これは非常に大まかなアイデアであり、SEPARATE 終了タグ ( など) を必要とする BLOCK 要素では機能しませんが、次のような自己終了要素では正常に機能します
また、タグ ID の中にはスピーチ マークで囲まれているものとそうでないものがあることにも注意しました。
このコードを大まかに編集して、囲まれていない id タグを検出するルーチンをコピー ペーストしましたが、まだ作業が必要で、短縮することもできます。
<script runat="server">
Dim sourcecode As String
Dim bodycode As String
Dim RetVal As String
Protected Sub Page_Load(sender As Object, e As System.EventArgs)
'
LoadHttpStuff()
If Request.Form("Button1") = "Submit" Then
RetVal = MyGetElementById(Request("Text1"))
End If
End Sub
Private Sub LoadHttpStuff()
Dim request As System.Net.HttpWebRequest
Dim response As System.Net.HttpWebResponse
Dim sr As System.IO.StreamReader
Dim finishat As Long
Dim startat As Long
request = System.Net.HttpWebRequest.Create("http://www.google.com/finance?q=NASDAQ:GOOG")
response = request.GetResponse()
sr = New System.IO.StreamReader(response.GetResponseStream())
sourcecode = sr.ReadToEnd()
startat = InStr(sourcecode, "<body>")
finishat = InStr(sourcecode, "</body>") + 7
bodycode = Mid(sourcecode, startat, finishat - startat)
bodycode = LCase(bodycode)
End Sub
Private Function MyGetElementById(Id As String) As String
Dim tagstart As Long
Dim tagend As Long
Dim posx As Long
Dim item As System.Web.UI.HtmlControls.HtmlGenericControl
Dim test As Boolean
Dim letter As Char
Dim text As String
item = Nothing
test = False
text = ""
If Trim(Id) <> "" Then
'-> with SPEECHMARKS
posx = InStr(bodycode, LCase("id=" & Chr(34) & Id & Chr(34)))
If posx > 0 Then
'find start of tag
Do
posx = posx - 1
letter = Mid(bodycode, posx, 1)
If letter = "<" Then
'found tag start
tagstart = posx
Exit Do
End If
Loop Until posx < 1
If tagstart > 0 Then
posx = InStr(bodycode, LCase("id=" & Chr(34) & Id & Chr(34)))
Do
posx = posx + 1
letter = Mid(bodycode, posx, 1)
If letter = ">" Then
tagend = posx + 1
Exit Do
End If
Loop Until posx >= Len(bodycode)
If tagend > 0 Then
text = Mid(bodycode, tagstart, tagend - tagstart)
test = True
End If
End If
Else
posx = InStr(bodycode, LCase("id=" & Id))
If posx > 0 Then
'find start of tag
Do
posx = posx - 1
letter = Mid(bodycode, posx, 1)
If letter = "<" Then
'found tag start
tagstart = posx
Exit Do
End If
Loop Until posx < 1
If tagstart > 0 Then
posx = InStr(bodycode, LCase("id=" & Id))
Do
posx = posx + 1
letter = Mid(bodycode, posx, 1)
If letter = ">" Then
tagend = posx + 1
End If
Loop Until posx >= Len(bodycode)
If tagend > 0 Then
text = Mid(bodycode, tagstart, tagend - tagstart)
test = True
End If
End If
End If
End If
End If
Return Text
End Function
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<table style="width: 100%;">
<tr>
<td style="text-align:left; vertical-align: top; width: 75%;"><textarea rows="20" cols="80" style="width: 90%;" disabled="disabled"><%=sourcecode%></textarea></td>
<td style="width: 25%; text-align: left; vertical-align: top;">
<table style="width:100%;">
<tr>
<td>Element Id <input id="Text1" name="Text1" type="text" /></td>
</tr><tr>
<td> </td>
</tr><tr>
<td> </td>
</tr><tr>
<td><input id="Button1" type="Submit" value="Submit" name="Button1" /></td>
</tr><tr>
<td> </td>
</tr><tr>
<td> </td>
</tr>
</table>
</td>
</tr><tr>
<td style="width: 75%;"> </td>
<td style="width: 25%;"> </td>
</tr><tr>
<td style="width: 100%;" colspan="2"><textarea rows="20" cols="80" style="width: 75%;" disabled="disabled"><%=RetVal%></textarea></td>
<td style="width: 25%;"> </td>
</tr>
</table>
</form>
</body>
</html>
それが少し役立つことを願っています