[Android] 定时器的实现（一）

向右看齐 2022-08-09 03:23 124阅读 0赞

## 1, Handler 加 Thread 的 sleep 方法 ##

public class MainActivity extends Activity {
        
    
        private Button mButton;
        private MyThread myThread = new MyThread();
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            mButton = (Button) findViewById(R.id.main_view_button);
    
            mButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    myThread.cancel();
                }
            });
    
            new Thread(myThread).start();
        }
    
        Handler handler = new Handler() {
            public void handleMessage(Message msg) {
                if (myThread.isCancel())
                    return;
    
                super.handleMessage(msg);
            }
        };
    
        public class MyThread implements Runnable {
        
    
            private boolean bCancel = false;
    
            @Override
            public void run() {
                while (true) {
                    try {
                        if (! isCancel()) {
                            // 线程暂停10s
                            Thread.sleep(10 * 1000);
                            Message message = Message.obtain();
                            message.what = 0x001;
                            handler.sendMessage(message);
                        }
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
    
            public boolean isCancel() {
                return bCancel;
            }
    
            public void cancel() {
                this.bCancel = true;
            }
        }
    }

## 2, Handler的postDelayed(Runnable, long)方法 ##

public class MainActivity extends Activity {
        
    
        Handler handler = new Handler();
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            handler.postDelayed(runnable, 10 * 1000);
        }
    
        Runnable runnable = new Runnable() {
    
            @Override
            public void run() {
                Log.v(TAG, "do some thing");
                handler.postDelayed(this , 10 * 1000);
            }
        };
    }

停止计时器

handler.removeCallbacks(runnable);

## 3. Handler + Timer + TimerTask ##

public class MainActivity extends Activity {
        
    
        private final Timer timer = new Timer();
        private TimerTask task = new TimerTask() {
    
            @Override
            public void run() {
                Message message = Message.obtain();
                message.what = 0x001;
                handler.sendMessage(message);
            }
        };
    
        Handler handler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                Log.v(TAG,"handleMessage");
                super.handleMessage(msg);
            }
        };
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            timer.schedule(task, 10000, 10000);
        }
    }

取消的方法：

timer.cancel()