【Kotlin】Kotlin笔记8-Lambda编程3(Java的函数式API)

Kotlin笔记8-Lambda编程3-Java的函数式API

4.3 Lambda编程3

• Java的函数式API

​​Example-Java:​​

interface Runnable {
    void run();
}

new Thread(Runnable() {
    @Override
    public void run() {
        System.out.println("Thread is running");
    }
}).start();

​​Kotlin:​​

Thread(object : Runnable {
    override fun run() {
        println("Thread is running!")
    }
}).start()

简化过程

​​单独方法run,没有显示重写:​​

Thread(Runnable {
    println("Thread is running!")
}).start()

​​参数列表唯一,接口名省略:​​

Thread({
  println("Thread is running!")
}).start()

​​表达式移到括号外,括号省略:​​

Thread{ println("Thread is running!") }.start()

实用场景
​​​OnClickListener-Java:​​

public interface OnClickListener {
  void onClick(View v);
}

​​kotlin:​​

button.setOnClickListener {
}