VB.NET 网抓技巧分享(有道翻译为例)

function(e) {
        var t = n.md5(navigator.appVersion)
          , r = "" + (new Date).getTime()
          , i = r + parseInt(10 * Math.random(), 10);
        return {
            ts: r,
            bv: t,
            salt: i,
            sign: n.md5("fanyideskweb" + e + i + "n%A-rKaT5fb[Gy?;N5@Tj")
        }

Imports System.IO
Imports System.Net
Imports System.Text
Imports System.Web

Public Class Form1
    ''翻译网址
    Private Const YDURL As String = "http://fanyi.youdao.com/translate_o?smartresult=dict&smartresult=rule"

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Debug.Print(Get_youdaoxx(GET_STR(TextBox1.Text)))
        Dim res As String = PostData(YDURL, Get_youdaoxx(GET_STR(TextBox1.Text)))
        Dim jstr As String = GET_JSONDATA(res)
        TextBox2.Text = jstr
    End Sub

    ''' <summary>
    ''' 解析翻译结果
    ''' </summary>
    ''' <param name="sttr"></param>
    ''' <returns></returns>
    Public Function GET_JSONDATA(ByVal sttr As String) As String
        Try
            Dim js As Object
            js = CreateObject("ScriptControl")
            js.Language = "JScript"
            js.AddCode("var json=" & sttr & ";var jss = eval(json);var al= jss.translateResult[0].length;var strr='';for (var i=0;i<al;i++){ strr=strr+jss.translateResult[0][i].tgt;}")
            js.State = 1
            js.allowui = True
            Return js.eval("strr")
        Catch ex As Exception
            Return "json数据解析失败"
        End Try

    End Function

    ''' <summary>
    ''' 字符串处理
    ''' </summary>
    ''' <param name="ST"></param>
    ''' <returns></returns>
    Function GET_STR(ByVal ST As String) As String
        On Error Resume Next
        Dim TMP As String = ""
        TMP &= Replace(Replace(Replace(ST, vbCrLf, ""), vbCr, ""), vbLf, "")
        Return TMP

    End Function

    ''' <summary>
    ''' 获取post数据
    ''' </summary>
    ''' <param name="str"></param>
    ''' <returns></returns>
    Function Get_youdaoxx(ByVal str As String) As String
        On Error Resume Next
        Dim MD As New JsMd5
        Dim bv As String = MD.md5("5.0 (Windows)")
        Dim ts As String = GetTimeStamp()
        Dim salt As String = GetTimeStamp() & "1"
        Dim sign As String = MD.md5("fanyideskweb" & str & salt & "n%A-rKaT5fb[Gy?;N5@Tj")
        Dim t_str As String = HttpUtility.UrlEncode(str, Encoding.GetEncoding("utf-8")) '.ToUpper
        Return "i=" & t_str & "&from=" & ComboBox1.Text.ToString.Split("|")(1) & "&to=" & ComboBox2.Text.ToString.Split("|")(1) & "&smartresult=dict&client=fanyideskweb&salt=" & salt & "&sign=" & sign & "&ts=" & ts & "&bv=" & bv & "&doctype=json&version=2.1&keyfrom=fanyi.web&action=FY_BY_REALTlME"
    End Function

    ''' <summary>
    ''' 获取时间截
    ''' </summary>
    ''' <param name="bflag"></param>
    ''' <returns></returns>
    Function GetTimeStamp(Optional bflag = False) As String
        On Error Resume Next
        Dim span As TimeSpan = Date.UtcNow - New DateTime(1970, 1, 1, 0, 0, 0, 0)
        Dim ret As String
        If bflag Then
            ret = Convert.ToInt64(span.TotalSeconds).ToString()
        Else
            ret = Convert.ToInt64(span.TotalMilliseconds).ToString()
        End If
        Return ret
    End Function

    ''' <summary>
    ''' POST请求翻译结果
    ''' </summary>
    ''' <param name="url"></param>
    ''' <param name="data"></param>
    ''' <returns></returns>
    Function PostData(ByVal url As String, ByVal data As String) As String
        On Error Resume Next
        Dim request As HttpWebRequest = WebRequest.Create(url)
        request.Method = "POST"
        request.Host = "fanyi.youdao.com"
        request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:69.0) Gecko/20100101 Firefox/69.0"
        request.Accept = "application/json, text/javascript, */*; q=0.01"
        request.ContentType = "application/x-www-form-urlencoded; charset=UTF-8"
        request.Referer = "http://fanyi.youdao.com/"
        request.Headers.Set("Cookie", "td_cookie=3685168649; YOUDAO_MOBILE_ACCESS_TYPE=1; OUTFOX_SEARCH_USER_ID=66319307@10.169.0.84; OUTFOX_SEARCH_USER_ID_NCOO=189249582.97468826; JSESSIONID=aaauLcGg98nVZ4ETKmQ2w; ___rl__test__cookies=" & GetTimeStamp())
        Dim encoding As New UTF8Encoding()
        Dim bys As Byte() = encoding.GetBytes(data)
        request.ContentLength = bys.Length
        Dim newStream As Stream = request.GetRequestStream()
        newStream.Write(bys, 0, bys.Length)
        newStream.Close()
        Dim sr As StreamReader = New StreamReader(request.GetResponse().GetResponseStream)
        Return sr.ReadToEnd
    End Function

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        MaximizeBox = False
    End Sub


End Class

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