为什么这无限循环？

Question

所以我今天刚刚把我的网站从服务器上踢了,我觉得这个功能是罪魁祸首.谁能告诉我这是什么问题？我似乎无法弄清楚:

Public Function CleanText(ByVal str As String) As String    
'removes HTML tags and other characters that title tags and descriptions don't like
    If Not String.IsNullOrEmpty(str) Then
        'mini db of extended tags to get rid of
        Dim indexChars() As String = {"<a", "<img", "<input type=""hidden"" name=""tax""", "<input type=""hidden"" name=""handling""", "<span", "<p", "<ul", "<div", "<embed", "<object", "<param"}

        For i As Integer = 0 To indexChars.GetUpperBound(0) 'loop through indexchars array
            Dim indexOfInput As Integer = 0
            Do 'get rid of links
                indexOfInput = str.IndexOf(indexChars(i)) 'find instance of indexChar
                If indexOfInput <> -1 Then
                    Dim indexNextLeftBracket As Integer = str.IndexOf("<", indexOfInput) + 1
                    Dim indexRightBracket As Integer = str.IndexOf(">", indexOfInput) + 1
                    'check to make sure a right bracket hasn't been left off a tag
                    If indexNextLeftBracket > indexRightBracket Then 'normal case
                        str = str.Remove(indexOfInput, indexRightBracket - indexOfInput)
                    Else
                        'add the right bracket right before the next left bracket, just remove everything
                        'in the bad tag
                        str = str.Insert(indexNextLeftBracket - 1, ">")
                        indexRightBracket = str.IndexOf(">", indexOfInput) + 1
                        str = str.Remove(indexOfInput, indexRightBracket - indexOfInput)
                    End If
                End If
            Loop Until indexOfInput = -1
        Next
    End If
    Return str
End Function

Answer 1

这样的事情会不会更简单？(好的,我知道它与发布的代码不一样):

public string StripHTMLTags(string text)
{
    return Regex.Replace(text, @"<(.|\n)*?>", string.Empty);
}

(转换为VB.NET应该是微不足道的!)

注意:如果您经常运行此功能,则可以对该功能进行两项性能改进Regex.

一种是使用预编译的表达式,这需要稍微重写.

第二种是使用正则表达式的非捕获形式; .NET正则表达式实现了(？:)语法,允许进行分组而不会导致被捕获文本的性能损失被记住为反向引用.使用此语法,上面的正则表达式可以更改为:

@"<(?:.|\n)*?>"