android.os.MessageQueue.nativePollOnce 处的 ANR

**Android ANR现象及其原因分析**

java
public class MyTask extends AsyncTask {
    @Override
    protected Void doInBackground(Void... voids) {
        // 执行耗时操作
        return null;
    }
    
    @Override
    protected void onPostExecute(Void aVoid) {
        // 在主线程中更新UI
    }
}

java
public class MyThread extends Thread {
    private Handler handler;
    
    public MyThread(Handler handler) {
        this.handler = handler;
    }
    
    @Override
    public void run() {
        // 执行耗时操作
        
        // 将执行结果发送给主线程
        handler.sendEmptyMessage(0);
    }
}
Handler handler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        // 在主线程中更新UI
    }
};
MyThread thread = new MyThread(handler);
thread.start();