如何在不使用onCreate()的情况下将数据从BroadcastReceiver传递到Activity [英] How to pass data from BroadcastReceiver to Activity without in onCreate()

问题描述

我对将数据从BroadcastReceiver传递到Activity有一个严重的问题.让我们仔细看看我的问题.我有一个PhoneStateReceiver extends BroadcastReceiver类别，该类别曾经用来接收传入的电话.

I have a serious issue about passing data from BroadcastReceiver to an Activity. Let see my issue carefully. I have a class PhoneStateReceiver extends BroadcastReceiver that used to received an incoming phone.

public class PhoneStateReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        try {
            System.out.println("Receiver start");
            String state = intent.getStringExtra(TelephonyManager.EXTRA_STATE);
            String incomingNumber = intent.getStringExtra(TelephonyManager.EXTRA_INCOMING_NUMBER);
            if(state.equals(TelephonyManager.EXTRA_STATE_RINGING)){

            }            
        }
        catch (Exception e){
            e.printStackTrace();
        }
    }
}

传入电话将被发送到名为ReceiverActivity的Activity. ReceiverActivity接收传入的电话，并通过套接字连接将其发送到服务器.套接字连接在onCreate函数中初始化.我在Google上搜索并找到了将数据从BroadcastReceiver传递到Activity的服务器方法.常见的方法是通过putExtra函数发送数据并调用startActivity.但是，该方式将再次调用onCreate，然后连接套接字，再次绘制UI.因此，这对我的情况没有帮助.

The incoming phone will be sent to an Activity, called ReceiverActivity. The ReceiverActivity receives the incoming phone and sends it to a server via a socket connection. The socket connection is initialized in the onCreate function. I googled and found server way to pass the data from BroadcastReceiver to an Activity. The common way is that send data via putExtra function and call startActivity. However, the way will call the onCreate again and then connect the socket, draw the UI again. Thus, it is not helpful in my case.

在我的目标中，如果电话收到来电，它将把来电发送到ReceiverActivity. ReceiverActivity接收消息并调用发送功能.哪个是最好的方法?谢谢

In my goal, If the phone receives an incoming call, it will send the incoming call to the ReceiverActivity. The ReceiverActivity receives the message and calls the send function. Which is the best way to do it? Thank you

将数据从BroadcastReceiver传递到ReceiverActivity的常用方法，如下所示:

The common way to pass data from a BroadcastReceiver to a ReceiverActivity that I used as follows

在 PhoneStateReceiver 类中:

Intent intent_phonenum = new Intent(context, ReceiverActivity.class);
intent_phonenum.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent_phonenum.putExtra("phone_num", incomingNumber);
context.startActivity(intent_phonenum);

在 ReceiverActivity 类中:

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        connect_socket();
        Intent intent = getIntent();
        phone_num = intent.getStringExtra("phone_num");
        send(phone_num);
}

推荐答案

有一个非常简单的设计模式，您可以在这里使用它来简化类之间的通信，并解耦代码:publisher/subscriber.我最喜欢的库是EventBus:

There is a very simple design pattern you can use here to ease communication between your classes and also decouple your code: publisher/subscriber. My favorite library for this is EventBus:

首先，将其添加到您的 build.gradle 文件中:

First, add to your build.gradle file:

compile 'org.greenrobot:eventbus:3.0.0'

然后，像这样创建一个简单的POJO - Plain Old Java Object:

Then, create a simple POJO - Plain Old Java Object like this:

public class OnReceiverEvent{
   private String phoneNumber;

   public OnReceiverEvent(String phone){
      this.phoneNumber = phone;
   }

   public String getPhoneNumber(){
      return phoneNumber;
   }
}

接下来，通过将Receiver类设置为publisher，将Activity类设置为subscriber，您应该能够轻松地将信息传递给活动，如下所示:

Next, by making your Receiver class a publisher, and your Activity a subscriber, you should be able to easily pass the information to your activity like this:

//inside your PhoneStateReceiver class when you want to pass info

EventBus.getDefault().post(new OnReceiverEvent(phoneNumber));

接下来，在您的活动中，只需执行以下操作:

Next, inside your activity, simply do this:

//onStart
@Override
public void onStart(){
   super.onStart();
   EventBus.getDefault().register(this);
}

//onStop
@Override
public void onStop(){
   super.onStop();

   EventBus.getDefault().unregister(this);
}

最后，处理发布的数据，即phoneNumber值:

Finally, handle the posted data i.e phoneNumber value:

@Subscribe
public void onPhoneNumberReceived(OnReceiverEvent event){
   //get the phone number value here and do something with it

   String phoneNumber = event.getPhoneNumber();

   //display or something?
}

更新

如果您要订阅此活动的另一个事件，只需使用@Subscribe注释创建与第一个事件类似的方法即可.

If you have another Event that you want this activity to subscribe to, simply create a method like you did in the first one using the @Subscribe annotation.

@Subscribe
public void onSomeOtherEvent(EventClassName event){
   //get the variables here as usual;
}

这是将数据从接收器传递到活动的最简单方法，而不必担心一遍又一遍地开始活动！

This is the easiest way to pass the data from your receiver to your activity without having to worry about starting the activity over and over!

我希望这会有所帮助，祝你好运！

I hope this helps and good luck!

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