android 从 service 获取数据到 activity

比眉伴天荒 2022-07-19 05:08 172阅读 0赞

package com.websmithing.broadcasttest;
    
    import java.util.Date;
    
    import android.app.Service;
    import android.content.Intent;
    import android.os.Handler;
    import android.os.IBinder;
    import android.util.Log;
    
    public class BroadcastService  extends Service {
    	private static final String TAG = "BroadcastService";
    	public static final String BROADCAST_ACTION = "com.websmithing.broadcasttest.displayevent";
    	private final Handler handler = new Handler();
    	Intent intent;
    	int counter = 0;
    	
    	@Override
    	public void onCreate() {
    		super.onCreate();
    
        	intent = new Intent(BROADCAST_ACTION);	
    	}
    	
        @Override
        public void onStart(Intent intent, int startId) {
            handler.removeCallbacks(sendUpdatesToUI);
            handler.postDelayed(sendUpdatesToUI, 1000); // 1 second
       
        }
    
        private Runnable sendUpdatesToUI = new Runnable() {
        	public void run() {
        		DisplayLoggingInfo();    		
        	    handler.postDelayed(this, 10000); // 10 seconds
        	}
        };    
        
        private void DisplayLoggingInfo() {
        	Log.d(TAG, "entered DisplayLoggingInfo");
    
        	intent.putExtra("time", new Date().toLocaleString());
        	intent.putExtra("counter", String.valueOf(++counter));
        	sendBroadcast(intent);
        }
    	
    	@Override
    	public IBinder onBind(Intent intent) {
    		return null;
    	}
    
    	@Override
    	public void onDestroy() {		
            handler.removeCallbacks(sendUpdatesToUI);		
    		super.onDestroy();
    	}		
    }

package com.websmithing.broadcasttest;
    
    import android.app.Activity;
    import android.content.BroadcastReceiver;
    import android.content.Context;
    import android.content.Intent;
    import android.content.IntentFilter;
    import android.os.Bundle;
    import android.util.Log;
    import android.widget.TextView;
    
    public class BroadcastTest extends Activity {
    	private static final String TAG = "BroadcastTest";
    	private Intent intent;
    	
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
            
            intent = new Intent(this, BroadcastService.class);
        }
    
        private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
            	updateUI(intent);       
            }
        };
        
    	@Override
    	public void onResume() {
    		super.onResume();		
    		startService(intent);
    		registerReceiver(broadcastReceiver, new IntentFilter(BroadcastService.BROADCAST_ACTION));
    	}
    	
    	@Override
    	public void onPause() {
    		super.onPause();
    		unregisterReceiver(broadcastReceiver);
    		stopService(intent); 		
    	}	
    	    
        private void updateUI(Intent intent) {
        	String counter = intent.getStringExtra("counter"); 
        	String time = intent.getStringExtra("time");
        	Log.d(TAG, counter);
        	Log.d(TAG, time);
        	
        	TextView txtDateTime = (TextView) findViewById(R.id.txtDateTime);  	
        	TextView txtCounter = (TextView) findViewById(R.id.txtCounter);
        	txtDateTime.setText(time);
        	txtCounter.setText(counter);
        }
    }

选自：https://www.websmithing.com/2011/02/01/how-to-update-the-ui-in-an-android-activity-using-data-from-a-background-service/comment-page-1/\#comment-734