java使用Runnable to lambda表达式升级处理程序

Question

我想升级此代码以使用lambda表达式：

Handler handler = new Handler(Looper.getMainLooper());
handler.postDelayed(new Runnable() {
    @Override
    public void run() {
        missileX = ufoX;
        resetRecent();
        waitForUfoTimer = false;
    }
}, randomize(20000, 18000));

我用这种方式尝试，但它无法编译：

Handler handler2 = new Handler(Looper.getMainLooper());
handler2.postDelayed(Runnable task = () -> {  
    missileX = ufoX;
    resetRecent();
    waitForUfoTimer = false; 
  }
}, randomize(20000, 18000));

哪里有一些说明，我可以学习如何做？我必须猜测语法是荒谬的

Answer 1

您不必声明要分配给lambda的变量。这就足够了：

Handler handler2 = new Handler(Looper.getMainLooper());
handler2.postDelayed(() -> {  
    missileX = ufoX;
    resetRecent();
    waitForUfoTimer = false; 
  }
, randomize(20000, 18000));