使用正则表达式写的清除Html控制代码的方法。
private static string html2TextPattern =
@"(?<script><script[^>]*?>.*?</script>)|(?<style><style>.*?</style>)|(?<comment><!--.*?-->)" +
@"|(?<html><[^>]+>)" + // HTML标记
@"|(?<quot>&(quot|#34);)" + // 符号: "
@"|(?<amp>&(amp|#38);)" + // 符号: &
@"|(?<lt>&(lt|#60);)" + // 符号: <
@"|(?<gt>&(gt|#62);)" + // 符号: >
@"|(?<iexcl>&(iexcl|#161);)" + // 符号: (char)161
@"|(?<cent>&(cent|#162);)" + // 符号: (char)162
@"|(?<pound>&(pound|#163);)" + // 符号: (char)163
@"|(?<copy>&(copy|#169);)" + // 符号: (char)169
@"|(?<others>&(\d+);)" + // 符号: 其他
@"|(?<space> | )"; // 空格
/// <summary>
/// 转换HTML为纯文本
/// </summary>
/// <param name="html">HTML字符串</param>
/// <param name="keepFormat">是否保留换行格式</param>
/// <returns></returns>
public static string Html2Text(string html, bool keepFormat)
{
string pattern = html2TextPattern;
if (! keepFormat) pattern += "|(?<control>[\r\n\\s])"; // 换行字符
RegexOptions options = RegexOptions.IgnoreCase | RegexOptions.Singleline | RegexOptions.Compiled;
string txt = Regex.Replace(html, pattern, new MatchEvaluator(Html2Text_Match), options);
if (! keepFormat)
return Regex.Replace(txt.Trim(), "[\u0020]+", "\u0020", options); // 替换多个连续空格
else
return txt;
}
private static string Html2Text_Match(Match m)
{
if (m.Groups["quot"].Value != string.Empty)
return "\"";
else if (m.Groups["amp"].Value != string.Empty)
return "&";
else if (m.Groups["lt"].Value != string.Empty)
return "<";
else if (m.Groups["gt"].Value != string.Empty)
return ">";
else if (m.Groups["iexcl"].Value != string.Empty)
return "\xa1";
else if (m.Groups["cent"].Value != string.Empty)
return "\xa2";
else if (m.Groups["pound"].Value != string.Empty)
return "\xa3";
else if (m.Groups["copy"].Value != string.Empty)
return "(c)";
else if (m.Groups["space"].Value != string.Empty)
return "\u0020";
else if (m.Groups["control"].Value != string.Empty)
return "\u0020";
else
return string.Empty;
}