6.20 类库（隐藏代码类库+非隐藏代码借用）

隐藏代码类库

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

namespace 隐藏代码的类库
{
    public class chufa
    {
        /// <summary>
        /// 除法
        /// </summary>
        /// <param name="a">第一个数</param>
        /// <param name="b">第二个数</param>
        /// <returns></returns>
        public double chu(int a, int b)
        {
            return Convert.ToDouble(a / b);
        }
    }
}

非隐藏代码借用

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using 算数;
using 隐藏代码的类库;

namespace 类库
{
    class Program
    {
        static void Main(string[] args)
        {
            //非隐藏代码的类库
            var a = 10;
            var b = 20;

            suanshu g = new suanshu();
            var d = g.jiafa(a, b);
            var e = g.jianfa(a, b);
            Console.WriteLine(d);
            Console.WriteLine(e);
            Console.WriteLine(d + "   " + e);
            //隐藏代码的类库
            chengfa cf = new chengfa();
            var h = cf.cheng(a, b);
            Console.WriteLine(h);


            chufa gf = new chufa();
            var j = gf.chu(a, b);
            Console.WriteLine(j);//
            Console.WriteLine(Convert.ToDecimal(a * 1.0 / b));//为什么用这种写法？？？
           //默认是double 类型   在类库里面修改算法  返回值

          

            Console.ReadLine();





        }

    }
}

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


namespace 算数
{
    class suanshu
    {
        /// <summary>
        /// 加法运算
        /// </summary>
        /// <param name="a">参数a</param>
        /// <param name="b">参数b</param>
        /// <returns></returns>
        public int  jiafa(int a, int b)
        {
            return a + b;
        }
        /// <summary>
        /// 减法运算
        /// </summary>
        /// <param name="a">参数a</param>
        /// <param name="b">参数b</param>
        /// <returns></returns>
        public int jianfa (int a,int b)
        {
            return a - b;
    }


    }
}