-Cookie").IndexOf(sCookieLoggedInMessage) > -1 Then
' Save the cookie info
SaveCookies(resp.Headers("Set-Cookie"))
bReturn = True
Else
MessageBox.Show("The email or password you entered are incorrect." & vbCrLf & vbCrLf & "Please try again.", "Unable to log in", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
bReturn = False
End If
Else
' This should probably never happen.. but if it does, we give a message
MessageBox.Show("The email or password you entered are incorrect." & vbCrLf & vbCrLf & "Please try again.", "Unable to log in", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
bReturn = False
End If
Else
' Did not specify the correct amount of parameters so we cannot continue
MessageBox.Show("POST error. Did not supply the correct amount of post data for " & sPage, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
bReturn = False
End If
Catch ex As Exception
MessageBox.Show("POST error. " & ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
bReturn = False
End Try
Return bReturn
End Function
Private Function DownloadMethod(ByVal sPage As String, sReferer As String) As Boolean
Dim req As HttpWebRequest
Dim bReturn As Boolean = False
Try
req = HttpWebRequest.Create(sPage)
req.Method = "GET"
req.AllowAutoRedirect = False
req.UserAgent = gsUserAgent
req.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"
req.Headers.Add("Accept-Language", "en-US,en;q=0.5")
req.Headers.Add("Accept-Encoding", "gzip, deflate")
req.Headers.Add("Keep-Alive", "300")
req.KeepAlive = True
If oCookieCollection IsNot Nothing Then
' Set cookie info so that we continue to be logged in
req.CookieContainer = SetCookieContainer(sPage)
End If
' Save file to disk
Using oResponse As System.Net.WebResponse = CType(req.GetResponse, System.Net.WebResponse)
Using responseStream As IO.Stream = oResponse.GetResponseStream
Using fs As New IO.FileStream(sSaveFile, FileMode.Create, FileAccess.Write)
Dim buffer(2047) As Byte
Dim read As Integer
Do
read = responseStream.Read(buffer, 0, buffer.Length)
fs.Write(buffer, 0, read)
Loop Until read = 0
responseStream.Close()
fs.Flush()
fs.Close()
End Using
responseStream.Close()
End Using
oResponse.Close()
End Using
bReturn = True
Catch exc As WebException
MessageBox.Show("Network Error: " & exc.Message.ToString & " Status Code: " & exc.Status.ToString & " from " & sPage, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
bReturn = False
End Try
Return bReturn
End Function
Private Function SetCookieContainer(sPage As String) As System.Net.CookieContainer
Dim oCookieContainerObject As New System.Net.CookieContainer
Dim oCookie As System.Net.Cookie
For c As Int32 = 0 To oCookieCollection.Count - 1
If IsDate(oCookieCollection(c).Value) = True Then
' Fix dates as they seem to cause errors/problems
oCookieCollection(c).Value = Format(CDate(oCookieCollection(c).Value), "dd-MMM-yyyy hh:mm:ss")
End If
oCookie = New System.Net.Cookie
oCookie.Name = oCookieCollection(c).Name
oCookie.Value = oCookieCollection(c).Value
oCookie.Domain = New Uri(sPage).Host
oCookie.Secure = False
oCookieContainerObject.Add(oCookie)
Next
Return oCookieContainerObject
End Function
Private Sub SaveCookies(sCookieString As String)
Dim sCookieStrings() As String = sCookieString.Trim.Replace(" HttpOnly,", "").Replace(" HttpOnly", "").Replace(" domain=.mpgh.net,", "").Split(";".ToCharArray())
oCookieCollection = New CookieCollection
For Each sCookie As String In sCookieStrings
If sCookie.Trim <> "" Then
Dim sName As String = sCookie.Trim().Split("=".ToCharArray())(0)
Dim sValue As String = sCookie.Trim().Split("=".ToCharArray())(1)
oCookieCollection.Add(New Cookie(sName, sValue))
End If
Next
End Sub
Private Function UrlEncode(ByRef URLText As String) As String
Dim AscCode As Integer
Dim EncText As String = ""
Dim bStr() As Byte = Encoding.ASCII.GetBytes(URLText)
Try
For i As Long = 0 To UBound(bStr)
AscCode = bStr(i)
Select Case AscCode
Case 48 To 57, 65 To 90, 97 To 122, 46, 95
EncText = EncText & Chr(AscCode)
Case 32
EncText = EncText & "+"
Case Else
If AscCode < 16 Then
EncText = EncText & "%0" & Hex(AscCode)
Else
EncText = EncText & "%" & Hex(AscCode)
End If
End Select
Next i
Erase bStr
Catch ex As WebException
MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
Return EncText
End Function
End Class