使用Messenger类绑定服务显示时间

水深无声 2022-08-19 13:24 10阅读 0赞

1、布局文件

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="vertical" >
    
        <Button
            android:id="@+id/current_time"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="当前时间"
            android:textColor="@android:color/black"
            android:textSize="25dp" />
    
    </LinearLayout>

2、创建CurrentTimeService类，继承Service类，内部类IncomingHandler类继承Handler类

public class CurrentTimeService extends Service {
    
    	public static final int CURRENT_TIME = 0;
    	private class IncomingHandler extends Handler{
    		@Override
    		public void handleMessage(Message msg) {
    			if(msg.what==CURRENT_TIME){
    				Time time = new Time();//创建Time对象
    				time.setToNow();//设置时间为当前时间
    				String currentTime = time.format("%Y-%m-%d %H:%M:%S");//设置时间格式
    				Toast.makeText(CurrentTimeService.this, currentTime, Toast.LENGTH_SHORT).show();
    			}else{
    				super.handleMessage(msg);
    			}
    		}
    	}
    	@Override
    	public IBinder onBind(Intent intent) {
    		Messenger messenger = new Messenger(new IncomingHandler());
    		return messenger.getBinder();
    	}
    }

3、MainActivity

public class MainActivity extends Activity {
    	
    	Messenger messenger;
    	boolean bound;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
        }
        @Override
        protected void onStart() {
        	super.onStart();
        	Button button = (Button)findViewById(R.id.current_time);
        	button.setOnClickListener(new OnClickListener() {
    			@Override
    			public void onClick(View v) {
    				Intent intent = new Intent(MainActivity.this,CurrentTimeService.class);
    				bindService(intent,connection,BIND_AUTO_CREATE);//绑定服务
    				if(bound){
    					Message message = Message.obtain(null, CurrentTimeService.CURRENT_TIME, 0, 0);
                        try {
                            messenger.send(message);
                        } catch (RemoteException e) {
                            e.printStackTrace();
                        }
    				}
    			}
    		});
        }
        @Override
        protected void onStop() {
        	super.onStop();
        	if(bound){
        		bound = false;
        		unbindService(connection);//解绑定
        	}
        }
        private ServiceConnection connection = new ServiceConnection(){
        	public void onServiceConnected(android.content.ComponentName name, android.os.IBinder service) {
        		messenger = new Messenger(service);

<span style="white-space:pre">		</span>bound = true;
        	};
        	public void onServiceDisconnected(android.content.ComponentName name) {
        		messenger = null;
        		bound = false;
        	}
        };
    }

4AndroidManifest.xml

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[Center]: /images/20220731/4e15eecb7f0940f1bb027cab4bafb55c.png
[Center 1]: /images/20220731/c30053badd84487e839d6fa04bba2ed3.png