马牛的C#学习（第三天）

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函数的重载：

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

namespace ConsoleApplication1
{
    class Program
    {
        static void TryFunc(double x)
        {
            Console.WriteLine("this is double/n");
        }
        static void TryFunc(int y)
        {
            Console.WriteLine("this is int");
        }

        static void Main(string[] args)
        {
            TryFunc(2.5);
            TryFunc(9);
        }
    }
}

C#根据输入的类型智能地选择函数。

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使用委托：

using System;
using System.Collections.Generic;
using System.Text;
//委托就是使一个委托等于一个函数，便可像使用函数一样使用这个委托。如果需要，还可以令这个委托委托另一个函数，实现另一个功能！
namespace ConsoleApplication1
{
    class Program
    {

        delegate void showDelegage(int i);

        static void ShowBig(int p)
        {
            Console.WriteLine("this is show Big :::{0}:::/n", p);
        }
        static void ShowSmall(int p)
        {
            Console.WriteLine("this is show small :::{0}:::/n", p);
        }

        static void Main(string[] args)
        {
            showDelegage ShowNum;
            int input = Convert.ToInt32( Console.ReadLine() );  //C#中数值的一种输入方式

            //如果INPUT大于1000，就把SHOWBIG委托给SHOWNUM，否则把SHOWSMALL委托给SHOWNUM
            if (input > 1000) ShowNum = new showDelegage(ShowBig);
            else ShowNum = new showDelegage(ShowSmall);
            Console.WriteLine("just input = {0}/n", input);
            ShowNum(input);
        }
    }
}

 

委托：

using System;
using System.Collections.Generic;
using System.Text;
//用委托SHOWNUM模拟CONSOLE.READLINE()函数
namespace ConsoleApplication1
{
    class Program
    {

        delegate string showDelegage();

        static void Main(string[] args)
        {
            showDelegage ShowNum;
            ShowNum = new showDelegage(Console.ReadLine);
            string input = ShowNum();
            Console.WriteLine("this is input {0}/n", input);
        }
    }
}

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using System;
using System.Collections.Generic;
using System.Text;
//结构函数，在结构体中定义的函数，方便对结构体的操作，亦便于理解
//本程序在结构体中定义printorder来打印菜单
namespace ConsoleApplication1
{
    class Program
    {

        struct order
        {
            public string itemName;
            public int unitCount;
            public double unitCost;
            public void printorder()             //CARE！这里应该用PUBLIC,用STATIC会出错！
            {
                Console.WriteLine("::::::::::::ORDER::::::::::::::/n");
                Console.WriteLine("itemName ==={0}===/nunitCount {1}/nunitCost {2}/n", itemName, unitCount, unitCost);
            }
        }
       

        static void Main(string[] args)
        {
           order orderOfManio;
            orderOfManio.itemName = "OrderOfManio";
            orderOfManio.unitCost = 889;
            orderOfManio.unitCount = 778;
            orderOfManio.printorder();
        }
    }
}

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