判断字符串是否为全数字

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace test
{
    class Program
    {
        // 检查字符串是否全为数字

        public bool IsNum(string Str)
        {
            bool blResult = true;
            if (Str == "")
                blResult = false;
            else
            {
                foreach (char Char in Str)
                {
                    if (!Char.IsNumber(Char))
                    {
                        blResult = false;
                        break;
                    }
                }
                if (blResult)
                    if (int.Parse(Str) == 0)
                        blResult = false;
            }
            return blResult;
        }

      static void Main(string[] args)
        {
            Program p = new Program();
            Console.WriteLine("请输入字符串");
            string s = Console.ReadLine();
            if (p.IsNum(s))
            {
                Console.WriteLine("全为数字");
            }
            else
            {
                Console.WriteLine("不是全为数字");
            }
            Console.ReadLine();

        }
    }
}