Android 定时器的三种实现方法

刺骨的言语ヽ痛彻心扉 2022-07-13 00:00 230阅读 0赞

# Android 定时器的三种实现方法 #

## 第一种:采用Handler与线程的sleep(long)方法 ##

“\`JAVA  
public class MainActivity extends Activity \{  
Handler handler;  
private TextView tv;  
int i = 0;

public boolean isstop = false;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tv);
    
        // 定时器的三种实现方法
        // -----------------------------------------------------------------------------
        // 第一种:采用Handler与线程的sleep(long)方法
    
        handler = new Handler() {
            public void handleMessage(android.os.Message msg) {
                tv.setText(i++ + "");
    
                // 开启定时器线程
                new Thread(new MyThread()).start();
    
            };
    
        };
    
    }
    
    public void start(View view) {
        isstop = false;
        // 开启定时器线程
        new Thread(new MyThread()).start();
    
    }
    
    // 停止
    public void stop(View view) {
        isstop = true;
    
    }
    
    class MyThread implements Runnable {
    
        @Override
        public void run() {
            if (!isstop) {
    
                // TODO Auto-generated method stub
                try {
                    Thread.sleep(1 * 1000);
                    Message msg = new Message();
                    msg.what = 1;
                    handler.sendMessage(msg);
    
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
    
        }
    
    }

“

![Image 1][]

## 第二种:采用Handler的postDelayed(Runnable, long)方法 ##

“\`java

public class MainActivity extends Activity \{  
Handler handler;  
private TextView tv;  
int i = 0;  
Runnable runnable;

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tv);
    
        handler = new Handler();
        runnable = new Runnable() {
            @Override
            public void run() {
                // TODO Auto-generated method stub
                // 要做的事情
                tv.setText(i++ + "");
                handler.postDelayed(runnable, 2 * 1000);
            }
        };
    
    }
    
    public void start(View view) {
        // 开启定时器线程
        handler.postDelayed(runnable, 2 * 1000);//两秒后执行一次runnable的 run() 方法.
    
    }
    
    // 停止
    public void stop(View view) {
        handler.removeCallbacks(runnable);
    }

[Image 1]: