在vb.net中使用webbrowser控件和mshtml以及流操作体会(vb.net内嵌IE,拆取 Web 页)(原创)

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!