ASP.NET过滤HTML标签只保留换行与空格的方法

本文实例讲述了ASP.NET过滤HTML标签只保留换行与空格的方法。分享给大家供大家参考。具体分析如下:

自己从网上找了一个过滤HTML标签的方法,我也不知道谁的才是原创的,反正很多都一样。我把那方法复制下来,代码如下:

代码如下:

///   <summary>

///   去除HTML标记

///   </summary>

///   <param name="NoHTML">包括HTML的源码   </param>

///   <returns>已经去除后的文字</returns>

public static string NoHTML(string Htmlstring)

{

  //删除脚本

  Htmlstring = Regex.Replace(Htmlstring, @"<script[^>]*?>.*?</script>", "",

    RegexOptions.IgnoreCase);

  //删除HTML

  Htmlstring = Regex.Replace(Htmlstring, @"<(.[^>]*)>", "",

    RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"([\r\n])[\s]+", "",

    RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"-->", "", RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"<!--.*", "", RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"&(quot|#34);", "\"",

    RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"&(amp|#38);", "&",

    RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"&(lt|#60);", "<",

    RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"&(gt|#62);", ">",

    RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"&(nbsp|#160);", "   ",

    RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"&(iexcl|#161);", "\xa1",

    RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"&(cent|#162);", "\xa2",

    RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"&(pound|#163);", "\xa3",

    RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"&(copy|#169);", "\xa9",

    RegexOptions.IgnoreCase);

  Htmlstring = Regex.Replace(Htmlstring, @"(\d+);", "",

    RegexOptions.IgnoreCase);

  Htmlstring.Replace("<", "");

  Htmlstring.Replace(">", "");

  Htmlstring.Replace("\r\n", "");

  Htmlstring = HttpContext.Current.Server.HtmlEncode(Htmlstring).Trim();

  return Htmlstring;

}

以上代码是从网上直接复制过来的,这个确实能过滤掉所有的HTML标签,但是这个不是我想要的,这个过滤得太干净了,我如果用textarea输入框的话,我是要保留空格跟换行的。

然后我就自己改了一下这个方法,textarea的换行是\n,所以我得把这些标签重新匹配替换成<br>,这样的话从数据库中读取到页面时,就能正确的换行了,把空格替换成HTML的空格符,大功告成。

代码如下:

///   <summary>

///   去除HTML标记(保留br跟\r\n)

///   </summary>

///   <param   name="NoHTML">包括HTML的源码   </param>

///   <returns>已经去除后的文字</returns>

public static string NewNoHTML(string Htmlstring)

{

    //Htmlstring.Replace("\\r\\n", "%r%n").Replace("<br>","%br%").Replace("<br/>","%br&%").Replace("\\n","%n");

    //删除脚本

    Htmlstring = Regex.Replace(Htmlstring, @"<script[^>]*?>.*?</script>", "",

      RegexOptions.IgnoreCase);

    //删除HTML

    Htmlstring = Regex.Replace(Htmlstring, @"<(.[^>]*)>", "",

      RegexOptions.IgnoreCase);

   

    Htmlstring = Regex.Replace(Htmlstring, @"-->", "", RegexOptions.IgnoreCase);

    Htmlstring = Regex.Replace(Htmlstring, @"<!--.*", "", RegexOptions.IgnoreCase);

    Htmlstring = Regex.Replace(Htmlstring, @"&(quot|#34);", "\"",

      RegexOptions.IgnoreCase);

    Htmlstring = Regex.Replace(Htmlstring, @"&(amp|#38);", "&",

      RegexOptions.IgnoreCase);

    Htmlstring = Regex.Replace(Htmlstring, @"&(lt|#60);", "<",

      RegexOptions.IgnoreCase);

    Htmlstring = Regex.Replace(Htmlstring, @"&(gt|#62);", ">",

      RegexOptions.IgnoreCase);

    Htmlstring = Regex.Replace(Htmlstring, @"&(nbsp|#160);", "   ",

      RegexOptions.IgnoreCase);

    Htmlstring = Regex.Replace(Htmlstring, @"&(iexcl|#161);", "\xa1",

      RegexOptions.IgnoreCase);

    Htmlstring = Regex.Replace(Htmlstring, @"&(cent|#162);", "\xa2",

      RegexOptions.IgnoreCase);

    Htmlstring = Regex.Replace(Htmlstring, @"&(pound|#163);", "\xa3",

      RegexOptions.IgnoreCase);

    Htmlstring = Regex.Replace(Htmlstring, @"&(copy|#169);", "\xa9",

      RegexOptions.IgnoreCase);

    Htmlstring = Regex.Replace(Htmlstring, @"(\d+);", "",

      RegexOptions.IgnoreCase);

    Htmlstring.Replace("<", "");

    Htmlstring.Replace(">", "");

    //Htmlstring.Replace("\r\n", "");

    Htmlstring = HttpContext.Current.Server.HtmlEncode(Htmlstring);

    Htmlstring = Regex.Replace(Htmlstring, @"((\r\n))", "<br>");

    Htmlstring = Regex.Replace(Htmlstring, @"(\r|\n)", "<br>");

    Htmlstring = Regex.Replace(Htmlstring, @"(\s)", " ");

    return Htmlstring;

}

这个过滤可以用于让用户输入发布内容时的过滤。

希望本文所述对大家的asp.net程序设计有所帮助。

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