廣播接收器BroadcastReceiver練習

1.定義接受廣播的類

package mars.com;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.widget.Toast;public class MyReceiver extends BroadcastReceiver {@Overridepublic void onReceive(Context context, Intent intent) {String str;str = "接收到的訊息:" + intent.getStringExtra("message");Toast.makeText(context, str, Toast.LENGTH_SHORT).show();}}

2.activity類

package mars.com;import android.app.Activity;import android.content.Intent;import android.content.IntentFilter;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class DemoBroadcastReceiverActivity extends Activity {private Button button1;private Button button2;private Button button3;public MyReceiver receiver;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);button1 = (Button) findViewById(R.id.button1);button2 = (Button) findViewById(R.id.button2);button3 = (Button) findViewById(R.id.button3);button1.setOnClickListener(new OnClickListener() {public void onClick(View v) {Intent intent = new Intent();intent.setAction("mars.com");intent.putExtra("message", "來自於廣播的訊息");sendBroadcast(intent);}});button2.setOnClickListener(new OnClickListener() {public void onClick(View v) {IntentFilter filter = new IntentFilter("mars.com");receiver = new MyReceiver();registerReceiver(receiver, filter);// 註冊廣播接收器}});button3.setOnClickListener(new OnClickListener() {public void onClick(View v) {unregisterReceiver(receiver);// 銷毀廣播接收器}});}}

3.千萬別忘了註冊廣播接收器

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="mars.com"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk android:minSdkVersion="8" />    <application        android:icon="@drawable/ic_launcher"        android:label="@string/app_name" >        <activity            android:name=".DemoBroadcastReceiverActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <receiver android:name="MyReceiver" >            <intent-filter>                <action android:name="mars.com" />            </intent-filter>        </receiver>    </application></manifest>

<receiver android:name="MyReceiver" >
            <intent-filter>
                <action android:name="mars.com" />
            </intent-filter>

</receiver>