C#判断一个字符串是否为整数

/// <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);