Android - Dynamicly Get the Current Activity in Fo

问题:

here is the situation:

1. In a Thread an event is triggered.
2. The current activity needs to be retrieved.
3. Then a Dialog Box is created on that activity and shown.

Problems: As far as I've searched there is no way to retrieve the current activity in the foreground.

Extra info: This needs to be able to be handled in multiple activities. So, it can be popped-up in Activity-A or B or C.

回答1:

I'm not sure if this is what you're looking for, but it seemed pretty straightforward. http://iamvijayakumar.blogspot.com/2011/09/get-current-activity-and-package-name.html

  ActivityManager am = (ActivityManager) this .getSystemService(ACTIVITY_SERVICE);
  List<RunningTaskInfo> taskInfo = am.getRunningTasks(1);
  ComponentName componentInfo = taskInfo.get(0).topActivity;
  Log.d(WebServiceHelper.TAG, "CURRENT Activity ::" + taskInfo.get(0).topActivity.getClassName()+"   Package Name :  "+componentInfo.getPackageName());

Hope this helps.

回答2:

Plan A: taking your request literally

Step #1: Have the thread be managed by a service

Step #2: have the service send a message when the "even is triggered" -- LocalBroadcastManager, Square's Otto, greenrobot's EventBus, etc.

Step #3: Have each activity be set up to listen for that message when it is in the foreground

Step #4: Have the activity display the dialog upon receipt of the message

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Plan B: same visual result

Step #1: Have the thread be managed by a service

Step #2: Have the service call startActivity() on a dialog-themed activity

Step #3: There is no step #3

回答3:

You can achieve this using a custom broadcast receiver. You can define a broadcast receiver in your thread and write the receiver in different activities. And from your thread you can decide which activity to send broadcast.

In the receiver, you can show the dialog.

回答4:

You may do that by extending Activity and Application and having methods that get and set the current viewed Activity reference as an Application level variable. Try this approach: How to get current foreground activity context in android?.

回答5:

Use Face book's stetho package is safest and simplest way for me (and no complaints from other team members that "it's hacky we won't approve!" thing...

Just as simple as:

ActivityTracker.get().tryGetTopActivity();