Question

无论何时收到短信，我都想要留言。

我尝试明确地将意图过滤器放在清单中并且我部分成功，除了我不想在应用程序被杀时调用它，所以在这里的一些程序员的建议下，我尝试通过在我的用户界面中放置两个按钮（即register和unregister来以编程方式制作广播接收器，因此它们的唯一目的是注册和取消注册广播接收器。

我的主要目的是即使应用程序是后台运行广播接收器（满足条件，用户按下注册表以及使用其他应用程序后）。
我一直在使用这个教程：http://www.javacodegeeks.com/2012/09/android-broadcast-receiver.html，但基本上用sms接收器修改它。

这是我的代码：

package gates.apps.automaticmessageresponder;

import android.app.Activity;
import android.content.ComponentName;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;

 public class MainActivity extends Activity {

SmsReceiver broadcastReceiver=new SmsReceiver();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

public void register(View view){

    this.registerReceiver(broadcastReceiver, new IntentFilter(
             "android.provider.Telephony.SMS_RECEIVED"));
    Log.e("register","pressed");  

}
public void unRegister(View view){

     this.unregisterReceiver(broadcastReceiver);
     Log.e("unregister","pressed");

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

另一个班级

package gates.apps.automaticmessageresponder;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.SmsManager;
import android.telephony.SmsMessage;
import android.util.Log;
import android.widget.Toast;

public class SmsReceiver extends BroadcastReceiver {

// Get the object of SmsManager
final SmsManager sms = SmsManager.getDefault();

@Override
public void onReceive(Context context, Intent intent) {
    // TODO Auto-generated method stub

    // Retrieves a map of extended data from the intent.
    final Bundle bundle = intent.getExtras();

    try {

        if (bundle != null) {

            final Object[] pdusObj = (Object[]) bundle.get("pdus");

            for (int i = 0; i < pdusObj.length; i++) {

                SmsMessage currentMessage = SmsMessage.createFromPdu((byte[]) pdusObj[i]);
                String phoneNumber = currentMessage.getDisplayOriginatingAddress();

                String senderNum = phoneNumber;
                String message = currentMessage.getDisplayMessageBody();

                Log.i("SmsReceiver", "senderNum: "+ senderNum + "; message: " + message);


               // Show alert
                int duration = Toast.LENGTH_LONG;
                Toast toast = Toast.makeText(context, "senderNum: "+ senderNum + ", message: " + message, duration);
                toast.show();

            } // end for loop
          } // bundle is null

    } catch (Exception e) {
        Log.e("SmsReceiver", "Exception smsReceiver" +e);
    }
}
}

我没有修改清单文件，只是我添加了接收短信的权限。即使我进入日志，寄存器按下和未按下。我认为问题在于注册接收器按钮即使没有点击也被调用，这是一种异常行为吗？或者我的看法是错的？

Answer 1

不要在清单中声明BroadcastReceiver，而是在活动中尝试如下，这会将其与Activity生命周期联系起来（不要忘记在清单文件中添加权限）：

public class ExampleMainActivity extends Activity {

   //Activity Stuff

   private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, final Intent intent) {

            //Do things you want with message.

            AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
            builder.setTitle("Title");
            builder.setMessage("You may add your things here");
            builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {

                    dialog.dismiss();
                }
            });
            builder.show();
        }
    };

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

        // OR YOU CAN REGISTER UNREGISTER AS YOU WANT

        this.registerReceiver(broadcastReceiver, new IntentFilter(
                 "android.provider.Telephony.SMS_RECEIVED"));
    };

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

         // OR YOU CAN REGISTER UNREGISTER AS YOU WANT

         this.unregisterReceiver(broadcastReceiver);
    }
}

修改：

您可以使用应用程序首选项检查此交替解决方案：

package gates.apps.automaticmessageresponder;

import android.app.Activity;
import android.content.ComponentName;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;

 public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

public void register(View view){

    SharedPreferences preferences = context.getSharedPreferences("FILE_NAME", Context.MODE_PRIVATE);
    Editor edit = preferences.edit();
    edit.putBoolean("isRegistered", true);
    edit.commit();

    Log.e("register","pressed");  

}
public void unRegister(View view){

    SharedPreferences preferences = context.getSharedPreferences("FILE_NAME", Context.MODE_PRIVATE);
    Editor edit = preferences.edit();
    edit.putBoolean("isRegistered", false);
    edit.commit();

     Log.e("unregister","pressed");

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

并且

package gates.apps.automaticmessageresponder;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.SmsManager;
import android.telephony.SmsMessage;
import android.util.Log;
import android.widget.Toast;

public class SmsReceiver extends BroadcastReceiver {

// Get the object of SmsManager
final SmsManager sms = SmsManager.getDefault();

@Override
public void onReceive(Context context, Intent intent) {
    // TODO Auto-generated method stub

    // Retrieves a map of extended data from the intent.
    final Bundle bundle = intent.getExtras();

    try {

        if (bundle != null) {

            final Object[] pdusObj = (Object[]) bundle.get("pdus");

            for (int i = 0; i < pdusObj.length; i++) {

                SmsMessage currentMessage = SmsMessage.createFromPdu((byte[]) pdusObj[i]);
                String phoneNumber = currentMessage.getDisplayOriginatingAddress();

                String senderNum = phoneNumber;
                String message = currentMessage.getDisplayMessageBody();

                Log.i("SmsReceiver", "senderNum: "+ senderNum + "; message: " + message);

        SharedPreferences preferences = context.getSharedPreferences("FILE_NAME", Context.MODE_PRIVATE);
        boolean isRegistered = preferences.getBoolean("isRegistered", false);

                if(isRegistered ) {
                    // Show alert
                    int duration = Toast.LENGTH_LONG;
                    Toast toast = Toast.makeText(context, "senderNum: "+ senderNum + ", 
                                        message: " + message, duration);
                    toast.show();
        }

            } // end for loop
          } // bundle is null

    } catch (Exception e) {
        Log.e("SmsReceiver", "Exception smsReceiver" +e);

    }

}

}

Answer 2

这不起作用的原因是因为注册/取消注册与活动生命周期无关，可能会使多个广播接收器被注册。请考虑以下情况：

用户导航到MainActivity，然后点击“注册”按钮。然后，用户离开活动（没有取消注册），应用程序可能没有被杀死。请注意，您的广播接收器仍在注册。

然后，稍后，用户导航回活动并再次注册。现在，您有两个不同的广播接收器在侦听操作。你几乎泄露了一个接收器。

解决方案：在清单中注册您的接收器。使用共享首选项键/值对保存注册按钮单击。然后，当你在onReceive上被调用时，使用键/值对状态来确定你是否想要Toast。

Intent过滤器甚至不以编程方式取消注册

2 个答案: