Kotlin 使用Lambda来设置回调的操作

class MyBean {

  fun testcallback1(callback: (String) -> Unit) {
    callback.invoke("这是回调的内容")
  }

  fun testcallback2(value1: Int, value2: Int, callback: (Int, Int) -> Int): Int {
    var result = callback.invoke(value1, value2)
    return result * 3
  }
}

class MainActivity : AppCompatActivity() {

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)

    var bean = MyBean()
    bean.testcallback1 { m -> toast(m) }

    val result = bean.testcallback2(1, 2, { value1, value2 -> value1 + value2 })
    toast("计算结果" + result.toString())
  }
} 

interface CallBack{
  fun callBack(info : String)
}

class CallBacks : CallBack{
  override fun callBack(info : String){
    Log.d("MainApp","current info $info")
  }
}

private var mCallBack = object : CallBack{
  override fun callBack(info : String){
    Log.d("MainApp","current info $info")
  }
}

private fun initData(callBack : CallBack):Boolean{
  callBack?.callBack("我来自回调")
  return true
}