需求为:到某一网站抓取查询结果.环境为vb.net
从0开始,一开始具体需要用到.net里的具体什么东东都不清楚,于是就一顿瞎搜索.又是google,又是baidu,yisou......胡乱搜的内容有.net ie,拆分网页 .net,内嵌ie等等.没过多久能得知webbrowser这个控件.
其中对我有帮助比较大的文章是http://www.microsoft.com/china/msdn/Archives/workshop/scrape.ASP
只是这里介绍的vb环境.到.net也没什么太大差别,别笑!我最开始找shdocvw.dll 和 msHTML.dll添加引用时候都费了半天劲.因为大家都说webbrowser.而.net里写的是microsoft web 浏览器..
先按照上面的文章练一练!
不说废话了.
先做一个输入框,和一个按钮,供输入信息,和提交信息.
在按纽的click事件中写:
Dim postdata As String() = {"searchText=" + Me.searchText.Text}
Dim strUrl As String = "http://"
Dim SessionHTML As String = PostDate(strUrl, postdata)
'产生临时文件
Dim sw As StreamWriter = New StreamWriter("D:\1.htm", False, Encoding.GetEncoding("GB2312"))
sw.WriteLine(SessionHTML)
sw.Close()
Me.AxWebBrowserFill.Navigate("D:\1.htm")
PostDate函数如下:
Public Function PostDate(ByVal url As String, ByVal PostData() As String) As String
Dim Post As String = ""
'拼接成传递变量
For Each s As String In PostData
Post += s + "&"
Next
Post = Post.Substring(0, Post.Length - 1)
Dim HTML As String = ""
Dim encoding As Encoding = encoding.GetEncoding("GB2312")
Dim data As Byte() = encoding.GetBytes(Post)
Dim myRequest As HttpWebRequest = CType(WebRequest.Create(url), HttpWebRequest)
myRequest.Method = "post"
myRequest.ContentType = "application/x-www-form-urlencoded"
'myRequest.ContentType = "text/ASP"
myRequest.ContentLength = data.Length
Dim newStream As Stream = myRequest.GetRequestStream()
newStream.Write(data, 0, data.Length)
newStream.Close()
Dim resp As HttpWebResponse = CType(myRequest.GetResponse(), HttpWebResponse)
Dim sr As StreamReader = New StreamReader(resp.GetResponseStream(), System.Text.Encoding.GetEncoding("GB2312"))
'返回HTML代码的字符串
HTML = sr.ReadToEnd()
sr.Close()
Return HTML
End Function
这样就可以了.
至于直接把HTML显示在webbrowser控件中,而不通过临时文件,在网上搜到的都是delphi办法.而.net似乎没有完美的解决办法.
曾经试过:
'AxWebBrowserFill.Navigate(SessionHTML)
'Me.AxWebBrowserFill.Document.write(SessionHTML + "haga")
'Me.axScriptLet.url = "about:blank" + SessionHTML
'Me.AxWebBrowserFill.Document.write(SessionHTML)
'doc = Me.AxWebBrowserFill.Document
'doc.body.innerHTML = SessionHTML
'doc.write(SessionHTML)
往往只是第一次成功,而且中间会涉及到HTML内双引号的问题.
也有网上说按如下方法:
''在WebBrowser中显示报告内容字段
'Dim doc As IHTMLDocument2 = CType(AxWebBrowserFill.Document, IHTMLDocument2)
'Dim bodyElement As IHTMLElement = CType(doc.body, IHTMLElement)
''bodyElement.innerHTML = SessionHTML + "haga"
而这个方法我就没有奏效过!