使用BroadCast 使 service 和activity 信息交互

最新推荐文章于 2025-12-05 09:24:48 发布

最新推荐文章于 2025-12-05 09:24:48 发布 · 76 阅读

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本文介绍了一个Android应用中如何使用BroadcastReceiver来发送和接收广播。通过示例代码详细展示了注册广播接收器、发送广播消息的过程，并解释了如何在服务中启动广播以更新UI组件。

package com.su.testbroadcast;

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.widget.TextView;

public class TestBroadCastActivity extends Activity {
	private TextView textView;
	private ChangeReceiver changeReceiver;

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		textView = (TextView) findViewById(R.id.textView1);
		registerBroadcast();

		Intent service = new Intent(TestBroadCastActivity.this, MyService.class);
		startService(service);

	}
	
	@Override
	protected void onDestroy() {
		// TODO Auto-generated method stub
		super.onDestroy();
		unregisterReceiver(changeReceiver);//解除接受者
	}

/**
 *  为BroadcastReceiver指定action，使之用于接收同action的广播
 */
	private void registerBroadcast() {
		
		IntentFilter intentFilter = new IntentFilter();
		intentFilter.addAction("com.su.testbroadcast"); 
		changeReceiver = new ChangeReceiver();
		registerReceiver(changeReceiver, intentFilter);
	}

	
	public class ChangeReceiver extends BroadcastReceiver {//实现接受者

		@Override
		public void onReceive(Context context, Intent intent) {
			String title = intent.getStringExtra("msg");
			textView.setText(title);

		}

	}

}

package com.su.testbroadcast;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;

public class MyService extends Service {

	@Override
	public void onCreate() {
		super.onCreate();
		//發送廣播
		Intent intent = new Intent("com.su.testbroadcast");
		intent.putExtra("msg", "msg from service");
		sendBroadcast(intent);
	}

	@Override
	public IBinder onBind(Intent intent) {
		// TODO Auto-generated method stub
		return null;
	}

}