各位老师，我想通过以下代码去获取省市县乡村，但这个代码存在漏洞，比如在执行第2级的时候如果是“市辖区”没有a标签，就行提示错误。所以我想求助老师怎么在这个代码中判定有没有a标签
Dim url As String = "http://www.stats.gov.cn/tjsj/tjbz/tjyqhdmhcxhfdm/2015/"
For i As Integer = 11 To 65
Dim web As new System.Windows.Forms.WebBrowser
web.Navigate(url & i & ".html")
Do While web.ReadyState <> 4
Application.DoEvents
Loop
Dim trs = web.Document.GetElementsByTagName("table")(4).GetElementsByTagName("tr")
For j As Integer = 1 To trs.count - 1
Dim tr = trs(j)
Dim tds = tr.GetElementsByTagName("td")
output.show(tds(0).innerText) '最终显示第2级的ID
output.show(tds(1).innerText) '最终显示第2级的名称
' output.show(tds(1).GetElementsByTagName("a")(0).GetAttribute("href"))
Dim web1 As new System.Windows.Forms.WebBrowser
web1.Navigate(tds(1).GetElementsByTagName("a")(0).GetAttribute("href"))
Do While web1.ReadyState <> 4
Application.DoEvents
Loop
Dim trs1 = web1.Document.GetElementsByTagName("table")(4).GetElementsByTagName("tr")
For j1 As Integer = 1 To trs1.count - 1
Dim tr1 = trs1(j1)
Dim tds1 = tr1.GetElementsByTagName("td")
output.show(tds1(0).innerText) '最终显示第3级的ID
output.show(tds1(1).innerText) '最终显示第3级的名称
'output.show(tds1(1).GetElementsByTagName("a")(0).GetAttribute("href"))
Dim web2 As new System.Windows.Forms.WebBrowser
web2.Navigate(tds1(1).GetElementsByTagName("a")(0).GetAttribute("href"))
Do While web2.ReadyState <> 4
Application.DoEvents
Loop
Dim trs2 = web2.Document.GetElementsByTagName("table")(4).GetElementsByTagName("tr")
For j2 As Integer = 1 To trs2.count - 1
Dim tr2 = trs2(j2)
Dim tds2 = tr2.GetElementsByTagName("td")
output.show(tds2(0).innerText) '最终显示第4级的ID
output.show(tds2(1).innerText) '最终显示第4级的名称
'output.show(tds2(1).GetElementsByTagName("a")(0).GetAttribute("href"))
Dim web3 As new System.Windows.Forms.WebBrowser
web3.Navigate(tds2(1).GetElementsByTagName("a")(0).GetAttribute("href"))
Do While web3.ReadyState <> 4
Application.DoEvents
Loop
' 循环打印di
Dim trs3 = web3.Document.GetElementsByTagName("table")(4).GetElementsByTagName("tr")
For j3 As Integer = 1 To trs3.count - 1
Dim tr3 = trs3(j3)
Dim tds3 = tr3.GetElementsByTagName("td")
output.show(tds3(0).innerText) '显示第5级Id
'output.show(tds3(1).innerText) '显示页面Id
output.show(tds3(2).innerText) '显示5级名称
Next
'web3 = Nothing
web3.Dispose
Return ""
Next
'web2 = Nothing
web2.Dispose
Return ""
Next
'web1 = Nothing
web1.Dispose
Return ""
Next
web.Dispose
Return ""
Next
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Post By：2016/7/20 17:31:00 [只看该作者]
