C# 判断一字符串是否为合法数字（正则表达式）

///   <summary>
         ///  判断一个字符串是否为合法整数(不限制长度)
         ///   </summary>
         ///   <param name="s"> 字符串 </param>
         ///   <returns></returns>
         public   static   bool  IsInteger( string  s)
        {
             string  pattern  =   @" ^\d*$ " ;
             return  Regex.IsMatch(s,pattern);
        }
         /**/ ///   <summary>
         ///  判断一个字符串是否为合法数字(0-32整数)
         ///   </summary>
         ///   <param name="s"> 字符串 </param>
         ///   <returns></returns>
         public   static   bool  IsNumber( string  s)
        {
             return  IsNumber(s, 32 , 0 );
        }
         /**/ ///   <summary>
         ///  判断一个字符串是否为合法数字(指定整数位数和小数位数)
         ///   </summary>
         ///   <param name="s"> 字符串 </param>
         ///   <param name="precision"> 整数位数 </param>
         ///   <param name="scale"> 小数位数 </param>
         ///   <returns></returns>
         public   static   bool  IsNumber( string  s, int  precision, int  scale)
        {
             if ((precision  ==   0 ) && (scale  ==   0 ))
            {
                 return   false ;
            }
             string  pattern  =   @" (^\d{1, " + precision + " } " ;
             if (scale > 0 )
            {
                pattern  +=   @" \.\d{0, " + scale + " }$)| " + pattern;
            }
            pattern  +=   " $) " ;
             return  Regex.IsMatch(s,pattern);
        }