安卓消息机制（单个线程倒计时结束后重启的方法）

public class MainActivity extends AppCompatActivity { private Button btn_start; private TextView tv_time; private MyThread thread=null; public int num=10; public static final int WHAT=1; private MyHandle handle=null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); btn_start= (Button) findViewById(R.id.btn_start); tv_time= (TextView) findViewById(R.id.tv_time); btn_start.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //启动子线程发送Message if(thread==null){ thread=new MyThread(); thread.start(); } } }); if(handle==null){ handle=new MyHandle(); } } class MyThread extends Thread{ @Override public void run() { super.run(); while (!Thread.interrupted()){ while (num>=0){ Message message= handle.obtainMessage(WHAT,String.valueOf(num)); handle.sendMessage(message); try { Thread.sleep(1000); } catch (InterruptedException e) { e.printStackTrace(); } num--; } //线程结束后重启线程的办法 if(num<0){ thread.interrupt();//线程中断 thread=null; num=10; } } } } class MyHandle extends Handler{ @Override public void handleMessage(Message msg) { super.handleMessage(msg); switch (msg.what){ case WHAT: tv_time.setText(msg.obj.toString()); break; } } }