C#实现简单过滤非法字符实例

#region 过滤非法字符public static string encoding(string src){  if (src == null)   return "";  StringBuilder result = new StringBuilder();  if (src != null)  {   src = src.Trim();   for (int pos = 0; pos < src.Length; pos++)   {    switch (src[pos])    {     case '/"': result.Append("''"); break;     case '<': result.Append("<"); break;     case '>': result.Append(">"); break;     case '/'': result.Append("'"); break;     case '&': result.Append("&"); break;     case '%': result.Append("&pc;"); break;     case '_': result.Append("&ul;"); break;     case '#': result.Append("&shap;"); break;     case '?': result.Append("&ques;"); break;     default: result.Append(src[pos]); break;    }   }  }  return result.ToString();}#endregion