问题
I have two activities
MainActivityDeepLinkActivity
I set up everything to use the NavUtils for navigating up like advised here, here and here.
What I want to achieve is:
- Start
DeepLinkActivityvia a deep link - Press up
- Go to
MainActivity
Everything works nicely as long as there is any task of my app in the recent apps.
However, when I swipe away my app from the recent apps, it behaves like this:
- Swipe away my app from recent apps
- Start
DeepLinkActivityvia a deep link - Press up
- My app closes, like when pressing back
I debugged the code, and found out, that NavUtils.shouldUpRecreateTask() returns false.
upIntent has everything set to normal, like my Component set.
But still, NavUtils.navigateUpTo() behaves just like a call to finish().
No log statement, nothing.
Any ideas, how to fix that?
AndroidManifest.xml
<activity
android:name=".DeepLinkActivity"
android:parentActivityName="my.package.MainActivity">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="my.package.MainActivity"/>
<intent-filter>
<!-- Some intent filter -->
</intent-filter>
</activity>
DeepLinkActivity.java
@Override
public boolean onOptionsItemSelected(final MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
Intent upIntent = NavUtils.getParentActivityIntent(this);
if (NavUtils.shouldUpRecreateTask(this, upIntent)) {
// create new task
TaskStackBuilder.create(this).addNextIntentWithParentStack(upIntent)
.startActivities();
} else {
// Stay in same task
NavUtils.navigateUpTo(this, upIntent);
}
return true;
default:
return super.onOptionsItemSelected(item);
}
}
----- Edit -----
I realized that a few Google Apps are broken in the same way. If you jump e.g. to Contacts from search, press up in AB and you'll find yourself on the home screen instead of the contacts app. (API19/cm11)
回答1:
I think that method is bugged. I've read support library source code, and that method check for intent's action. It only works when your App was previously created..as you've described, if you kill it from Apps preview, shouldUp method stops working.
I've fixed this using my own "shouldUpRecreateTask". When I receive a Notification that creates directly an Activity (Like your behaviour), I send from my BroadCastReceiver a custom Action inside the intent. Then, in my Method I do the next thing:
private final boolean shouldUpRecreateTask(Activity from){
String action = from.getIntent().getAction();
return action != null && action.equals(com.xxxxxx.activities.Intent.FROM_NOTIFICATION);
}
..........................
if (shouldUpRecreateTask(this)) {
TaskStackBuilder.create(this)
.addNextIntentWithParentStack(upIntent)
.startActivities();
} else {
fillUpIntentWithExtras(upIntent);
NavUtils.navigateUpTo(this, upIntent);
}
回答2:
My solution to OPs problem:
public void navigateUp() {
final Intent upIntent = NavUtils.getParentActivityIntent(this);
if (NavUtils.shouldUpRecreateTask(this, upIntent) || isTaskRoot()) {
Log.v(logTag, "Recreate back stack");
TaskStackBuilder.create(this).addNextIntentWithParentStack(upIntent).startActivities();
} else {
NavUtils.navigateUpTo(this, upIntent);
}
}
isTaskRoot() will return true if DeepLinkActivity is the root of a task (initial launch of application or application was previously terminated through task manager). This way I'm not loosing existing back stack if activity was launched through link when applications task was already in the foreground.
回答3:
It looks like NavUtils.shouldUpRecreateTask(this, upIntent) is not prepared for this special case.
My current workaround is checking, if the Activity was deep linked and force a new task stack for cases like this.
In my case, I pass around objects in EXTRAs internally.
But an ACTION and Uri is set if the Activity is started from outside by following a link to a specific URL or by touching NFC aware devices.
@Override
public boolean onOptionsItemSelected(final MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
Intent upIntent = NavUtils.getParentActivityIntent(this);
if (NavUtils.shouldUpRecreateTask(this, upIntent)
|| getIntent().getAction() != null) { // deep linked: force new stack
// create new task
TaskStackBuilder.create(this).addNextIntentWithParentStack(upIntent)
.startActivities();
} else {
// Stay in same task
NavUtils.navigateUpTo(this, upIntent);
}
return true;
default:
return super.onOptionsItemSelected(item);
}
}
回答4:
Do you use an <activity-alias> as your MAIN / LAUNCHER? When I change the <activity-alias> to an <activity>, up navigation works correctly. For some odd reason, navigation does not work properly when aliases are involved.
There is also a weird UI glitch which indicates that the native ActivityManager has a bug. After navigating up to the app's main activity using navigateUpTo(), press the device's back key. The current app will perform the activity exit animation and then immediately afterwards, the next-most-recent app will also perform an activity exit animation. This happens even if you launched into the current app from Android's Home screen. If you clear all recent apps and try the nav-up-then-back steps again, a random (i.e. unexpected) app will be presented during the exit animation.
Other apps should never be presented in these cases. It seems as though the activity manager is not managing the history stack correctly.
The offending bug may be found within the following method which appears at the bottom of this diff:
+ public boolean navigateUpTo(IBinder token, Intent destIntent, int resultCode,
+ Intent resultData) {
+ ComponentName dest = destIntent.getComponent();
+
+ synchronized (this) {
+ ActivityRecord srec = ActivityRecord.forToken(token);
+ ArrayList<ActivityRecord> history = srec.stack.mHistory;
+ final int start = history.indexOf(srec);
+ if (start < 0) {
+ // Current activity is not in history stack; do nothing.
+ return false;
+ }
+ int finishTo = start - 1;
+ ActivityRecord parent = null;
+ boolean foundParentInTask = false;
+ if (dest != null) {
+ TaskRecord tr = srec.task;
+ for (int i = start - 1; i >= 0; i--) {
+ ActivityRecord r = history.get(i);
+ if (tr != r.task) {
+ // Couldn't find parent in the same task; stop at the one above this.
+ // (Root of current task; in-app "home" behavior)
+ // Always at least finish the current activity.
+ finishTo = Math.min(start - 1, i + 1);
+ parent = history.get(finishTo);
+ break;
+ } else if (r.info.packageName.equals(dest.getPackageName()) &&
+ r.info.name.equals(dest.getClassName())) {
+ finishTo = i;
+ parent = r;
+ foundParentInTask = true;
+ break;
+ }
+ }
+ }
+
+ if (mController != null) {
+ ActivityRecord next = mMainStack.topRunningActivityLocked(token, 0);
+ if (next != null) {
+ // ask watcher if this is allowed
+ boolean resumeOK = true;
+ try {
+ resumeOK = mController.activityResuming(next.packageName);
+ } catch (RemoteException e) {
+ mController = null;
+ }
+
+ if (!resumeOK) {
+ return false;
+ }
+ }
+ }
+ final long origId = Binder.clearCallingIdentity();
+ for (int i = start; i > finishTo; i--) {
+ ActivityRecord r = history.get(i);
+ mMainStack.requestFinishActivityLocked(r.appToken, resultCode, resultData,
+ "navigate-up");
+ // Only return the supplied result for the first activity finished
+ resultCode = Activity.RESULT_CANCELED;
+ resultData = null;
+ }
+
+ if (parent != null && foundParentInTask) {
+ final int parentLaunchMode = parent.info.launchMode;
+ final int destIntentFlags = destIntent.getFlags();
+ if (parentLaunchMode == ActivityInfo.LAUNCH_SINGLE_INSTANCE ||
+ parentLaunchMode == ActivityInfo.LAUNCH_SINGLE_TASK ||
+ parentLaunchMode == ActivityInfo.LAUNCH_SINGLE_TOP ||
+ (destIntentFlags & Intent.FLAG_ACTIVITY_CLEAR_TOP) != 0) {
+ parent.deliverNewIntentLocked(srec.app.uid, destIntent);
+ } else {
+ try {
+ ActivityInfo aInfo = AppGlobals.getPackageManager().getActivityInfo(
+ destIntent.getComponent(), 0, UserId.getCallingUserId());
+ int res = mMainStack.startActivityLocked(srec.app.thread, destIntent,
+ null, aInfo, parent.appToken, null,
+ 0, -1, parent.launchedFromUid, 0, null, true, null);
+ foundParentInTask = res == ActivityManager.START_SUCCESS;
+ } catch (RemoteException e) {
+ foundParentInTask = false;
+ }
+ mMainStack.requestFinishActivityLocked(parent.appToken, resultCode,
+ resultData, "navigate-up");
+ }
+ }
+ Binder.restoreCallingIdentity(origId);
+ return foundParentInTask;
+ }
+ }
回答5:
I found the following worked for me. If the Activity was deep linked from another activity or notification the stack would be created as you navigate up otherwise, the activities are just brought to the front.
case android.R.id.home:
Intent upIntent = NavUtils.getParentActivityIntent(this);
upIntent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(upIntent);
finish();
return true;
Provided you have
android:parentActivityName="parent.activity"
in your manifest
回答6:
It doesn't work for me too. So I handle up this way:
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == android.R.id.home) {
Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);
finish();
return true;
}
return super.onOptionsItemSelected(item);
}
My MainActivity is marked as singleTask in android manifest
android:launchMode="singleTask"
回答7:
If you go to your activity from a notification you'll have to create the stack when creating the notification, checkout this answer: NavUtils.shouldUpRecreateTask fails on JellyBean
回答8:
Try this :
@Override
public boolean onOptionsItemSelected(final MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
Intent upIntent = NavUtils.getParentActivityIntent(this);
if (NavUtils.shouldUpRecreateTask(this, upIntent)) {
// create new task
TaskStackBuilder.create(this).addNextIntentWithParentStack(upIntent)
.startActivities();
} else {
// Stay in same task
NavUtils.navigateUpTo(this, upIntent);
}
break;
default:
return super.onOptionsItemSelected(item);
}
return true;
}
回答9:
Try the following answer working for me in both case start activity from notification and start an activity from parent activity.
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
Intent upIntent = NavUtils.getParentActivityIntent(this);
if (NavUtils.shouldUpRecreateTask(this, upIntent) || isTaskRoot()) {
TaskStackBuilder.create(this).addNextIntentWithParentStack(upIntent)
.startActivities();
} else {
finish();
}
return true;
default:
return super.onOptionsItemSelected(item);
}
}
来源：https://stackoverflow.com/questions/19999619/navutils-navigateupto-does-not-start-any-activity