这里分享两个做爬虫的函数，一个用来拿到cookie，另一个用cookie拿到网页内容。
1.登录后需要记下网站的cookie，这是个获得cookie的小工具。使用它的前提是你已经完成登录过程，比如用WebBrowser控件完成了用户名、密码的登录（参考这里）。参数中url是可以登录的页面地址，errmsg是目标网站可能返回的出错信息，比如“错误”“未登录”之类。返回值是cookie字符串。
Private Declare Function InternetGetCookieEx Lib "wininet.dll" Alias "InternetGetCookieExA" (ByVal url As String, ByVal cookieName As String, ByVal cookieData As String, ByRef size As Long, ByVal flags As Long, ByVal pReserved As Long) As Boolean
Private Const INTERNET_COOKIE_HTTPONLY As Integer = 8192
Function getCookie(url As String, errmsg As String) As String
Dim cookietmp As String * 8192
Dim dummy As Variant
Dim pcchCookiedata As Long
pcchCookiedata = 8192
Dim HTTP As Object
On Error GoTo errhandler
Set HTTP = CreateObject("msxml2.xmlhttp.6.0")
HTTP.Open "get", url, False
HTTP.send
If InStr(1, HTTP.responsetext, errmsg) <> 0 Or HTTP.responsetext = "" Then
getCookie = ""
Else
If Not InternetGetCookieEx(url, vbNullString, cookietmp, pcchCookiedata, INTERNET_COOKIE_HTTPONLY, 0) Then
dummy = InternetGetCookieEx(url, vbNullString, vbNullString, pcchCookiedata, INTERNET_COOKIE_HTTPONLY, 0)
End If
getCookie = Mid(cookietmp, 1, pcchCookiedata - 1)
End If
Set HTTP = Nothing
Exit Function
errhandler:
getCookie = ""
Exit Function
End Function
2.拿到cookie后，就可以用它访问需要登录的网页，用这个函数拿到网页的响应。其中errmsg是目标网页可能给出的出错信息，nRetry是出错后你能接受的最大重试次数。注意，xmlhttp是不支持cookie的，必须用serverxmlhttp。
Function httpRequest(url, cookie, errmsg, nRetry)
Dim HTTP
On Error Resume Next
For j = 0 To nRetry - 1
Set HTTP = Nothing
Set HTTP = CreateObject("msxml2.serverxmlhttp.6.0")
Err.Clear
HTTP.setTimeouts 0, 5000, 5000, 15000
HTTP.Open "get", url, True
HTTP.setRequestHeader "Cookie", cookie
HTTP.setRequestHeader "Connection", "keep-alive"
HTTP.send
If HTTP.waitForResponse(15) = False Then
HTTP.abort
temp = ""
Else
temp = HTTP.responsetext
End If
errFlag = Err.Description <> "" Or Len(temp) = 0 Or InStr(1, temp, errmsg) <> 0
If errFlag = False Then
Set HTTP = Nothing
httpRequest = temp
nRetry = j
Exit Function
End If
Next 'j
Set HTTP = Nothing
httpRequest = temp
End Function
以上。
爬的老狼
感谢分享! 非常棒!
咋不行呢，返回未登录！
咋不行呢，返回未登录！