代理

by代理

只有接口才能实现by代理，类是不行的

fun BaseMain() {
    var dog = Animal("Dog")
    Delegation(dog).run()
}


class Animal(name: String) : IAniaml {
    var name = name
    override fun run() {
        println("This animal ${name}is running now.Please go for a look.")
    }
}

interface IAniaml {
    fun run()
}

class Delegation(a: IAniaml) : IAniaml by a

/**
打印 
This animal Dogis running now.Please go for a look.
*/

重写代理方法

当重写属性时，并不会改变传入的类的属性，如果前面有用到该类的方法时，不会受影响，

fun BaseMain() {
    var dog = Animal("Dog")
    var delDog = Delegation(dog)
    delDog.run()
    delDog.jump()
}


class Animal(override var name: String) : IAniaml {
    override fun jump() {
        println("I can jump,I can high.")
    }

    init {
        this.name = name
    }

    override fun run() {
        println("This animal ${name} is running now.Please go for a look.")
    }
}

interface IAniaml {
    var name: String
    fun run()
    fun jump()
}

class Delegation(a: IAniaml) : IAniaml by a {
    override var name = "Large Dog"
    override fun jump() {
        println("This is good at you. This is $name")
    }
}
/**
打印
This animal Dog is running now.Please go for a look.
This is good at you. This is Large Dog
*/

属性代理

• 一般情况

就是属性的监听器，虽然简单，但是还是有点不理解的是，不知道怎么获取属性值。。。。。fuck!

fun BaseMain() {
    var ani = Animal()
    ani.x = "this"
    println(ani.x)
    ani.x = "112"
}

class Animal {
    var x: String by Dog()
}

class Dog {
    operator fun getValue(thisRef: Any?, pr: KProperty<*>): String {
        return "This is  property name of ${pr.name}"
    }

    operator fun setValue(thisRef: Any?, property: KProperty<*>, value: String) {
        println("value is $value")
    }
}

• 其他见下节