Kotlin中的sam(函数式接口)详解

Button.setOnClickListener(new OnClickListener()){
  @Override
  public void onClick(View v){
    Toast.makeText(this,"Hello World",Toast.LENGTH_LONG).show()
  }
}

btn_test.setOnClickListener { view : View ->
      Toast.makeText(this,"Hello World",Toast.LENGTH_LONG).show()
}

void postponeComputation(int delay,Runnable computation){
}

postponeComputation(1000){
    print("hello world")
}

postponeComputation(1000,object : Runnable{
    override fun run(){
        println(42)
    }
})

val runnable = Runaable{ println(42) }
fun handleComputation(){
   postponeComputation(1000,runnable)
}

fun handleComputation(id : String){
   postponeComputation(1000){println(id)}
}

fun createAllDoneRunable() : Runnable{
  return Runnable{ println(“All done”) }
}

val listener = OnClickListener{
  view -> val text = when(view.id){
    R.id.button1 -> “First button”
    R.id.button2 -> “Second button”
    else -> “Unknown button"
  }
  toast(text)
}
button1.setOnClickListener(listener)
button2.setOnClickListener(listener)