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：

复制代码 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。

复制代码 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").Replace("<br>","%br%").Replace("<br/>","%br&%").Replace("");

//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。

更多信息请查看IT技术专栏