vb2008如何采集一个网页的源码。

[wyj518]

vb2008如何采集一个网页的源码。请教。

[rayyu1989]

''' <summary>
    ''' 下载文档
    ''' </summary>
    ''' <param name="uri">网址</param>
    ''' <param name="encoder">Encoding编码</param>
    ''' <returns>下载的文档，失败为nothing</returns>
    ''' <remarks></remarks>
    Protected Friend Shared Function DownloadString(uri As String, Optional ByVal encoder As Encoding = Nothing) As String
        Dim value As String = Nothing
        If encoder Is Nothing Then
            encoder = Encoding.GetEncoding("utf-8")
        End If
        Dim h As WebClient = Nothing
        Try
            h = New WebClient()
            With h
                .Encoding = encoder
                .Credentials = CredentialCache.DefaultCredentials   '获取或设置用于对向 Internet 资源的请求进行身份验证的网络凭据。
                .Headers.Add("Accept", "image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*")
                .Headers.Add("Accept-Language", "zh-CN")
                .Headers.Add("User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1)")
                value = .DownloadString(uri)
            End With
        Catch ex As ArgumentOutOfRangeException
            value = String.Empty
        Catch ex As ArgumentException
            value = String.Empty
        Catch ex As NotSupportedException
            value = String.Empty
        Catch ex As WebException
            value = String.Empty
        Finally
            If h IsNot Nothing Then
                h.Dispose()
                h = Nothing
            End If
            If value Is Nothing Then
                value = String.Empty
            End If
        End Try
        Return value
    End Function

DownloadString Get请求
UploadString Post请求

[rayyu1989]

修正下注释 ： 下载的文档，失败为String.Empty

[rayyu1989]

嫌代码多 可以把try catch去掉，但是如果页面404 那些就处理不了了

[wyj518]

顶 ，不错就是 代码 太多，有更少的代码吗？

[tk600158]

哥们，给你来个最短的

Dim HTTP as New system.net.WebClient
HTTP.Encoding=System.Text.Encoding.utf8'有些网站可以省略词句
Dim Str as string=HTTP.DownloadString("http://www.163.com")
debug.print(Str)

[threenewbee]

使用 webclient 或者 httpwebrequest 对象。