Question

我正在尝试使用brodcast

将值从服务传递到活动

我正在使用以下代码在服务中调用brodcast

            Intent i = new Intent();
            i.putExtra("test",result);
            sendBroadcast(i);

使用以下代码接收主要活动

     public class myreciver extends BroadcastReceiver{
            public String data =null;
            @Override
        public void onReceive(Context context, Intent intent) {
                String action = intent.getAction();
                String datapassed = intent.getStringExtra("test");

         }
 }

主要活动

             myreciver m = new myreciver();
             IntentFilter intentFilter = new IntentFilter();
             intentFilter.addAction(MyService.MY_ACTION);
             registerReceiver(m, intentFilter);

但我的收件人没有被叫。

清单文件

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        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=".MainActivity$myreciver" >
    </receiver>

    <service
        android:name=".MyIntentService"
        android:exported="false" >
    </service>
    <service
        android:name=".MyService"
        android:enabled="true"
        android:exported="false" >
    </service>

    <activity
        android:name=".display"
        android:label="@string/title_activity_display" >
    </activity>
</application>

Answer 1

传递给sendBroadcast方法的Intent中缺少

动作，因为：

Intent i = new Intent(MyService.MY_ACTION); //<< pass Action to Intent
i.putExtra("test",result); 
sendBroadcast(i);

Answer 2

使用像这样的广播

 Intent i = new Intent("Broadcastname");

            context.sendBroadcast(i);

现在以这种方式接收广播

@Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();
        IntentFilter intentFilter = new IntentFilter("Broadcastname");
    BroadcastReceiver   Receiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {

                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        // TODO Auto-generated method stub
                        // to your work here 

                    }
                });

            }
        };

    this.registerReceiver(Receiver, intentFilter);

最后在onstop（）方法中取消注册

@Override
    protected void onStop() {
        // TODO Auto-generated method stub

        if (Receiver != null) {
            this.unregisterReceiver(this.Receiver);
        }
        super.onStop();
    }

Answer 3

Android BroadcastReceiver是框架的一部分，允许活动和服务相互发送数据，即使它们属于不同的应用程序。这是应用程序彼此共享数据的方式，例如当您将图片库中的图片共享到Facebook或G +时。但是，这种广泛的功能意味着您必须小心如何过滤请求，这意味着从您自己的应用程序内部发送快速消息可能更难。

如果您不需要担心从其他应用程序接收数据，那么您可以使用LocalBroadcastManager，这是BroadcastReceiver的实施，仅限于您自己应用的管辖范围内。它无法从您的应用外部发送或接收意图。它的界面几乎与BroadcastReceiver的相同：

public class MyActivity extends Activity {

  private LocalBroadcastManager mBroadcastManager;

  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    mBroadcastManager = LocalBroadcastManager.getInstance(this);

    //Build an intent filter so you only receive relevant intents
    IntentFilter intentFilter = new IntentFilter();
    intentFilter.addAction("Test from Service to Activity");

    //Register a new BroadcastReceiver with the LocalBroadcastManager
    mBroadcastManager.registerReceiver(new BroadcastReceiver() {
      @Override
      public void onReceive(Context context, Intent intent) {

        String action = intent.getAction();
        String dataPassed = intent.getStringExtra("test");

      }                               
    }, intentFilter);

    //If you ever want to send a broadcast, use this:
    Intent sendIntent = new Intent(this, MyService.class);
    sendIntent.setAction("Test from Activity to Service");
    sendIntent.putExtra("test", "This is a test from Activity!");
    mBroadcastManager.sendBroadcast(sendIntent);
  }
}

//Then in your Service...

public class MyService extends Service {

  private LocalBroadcastManager mBroadcastManager;

  public void onCreate() {
    mBroadcastManager = LocalBroadcastManger.getInstance(this);
  }

  public int onStartCommand(Intent intent, int flags, int startId) {

    //Build intent filter
    IntentFilter intentFilter = new IntentFilter();
    intentFilter.addAction("Test from Activity to Service");

    mBroadcastManger.registerReceiver(new BroadcastReceiver() {
      @Override
      public void onReceive(Context context, Intent intent) {

        String action = intent.getAction();
        String dataPassed = intent.getStringExtra("test");

      }

    }, intentFilter);

    //To send data to the activity:
    Intent sendIntent = new Intent(this, MyActivity.class);
    sendIntent.setAction("Test from Service to Activity");
    sendIntent.putExtra("test", "This is a test from Service!");
    mBroadcastManager.sendBroadcast(sendIntent);
  }
}

Brodcastreciver没有接受

3 个答案: