C#正则表达式匹配字符串

正则表达式可以快速判断所给字符串是否某种指定格式。这里将一些常用的方法封装进一个字符串工具类中。

 public static class StringTool
 {
     /// <summary>
     /// 判断字符串是否纯数字
     /// </summary>
     /// <param name="str"></param>
     /// <returns></returns>
     public static bool IsNumber(string str)
     {
         return Regex.IsMatch(str, @"^[0-9]+$");
     }

     /// <summary>
     /// 判断字符串是否纯字母
     /// </summary>
     /// <param name="str"></param>
     /// <returns></returns>
     public static bool IsLetter(string str)
     {
         return Regex.IsMatch(str, @"^[A-Za-z]+$");
     }

     /// <summary>
     /// 判断字符串是否字母或数字的组合
     /// </summary>
     /// <param name="str"></param>
     /// <returns></returns>
     public static bool IsLetterOrNumber(string str)
     {
         return Regex.IsMatch(str, @"(?i)^[0-9a-z]+$");
     }

     /// <summary>
     /// 统计字符串中汉字个数
     /// </summary>
     /// <param name="str"></param>
     /// <returns></returns>
     public static int CountChinese(string str)
     {
         return str.Count(c => Regex.IsMatch(c.ToString(), @"^[\u4E00-\u9FA5]{0,}$"));
     }

     /// <summary>
     /// 判断字符串是否纯中文
     /// </summary>
     /// <param name="str"></param>
     /// <returns></returns>
     public static bool IsChinese(string str)
     {
         return Regex.IsMatch(str, @"^[\u4e00-\u9fa5],{0,}$");
     }

     /// <summary>
     /// 判断字符串中是否包含中文
     /// </summary>
     /// <param name="str"></param>
     /// <returns></returns>
     public static bool HasChinese(string str)
     {
         return Regex.IsMatch(str, @"[\u4e00-\u9fa5]");
     }

     /// <summary>
     /// 统计字符串中全角字符个数
     /// </summary>
     /// <param name="str"></param>
     /// <returns></returns>
     public static int CountSbcCase(string str)
     {
         return Encoding.Default.GetByteCount(str) - str.Length;
     }

     /// <summary>
     /// 判断字符串中是否包含全角字符
     /// </summary>
     /// <param name="str"></param>
     /// <returns></returns>
     public static bool HasSbcCase(string str)
     {
         return CountSbcCase(str) > ;
     }

     /// <summary>
     /// 统计字符串中半角字符个数
     /// </summary>
     /// <param name="str"></param>
     /// <returns></returns>
     public static int CountDbcCase(string str)
     {
         return str.Length - CountSbcCase(str);
     }

     /// <summary>
     /// 判断字符串中是否包含半角字符
     /// </summary>
     /// <param name="str"></param>
     /// <returns></returns>
     public static bool HasDbcCase(string str)
     {
         return CountDbcCase(str) > ;
     }

     /// <summary>
     /// 判断字符串中是否符合邮箱格式
     /// </summary>
     /// <param name="str"></param>
     /// <returns></returns>
     public static bool IsEmail(string str)
     {
         return Regex.IsMatch(str, @"^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$");
     }
 }