Calling startActivity() from outside of an Activity?

Question

I'm using an AlarmManager to trigger an intent that broadcasts a signal. The following is my code:

AlarmManager mgr = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent i = new Intent(this, Wakeup.class);
try
{
    PendingIntent pi = PendingIntent.getBroadcast(this, 0, i, 0);
    Long elapsed +=  // sleep time;
    mgr.set(AlarmManager.RTC_WAKEUP, elapsed, pi);
}
catch(Exception r)
{
    Log.v(TAG, "RunTimeException: " + r);
}

I'm calling this code from an Activity, so I don't know how I could be getting the following error...

ERROR/AndroidRuntime(7557): java.lang.RuntimeException: Unable to start receiver com.wcc.Wakeup: android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity  context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?

score 524 · Answer 1 · edited Jan 05 '19 at 10:44

524

if your android version is below Android - 6 then you need to add this line otherwise it will work above Android - 6.

...
Intent i = new Intent(this, Wakeup.class);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
...

edited Jan 05 '19 at 10:44

VIISHRUT MAVANII

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answered Sep 11 '10 at 05:21

Cristian

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yes this works. but if you want to start multiple instances of the same Activity this does not work. Since the FLAG_ACTIVITY_NEW_TASK will resume the same existing Activity – Ovidiu Latcu Sep 30 '11 at 13:16
7

Add flag FLAG_ACTIVITY_Multiple_TASKS TO RESOLVE YOUR problem – Pavankumar Vijapur Dec 09 '11 at 07:50
1

Beware, you need this on Android 9+ also, see [this answer](https://stackoverflow.com/a/50833599/1000551) for clarifications – Vadim Kotov Jan 22 '20 at 09:15

score 59 · Answer 2 · edited Dec 30 '14 at 17:37

59

For Multiple Instance of the same activity , use the following snippet,

Note : This snippet, I am using outside of my Activity. Make sure your AndroidManifest file doesn't contain android:launchMode="singleTop|singleInstance". if needed, you can change it to android:launchMode="standard".

Intent i = new Intent().setClass(mActivity.getApplication(), TestUserProfileScreenActivity.class);  
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_MULTIPLE_TASK);

// Launch the new activity and add the additional flags to the intent
mActivity.getApplication().startActivity(i);

This works fine for me. Hope, this saves times for someone. If anybody finds a better way, please share with us.

edited Dec 30 '14 at 17:37

L93

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answered Mar 10 '12 at 11:15

Nandagopal T

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5

Please understand the difference between setFlags() and addFlag() methods. All you are doing now is launching an activity with FLAG_ACTIVITY_NEW_TASK. As in the code posted by Cristian below. – Pinser Mar 21 '12 at 05:18
1

-------------------------------------------------------------------i.addFlag(Intent.FLAG_ACTIVITY_MULTIPLE_TASK); i.addFlag(Intent.FLAG_ACTIVITY_NEW_TASK); ------------------------------------------------------------------- i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_MULTIPLE_TASK); – Pinser Mar 21 '12 at 05:22

Hrishikesh Kadam · Answer 3 · 2019-08-11T22:10:13.750

Android Doc says -

FLAG_ACTIVITY_NEW_TASK requirement is now enforced

With Android 9, you cannot start an activity from a non-activity context unless you pass the intent flag FLAG_ACTIVITY_NEW_TASK. If you attempt to start an activity without passing this flag, the activity does not start, and the system prints a message to the log.

Note: The flag requirement has always been the intended behavior, and was enforced on versions lower than Android 7.0 (API level 24). A bug in Android 7.0 prevented the flag requirement from being enforced.

That means for (Build.VERSION.SDK_INT <= Build.VERSION_CODES.M) || (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) it is mandatory to add Intent.FLAG_ACTIVITY_NEW_TASK while calling startActivity() from outside of an Activity context.

So it is better to add flag for all the versions -

...
Intent i = new Intent(this, Wakeup.class);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
...

score 15 · Answer 4 · answered May 29 '12 at 08:43

15

You didn't paste the part where you call startActivity, that's the interesting part.

You might be calling startActivity in a Service context, or in an Application context.

Print "this" to log cat before making the startActivity call, and see what it refers to, it's sometimes a case of using an inner "this" accidentally.

answered May 29 '12 at 08:43

marmor

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1

This is likely the problem OP is having. I have encountered the same. Launching an activity with getApplicationContext() instead of an existing activity will trigger this error. – Hazen Hills Software Mar 01 '14 at 00:26
NICE :) I'm quite sure this was the mistake I try to spot the whole evening. Thanks, Mister. – Martin Pfeffer Sep 16 '14 at 02:49

score 9 · Answer 5 · answered Jul 28 '17 at 20:04

Sometimes this error can occur without an explicit call to startActivity(...). For example, some of you may have seen a stack trace like this in Crashlytics:

Fatal Exception: android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity  context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?
       at android.app.ContextImpl.startActivity(ContextImpl.java:1597)
       at android.app.ContextImpl.startActivity(ContextImpl.java:1584)
       at android.content.ContextWrapper.startActivity(ContextWrapper.java:337)
       at android.text.style.URLSpan.onClick(URLSpan.java:62)
       at android.text.method.LinkMovementMethod.onTouchEvent(LinkMovementMethod.java:217)
       at android.widget.TextView.onTouchEvent(TextView.java:9522)
       at android.view.View.dispatchTouchEvent(View.java:8968)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at android.widget.AbsListView.dispatchTouchEvent(AbsListView.java:5303)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
       at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
       at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2559)
       at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1767)
       at android.app.Activity.dispatchTouchEvent(Activity.java:2866)
       at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:67)
       at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:67)
       at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2520)
       at android.view.View.dispatchPointerEvent(View.java:9173)
       at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4706)
       at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4544)
       at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4068)
       at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4121)
       at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4087)
       at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4201)
       at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4095)
       at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4258)
       at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4068)
       at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4121)
       at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4087)
       at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4095)
       at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4068)
       at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:6564)
       at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:6454)
       at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:6425)
       at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:6654)
       at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185)
       at android.os.MessageQueue.nativePollOnce(MessageQueue.java)
       at android.os.MessageQueue.next(MessageQueue.java:143)
       at android.os.Looper.loop(Looper.java:130)
       at android.app.ActivityThread.main(ActivityThread.java:5942)
       at java.lang.reflect.Method.invoke(Method.java)
       at java.lang.reflect.Method.invoke(Method.java:372)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)

And you may wonder what you did wrong, since the trace only includes framework code. Well, here's an example of how this can happen. Let's say we're in a fragment.

Activity activity = getActivity();
Context activityContext = activity;
Context appContext = activityContext.getApplicationContext();
LayoutInflater inflater = LayoutInflater.from(appContext); // whoops!
View view = inflater.inflate(R.layout.some_layout, parent, false);
TextView tvWithLinks = (TextView) view.findViewById(R.id.tv_with_links);

tvWithLinks.setMovementMethod(LinkMovementMethod.getInstance()); // whoops!!

Now, when a user clicks on that text view, your app will crash with the stack trace above. This is because the layout inflater has a reference to the application context, and so therefore your text view has an application context. Clicking on that text view implicitly calls appContext.startActivity(...).

Final note: I tested this on Android 4, 5, 6, and 7 devices. It only affects 4, 5, and 6. Android 7 devices apparently have no trouble calling appContext.startActivity(...).

I hope this helps someone else!

score 1 · Answer 6 · edited Mar 21 '13 at 12:19

1

Try changing to this line:

PendingIntent pendingIntent = PendingIntent.getBroadcast(getContext(), 0, i, 0);

edited Mar 21 '13 at 12:19

Michael Celey

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answered Mar 20 '13 at 16:56

Luís Ledebour

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score 1 · Answer 7 · answered Jun 15 '19 at 07:31

I just want to notice that startActivity from outside an activity is valid in some android versions (between N and O-MR1) and the interesting point is that it is a bug in android source code!

This is the comment above startActivity implementation. See here.

Calling start activity from outside an activity without FLAG_ACTIVITY_NEW_TASK is generally not allowed, except if the caller specifies the task id the activity should be launched in. A bug was existed between N and O-MR1 which allowed this to work.

what is the solution for that – Malavan Jan 15 '20 at 16:55 — Malavan, Jan 15 '20 at 16:55

score 1 · Answer 8 · answered Mar 17 '20 at 10:40

This same error I have faced in case of getting Notification in latest Android devices 9 and 10.

It depends on Launch mode how you are handling it. Use below code:- android:launchMode="singleTask"

Add this flag with Intent:- intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

score 1 · Answer 9 · answered Jan 08 '21 at 11:29

1

In my case I have used context for startActivity, after changing that with ActivityName.this . it solves. I'm using method from util class so this happens.

Hope it help some one.

answered Jan 08 '21 at 11:29

Dharmishtha

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Md. Shafiqur Rahman · Answer 10 · 2017-03-07T04:32:24.553

0

When you want to open an activity within your app then you can call the startActivity() method with an Intent as parameter. That intent would be the activity that you want to open. First you have to create an object of that intent with first parameter to be the context and second parameter to be the targeted activity class.

Intent intent = new Intent(this, Activity_a.class);
startActivity(intent);

Hope this will help.

edited Mar 07 '17 at 04:32

answered Mar 05 '17 at 11:48

Md. Shafiqur Rahman

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I'm writing as a reviewer because your answer has been flagged for low-quality. The shortcoming of this answer is that there's no explanation of what your code does or of why it solves the problem posed in the question. Would you please add some explanatory comments, bearing in mind that many programmers could read your answer in future for guidance. Thank you! – Bill Bell Mar 05 '17 at 17:58
When you wnat to open an activity within your app then you can call the startActivity() method with an Intent as parameter. That intent would be the activity that you want to open. First you have to create an object of that intent with first parameter to be the context and second parameter to be the targeted activity class. Hope this will help. – Md. Shafiqur Rahman Mar 06 '17 at 10:59
OK. But rather than putting that information in a comment you should edit your answer and put it there. I regret belabouring this point but it's important to do this for every answer. Best regards. – Bill Bell Mar 06 '17 at 14:32
Yes, please include explanations as to why your answer is correct. We only learn to be better programmers when we learn WHY we do the things we do. – kiwicomb123 Jul 24 '17 at 00:49

score 0 · Answer 11 · answered Jul 26 '22 at 06:07

Here's the code. I have implemented it in a wallpaper api implementation app. In my app specifically when user click on a wallpaper image it will revert it on full screen view.

holder.imageView.setOnClickListener {
          val i = Intent(context,FullScreenWallpaper::class.java)
          i.putExtra("raheel", wallpaperModelList2[position])
          i.flags = Intent.FLAG_ACTIVITY_NEW_TASK
          context.startActivity(i)
      }

Calling startActivity() from outside of an Activity?

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