android - 服务和广播接收器

Question

我已经看到了几个如何实现 BroadCastReceiver 的示例，但是我应该如何实现一个必须对一些待处理的 Intent（例如来电）做出反应的服务......实际上我想知道同样的“问题”但是在一个活动..您显然有一个扩展服务或活动的类）所以它也不能扩展广播接收器......看起来我们不能制作“平台感知”服务和/或活动？

Answer 1

要注册活动以接收特定意图，您需要：

// Flag if receiver is registered 
private boolean mReceiversRegistered = false;

// I think this is the broadcast you need for something like an incoming call
private String INCOMING_CALL_ACTION = "android.intent.action.PHONE_STATE";

// Define a handler and a broadcast receiver
private final Handler mHandler = new Handler();
private final BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {
  @Override
  public void onReceive(Context context, Intent intent) {
    // Handle reciever
    String mAction = intent.getAction();

    if(mAction.equals(INCOMING_CALL_ACTION) {
      // Do your thing   
    }
}

@Override
protected void onResume() {
  super.onResume();

  // Register Sync Recievers
  IntentFilter intentToReceiveFilter = new IntentFilter();
  intentToReceiveFilter.addAction(INCOMING_CALL_ACTION);
  this.registerReceiver(mIntentReceiver, intentToReceiveFilter, null, mHandler);
  mReceiversRegistered = true;
}

@Override
public void onPause() {
  super.onPause();

  // Make sure you unregister your receivers when you pause your activity
  if(mReceiversRegistered) {
    unregisterReceiver(mIntentReceiver);
    mReceiversRegistered = false;
  }
}

然后，您还需要在清单中添加一个意图过滤器：

 <activity android:name=".MyActivity" android:label="@string/name" >
   <intent-filter> 
     <action android:name="android.intent.action.PHONE_STATE" /> 
   </intent-filter>
 </activity>

Answer 2

你可以创建一个内部类

class A extends Activity {
 BroadcastReceiver r = new BroadcastReceiver(){
   // code to handle broadcase
 }
}

该类将接收事件，您可以将其传递给主处理程序，或者只是调用一些外部方法

Answer 3

实际上，您只需将侦听器添加到 TelephonyManager 即可对来电做出反应

您在 Service/Activity 中定义 PhoneStateListener

private PhoneStateListener mPhoneStateListener = new PhoneStateListener() {

    @Override
    public void onCallStateChanged(int state, String incomingNumber) {
        super.onCallStateChanged(state, incomingNumber);

        switch (state) {
        case TelephonyManager.CALL_STATE_OFFHOOK:
                     break;
        case TelephonyManager.CALL_STATE_RINGING:
                     break;
        case TelephonyManager.CALL_STATE_IDLE:
                     break;
        }
    }

};

然后在 onCreate 方法中：

mTelephonyManager = (TelephonyManager) getSystemService(TELEPHONY_SERVICE);
mTelephonyManager.listen(mPhoneStateListener, PhoneStateListener.LISTEN_CALL_STATE);

最后你清除 onDestroy 中的监听器：

mTelephonyManager.listen(mPhoneStateListener, PhoneStateListener.LISTEN_NONE);

在这种情况下要简单得多。