Question

我有一个Android应用程序，我用MyApp.java启动我的应用程序，在那里我声明了所有内容，这是我的应用程序的起点。在onCreate()中，我有意图启动服务。

我还创建了一个服务实例，并尝试访问倒数计时器onFinish()内的服务对象，作为 -

MYService myService = new MYService();
myService.getDialog();

在MYService中，我将此方法设为 -

public void showMsg(){
        AlertDialog alertDialog = new AlertDialog.Builder(getApplication())
                .setTitle("Success!")
                .setMessage("Countdown")
                .setPositiveButton("Success", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                    }
                }).create();

        alertDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
        alertDialog.show();
    }

我的目标是我所在的应用程序中的任何一个部分，无论哪个活动或片段，我必须能够在倒数计时器5秒后获得此警报。我如何实现这一目标？

Answer 1

您可以使用BoundService：

创建核心活动，以便应用中的任何活动扩展核心活动。
将此核心活动绑定到您已创建的服务。
每当时间结束或计时器到期时，都会向核心活动发送消息。
当活动收到消息时，它会显示您的对话框。

您可以在此处引用此example。

查看here了解详情。

感谢。

Answer 2

在你的清单中

<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />

        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

<service
    android:name=".ShowAlertService"
    android:label="@string/app_name"/>

在您的MainActivity.JAVA

中

   import android.app.AlertDialog;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.v4.content.LocalBroadcastManager;
import android.support.v7.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

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

        Intent intent = new Intent(getApplicationContext(),ShowAlertService.class);
        startService(intent);

    }

    @Override
    public void onResume() {
        super.onResume();
        // This registers mMessageReceiver to receive messages.
        LocalBroadcastManager.getInstance(this)
                .registerReceiver(mMessageReceiver,
                        new IntentFilter("broadcastMsg"));
    }

    // Handling the received Intents for the "my-integer" event
    private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {

                   if(intent.getBooleanExtra("showalert",false))
                   {
                       showMsg();
                   }


        }
    };

    @Override
    protected void onPause() {
        // Unregister since the activity is not visible
        LocalBroadcastManager.getInstance(this)
                .unregisterReceiver(mMessageReceiver);
        super.onPause();
    }


    public void showMsg(){
        AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this)
                .setTitle("Success!")
                .setMessage("Countdown")
                .setPositiveButton("Success", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {

                    }
                }).create();
        alertDialog.show();
    }

}

最后你的服务类就像

   import android.app.Service;
import android.content.Intent;
import android.os.Handler;
import android.os.IBinder;
import android.support.v4.content.LocalBroadcastManager;
import android.util.Log;

import java.util.Timer;
import java.util.TimerTask;

public class ShowAlertService extends Service {

    Timer timer;
    TimerTask timerTask;
    String TAG = "Timers";
    int Your_X_SECS = 5;


    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.e(TAG, "onStartCommand");
        super.onStartCommand(intent, flags, startId);

        startTimer();

        return START_STICKY;
    }


    @Override
    public void onCreate() {
        Log.e(TAG, "onCreate");


    }

    @Override
    public void onDestroy() {
        Log.e(TAG, "onDestroy");
        stoptimertask();
        super.onDestroy();


    }

    //we are going to use a handler to be able to run in our TimerTask
    final Handler handler = new Handler();


    public void startTimer() {
        //set a new Timer
        timer = new Timer();

        //initialize the TimerTask's job
        initializeTimerTask();

        //schedule the timer, after the first 5000ms the TimerTask will run every 10000ms
        timer.schedule(timerTask, 5000, Your_X_SECS * 1000); //
        //timer.schedule(timerTask, 5000,1000); //
    }

    public void stoptimertask() {
        //stop the timer, if it's not already null
        if (timer != null) {
            timer.cancel();
            timer = null;
        }
    }

    public void initializeTimerTask() {

        timerTask = new TimerTask() {
            public void run() {

                //use a handler to run a toast that shows the current timestamp
                handler.post(new Runnable() {
                    public void run() {

                            sendMessage();

                    }
                });
            }
        };
    }

    //Send message to activity
    private void sendMessage() {
        Intent intent = new Intent("broadcastMsg");
        intent.putExtra("showalert",true);
        LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
    }

}

将广播消息“showalert”发送到活动，并在收到广播消息后立即显示警报。

来自app的任何部分的服务的AlertDialog

2 个答案: