使用Executor而不是handler获取更多信息。 使用ScheduledExecutorService实现post delay:

ScheduledExecutorService worker = Executors.newSingleThreadScheduledExecutor();
Runnable runnable = () -> {
    public void run() {
        // Do something
    }
};
worker.schedule(runnable, 2000, TimeUnit.MILLISECONDS);

考虑使用协程

scope.launch {
    delay(3000L)
    // do stuff
}

根据文档(https://developer.android.com/reference/android/os/Handler#Handler()):

Implicitly choosing a Looper during Handler construction can lead to bugs where operations are silently lost (if the Handler is not expecting new tasks and quits), crashes (if a handler is sometimes created on a thread without a Looper active), or race conditions, where the thread a handler is associated with is not what the author anticipated. Instead, use an Executor or specify the Looper explicitly, using Looper#getMainLooper, {link android.view.View#getHandler}, or similar. If the implicit thread local behavior is required for compatibility, use new Handler(Looper.myLooper()) to make it clear to readers.

我们应该停止使用没有Looper的构造函数，而是指定一个Looper。

对于Xamarin Android，而不是

Handler handler;
handler = new Handler();

只写

Handler handler;
handler = new Handler(Looper.MyLooper());

其余的代码都很好。

如果你使用变量作为处理程序和可运行的，然后像这样使用它。

private Handler handler;
private Runnable runnable;

handler = new Handler(Looper.getMainLooper());
    handler.postDelayed(runnable = () -> {
        // Do delayed stuff here
         handler.postDelayed(runnable, 1000);
    }, delay);

你还需要删除onDestroy()中的回调

@Override
public void onDestroy() {
    super.onDestroy();
    if (handler != null) {
        handler.removeCallbacks(runnable);
    }
}

在Handler构造函数中提供一个循环器

Handler(Looper.getMainLooper())