面向对象
简写重载的方法:重载中如果逻辑重复的情况下,用参数少的调用参数多
参数空缺,可以用null填补
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace m1w3d3_attribute_inherit_visit
{
#region 属性
class Student
{
public Student(string name, int age, char sex)
{
this.name = name;
this.age = age;
this.sex = sex;
}
string name;//可以读,不能写
int age;//年龄不能小于10,不能大于150
char sex;
//1、和方法大体一样,返回类型不能是void,没有参数列表
//如果你保护哪个字段,建议属性名用字段的帕斯卡命名法
//2、属性块中由两个块组成get,set
//get块在被使用(取值)时是被调用
//set块在赋值时才会被调用
//set get块可以由空语句替代
//必须全部由空语句替代,或者没有set
//get块和set块可以只有一个
//3、get块必须有返回值,值类型与属性返回类型一致
//4、在对应字段写入相应逻辑
public string Name
{
get { return " "; }//读
//set { }//写
}
public int Age
{
get { return age; }
set
{
//1、外部传入的值,在set块中用value表示
//age = value;
//if (age < 0) age = 0;
//else if (age > 150) age = 150;
if (value < ) value = ;
else if (value > ) value = ;
age = value;
}
}
}
#endregion
#region 属性的练习1
class Student1
{
public Student1(string name, char sex, int age, float cSharp, float unity)
{
this.name = name;
this.sex = sex;
this.age = age;
this.cSharp = cSharp;
this.unity = unity;
}
//public string name;
//public char sex;
//public int age;
//public float cSharp;
//public float unity;
string name;
char sex;
int age;
float cSharp;
float unity;
public void SayHello()
{
Console.WriteLine("我叫{0},今年{1}岁了,是{2}生,我的CSharp成绩{3},我的Unity成绩{4}", Name, Age, Sex, CSharp, Unity);
}
//public void SaySorce(float cSharp, float unity)
//{
// Console.WriteLine("我的CSharp成绩{0},我的Unity成绩{1}", unity, cSharp);
// Console.WriteLine("我的总分是{0},我的平均分是{1}", (unity + cSharp), (unity + cSharp) / 2);
//}
public string Name
{
get { return name; }
set { }
}
public int Age
{
get
{
if (age < ) age = ;
else if (age > ) age = ;
return age;
}
set
{
age = value;
}
}
public float CSharp
{
get
{
if (cSharp <= ) cSharp = ;
else if (cSharp >= ) cSharp = ;
return cSharp;
}
set
{
cSharp = value;
}
}
public float Unity
{
get
{
return unity;
}
set
{
unity = value;
if (unity <= ) unity = ;
else if (unity >= ) unity = ; }
}
public char Sex
{
get
{
if (sex == '男' || sex == '女')
{
}
else
{
sex = '错';
}
return sex;
}
set
{ sex = value;
}
}
}
#endregion
#region 属性的练习2
class Ticket
{
float price;//写在这里,节约CPU运算
float distance;
public Ticket() { }
public Ticket(float distance)
{
//float price;//写在这里,节约内存空间
if (distance < ) distance = ;
this.distance = distance;
if (distance <= ) price = distance;
else if (distance <= ) price = distance * 0.95f;
else if (distance <= ) price = distance * 0.9f;
else price = distance * 0.8f;
}
public float Price
{
get { return price; }
set { }
}
public float Distance
{
get { return distance; }
}
//在C#中,我们可以通过重写ToString(),去修改一个对象的打印信息
//ToString()必须要返回一个字符串
//Console.WriteLine()默认是用了 格式化字符串
//我们可以通过调用 格式化字符串方法
//String.Format();
public override string ToString()
{
return String.Format("这张票的票价是{0},距离{1}", Price, Distance);
}
}
#endregion
#region 属性的简写
//get set块 可以是空语句,set块可以没有
//这样的属性我们叫做自动属性,自动属性可以帮助我们快速实现一个自动属性
//自动属性有保护的字段
class Student2
{
//public string name;//隐藏字段
public char sex;
public int age;
public float cSharp;
public float unity;
public string Name
{
get;//隐藏字段
set;
}
//public string Name => name;//只读属性的另一种写法
public void SayHello()
{
Console.WriteLine("我叫{0},今年{1}岁了,是{2}生,我的CSharp成绩{3},我的Unity成绩{4}", Name, age, sex, cSharp, unity);
}
}
#endregion
#region 静态类
static class Manager
{
public static int money;
public static Random roll = new Random();
}
class Fighter
{
string name;
public Fighter(string name)
{
this.name = name;
}
int health;
public void FindMoney()
{
int num = Manager.roll.Next(, );
if (num > )
{
num -= ;
Manager.money += num;
Console.WriteLine("我是{0},我帮主人捡到了{1},我好开心!!", name, num);
}
else
{
Console.WriteLine("主人我没捡到钱,我的肉不好吃!!");
}
}
public void SayHello()
{
Console.WriteLine("主人,我是{0}", name);
}
}
#endregion
class Program
{
static void Main(string[] args)
{
#region 属性
Student xiaoMing = new Student("小明", , '男');
Console.WriteLine(xiaoMing.Name);
xiaoMing.Age = ;
Console.WriteLine(xiaoMing.Age);
#endregion
#region 属性的练习1
Student1 xiaoMing1 = new Student1("小明",'男', , , );
xiaoMing1.SayHello();
Console.WriteLine(xiaoMing1.Age);
Console.WriteLine(xiaoMing1.CSharp);
Console.WriteLine(xiaoMing1.Unity);
Console.WriteLine(xiaoMing1.Sex);
Console.WriteLine();
Student1 xiaoMing2 = new Student1("小明", '大', , , );
xiaoMing2.SayHello();
Console.WriteLine(xiaoMing2.Age);
Console.WriteLine(xiaoMing2.CSharp);
Console.WriteLine(xiaoMing2.Unity);
Console.WriteLine(xiaoMing2.Sex);
Console.WriteLine();
#endregion
#region 属性的练习2
Ticket t = new Ticket();
Console.WriteLine(t.Price);
Console.WriteLine(t);
#endregion
#region 属性的简写
Student2 xiaoMing2 = new Student2();
xiaoMing2.SayHello();
#endregion
#region 静态类
string ming = "赵钱孙李周吴郑王冯陈褚卫蒋沈韩杨";
Fighter[] monsters = new Fighter[];
for (int i = ; i < monsters.Length; i++)
{
monsters[i] = new Fighter("小" + ming[Manager.roll.Next(, ming.Length)]);
}
foreach (var item in monsters)
{
item.FindMoney();
}
Console.WriteLine(Manager.money);
#endregion
}
}
}
如何判定一个对象是被使用了?
结构体,在栈里读取数据
类,在栈里读取成员,在堆里读取数据(堆相当于内存条的大小)
结构体放在结构体里面,在栈里打开
结构体放在类里面,在堆里面打开
类,引用类型,直接储存的是地址,由CSharp的垃圾回收机制释放
结构体,值类型,直接存储的是数据
字符串,是特殊的引用类型,传参数时需要加ref
数组,在栈里存的是首元素的地址
堆里存储的对象数据,没有栈里的地址来指向(直接、间接),数据就会被垃圾回收机制回收
类里引用的是对象,结构体引用的不叫对象
析构函数,类似C++
析构函数可以监视,不可调用
参照《C#公共语言运行时》
拓展练习:乘客随着载具移动,乘客放在数组里面
属性
静态类
静态类占用静态空间
静态类,在程序开始时,会一直占用空间,直到程序结束时释放