利用webbrowser控件，如何破解内容不让复制的限制？

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        WebBrowser1.Navigate("http://www.360doc.com/content/12/1229/11/9200790_256942445.shtml")

    End Sub



    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        WebBrowser1.ScriptErrorsSuppressed = True

        Dim doc As mshtml.IHTMLDocument2 = TryCast(WebBrowser1.Document.DomDocument, mshtml.IHTMLDocument2)

        doc.parentWindow.execScript("document.oncontextmenu=new Function('event.returnValue=true;')", "javascript") '解除右键菜单限制

        doc.parentWindow.execScript("document.onselectstart=new Function('event.returnValue=true;')", "javascript") '解除全选限制

        doc.parentWindow.execScript("document.oncopy=new Function('event.returnValue=true;')", "javascript")

        doc.parentWindow.execScript("document.onselect=new Function('event.returnValue=true;')", "javascript")

        doc.parentWindow.execScript("document.onbeforecopy=new Function('event.returnValue=true;')", "javascript")

        doc.parentWindow.execScript("document.onkeydown=Function('event.returnValue=true;')", "javascript") 'Ctrl+C可用

        Dim elemlist As mshtml.IHTMLElementCollection = doc.getElementsByTagName("script")

        '遍历JS操作

        For Each elem As mshtml.IHTMLElement In elemlist

            If elem.getAttribute("src") IsNot Nothing Then

                elem.setAttribute("src", "#") '禁止js文件

            End If

            If elem.getAttribute("type") IsNot Nothing Then

                elem.setAttribute("type", "text/vbscript") '修改脚本默认语言

            End If

            If elem.getAttribute("language") IsNot Nothing Then

                elem.setAttribute("language", "vbscript") '修改脚本默认语言

            End If

            elem.outerHTML = "<script>return false;</script>" '修改js内容

        Next

        WebBrowser1.Document.Body.InnerHtml = Replace(WebBrowser1.Document.Body.InnerHtml, "document.write", "document..write", 1, -1, vbTextCompare) '禁止写入

        WebBrowser1.Document.Body.InnerHtml = Replace(WebBrowser1.Document.Body.InnerHtml, "iframe", "iiframe", 1, -1, vbTextCompare) '禁止框架

        '以上代码都不起作用

        WebBrowser1.DocumentText = "<html><body>" & WebBrowser1.Document.Body.InnerHtml & "</body></html>" '该行起作用，但把页面破坏的面目全非

    End Sub