我按照this开发人员教程，按照预期在我的应用中使用Geofencing。
在IntentService：
@Override
protected void onHandleIntent(Intent intent) {
GeofencingEvent geofencingEvent = GeofencingEvent.fromIntent(intent);
...
sendNotification(geofenceTransitionDetails);
}
private void sendNotification(String notificationDetails) {
// Create an explicit content Intent that starts the main Activity.
Intent notificationIntent = new Intent(getApplicationContext(), MainActivity.class);
// Construct a task stack.
TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
// Add the main Activity to the task stack as the parent.
stackBuilder.addParentStack(MainActivity.class);
// Push the content Intent onto the stack.
stackBuilder.addNextIntent(notificationIntent);
// Get a PendingIntent containing the entire back stack.
PendingIntent notificationPendingIntent =
stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT);
// Get a notification builder that's compatible with platform versions >= 4
NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
// Define the notification settings.
builder.setSmallIcon(R.mipmap.ic_launcher)
// In a real app, you may want to use a library like Volley
// to decode the Bitmap.
.setLargeIcon(BitmapFactory.decodeResource(getResources(),
R.mipmap.ic_launcher))
.setColor(Color.RED)
.setContentTitle(notificationDetails)
.setContentText("Return to app")
.setContentIntent(notificationPendingIntent);
// Dismiss notification once the user touches it.
builder.setAutoCancel(true);
// Get an instance of the Notification manager
NotificationManager mNotificationManager =
(NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
// Issue the notification
mNotificationManager.notify(0, builder.build());
}
这是教程中的千篇一律。意图在主要活动中设置：
private PendingIntent getGeofencePendingIntent() {
// Reuse the PendingIntent if we already have it.
if (mGeofencePendingIntent != null) {
return mGeofencePendingIntent;
}
Intent intent = new Intent(this, GeofenceTransitionsIntentService.class);
// We use FLAG_UPDATE_CURRENT so that we get the same pending intent back when calling
// addGeofences() and removeGeofences().
return PendingIntent.getService(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
}
如果应用程序处于打开状态，如何添加禁止通知的功能，而是向用户显示AlertDialog？理想情况下，我希望能够执行不同的任务，具体取决于发生地理围栏转换时用户当前所处的视图。我可以监控/拦截每个视图中的转换，还是以某种方式全局监控？
提前致谢。
答案 0 :(得分：7)
有些答案是不完整的，所以这里是我正在寻找的完整解决方案。
首先，设置MyApplication类，实现ActivityLifecycleCallbacks：
public class MyApplication extends Application implements Application.ActivityLifecycleCallbacks {
private static boolean isActive;
@Override
public void onCreate() {
super.onCreate();
registerActivityLifecycleCallbacks(this);
}
public static boolean isActivityVisible(){
return isActive;
}
@Override
public void onActivityResumed(Activity activity) {
isActive = true;
}
@Override
public void onActivityPaused(Activity activity) {
isActive = false;
}
... no other methods need to be used, but there are more that
... must be included for the ActivityLifecycleCallbacks
}
请务必在清单中命名（仅添加名称行，默认为休息）：
<application
android:name=".MyApplication"
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme"
android:hardwareAccelerated="true">
上面所做的工作用于跟踪应用的生命周期。您可以使用它来检查您的应用当前是否在前台。
接下来是设置BroadcastReceiver，无论您希望代码运行在哪里（如果应用程序在触发器发生时打开）。在这种情况下，它位于我的MainActivity：
protected BroadcastReceiver mNotificationReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
... Do whatever you want here
Toast.makeText(...).show();
}
};
在同一活动的onCreate注册接收者：
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
...
LocalBroadcastManager.getInstance(this).registerReceiver(mNotificationReceiver, new IntentFilter("some_custom_id"));
}
不要忘记取消注册：
@Override
protected void onDestroy() {
LocalBroadcastManager.getInstance(this).unregisterReceiver(mNotificationReceiver);
super.onDestroy();
}
收到广播时，接收器内的代码将被执行。
现在，检查应用程序是否在前台，如果是，则发送广播。在IntentService：
@Override
protected void onHandleIntent(Intent intent) {
GeofencingEvent geofencingEvent = GeofencingEvent.fromIntent(intent);
if (geofencingEvent.hasError()) {
String errorMessage = getErrorString(this,
geofencingEvent.getErrorCode());
return;
}
int geofenceTransition = geofencingEvent.getGeofenceTransition();
// Test that the reported transition was of interest.
if (geofenceTransition == Geofence.GEOFENCE_TRANSITION_ENTER ||
geofenceTransition == Geofence.GEOFENCE_TRANSITION_EXIT) {
...
if(MyApplication.isActivityVisible()){
Intent intnt = new Intent("some_custom_id");
intnt.putExtra("message", geofenceTransitionDetails);
LocalBroadcastManager.getInstance(this).sendBroadcast(intnt);
}else{
sendNotification(geofenceTransitionDetails);
}
} else {
// Log the error.
}
}
重要的位是最后一个嵌套的if语句：
if(MyApplication.isActivityVisible()){
Intent intnt = new Intent("some_custom_id");
intnt.putExtra("message", geofenceTransitionDetails);
LocalBroadcastManager.getInstance(this).sendBroadcast(intnt);
}else{
sendNotification(geofenceTransitionDetails);
}
使用上面定义的MyApplication.isActivityVisible()检查应用是否位于前台，然后发送通知或发送广播。只需确保您的意图代码（即"some_custom_id"）与您的发件人和收件人匹配。
就是这样。如果应用程序位于前台（特别是MainActivity），我会执行一些代码。如果应用程序不在前台，我会发送通知。
答案 1 :(得分：1)
最简单的方法是使用LocalBroadcastManager或某些event bus。
因此，当转换发生时，您应该从IntentService发送本地广播，并在component X和您IntentService之间的某些Activity中抓住它。 Component X必须跟踪您Activity中的任何一个是否在前景中
Activity），请注意，在Android中，如果您的应用处于前台，则无法轻松跟踪（如果您有超过1项活动，则我认为您无法正确执行此操作），you can try。
答案 2 :(得分：0)
a）您可以通知您的服务活动的生命周期事件。
b）您可以将UI的当前状态保存在活动的静态字段中，并在显示通知之前从服务中进行检查。