- What is findViewById () method used for?
- What is the difference between onCreate () and onStart ()?
- What does onCreate method do in Android?
- How do you know if a fragment is destroyed?
- How do you know if a fragment is visible?
- How do you destroy an activity?
- What is the difference between onCreate and onCreateView?
- Is onDestroy always called?
- What is the use of setTag in Android?
- Which method is called when app is killed android?
- What is onSaveInstanceState?
- Is it possible activity without UI in Android?
- What does finish () do in Android?
- Is onCreate only called once?
- What is onResume?
- Which method is called when we call finish () in your onCreate () method?
- What is setContentView?
- How do I use Requestfocus on Android?
What is findViewById () method used for?
Safe code using binding objects findViewById is the source of many user-facing bugs in Android.
It’s easy to pass an id that’s not in the current layout — producing null and a crash.
And, since it doesn’t have any type-safety built in it’s easy to ship code that calls findViewById(R..
What is the difference between onCreate () and onStart ()?
onCreate() is called when the when the activity is first created. onStart() is called when the activity is becoming visible to the user.
What does onCreate method do in Android?
onCreate(Bundle) is where you initialize your activity. When Activity is started and application is not loaded, then both onCreate() methods will be called. But for subsequent starts of Activity , the onCreate() of application will not be called.
How do you know if a fragment is destroyed?
Since all fragments are destroyed if the activity is destroyed, a simple answer could be calling getActivity(). isDestroyed() returning true if the activity is destroyed, therefore the fragment is destroyed.
How do you know if a fragment is visible?
viewPager. getCurrentItem() to get index and find current visible fragment as per use. The most simplest sloution might be. In onCreate of your DF fragment store a boolean in preferences .
How do you destroy an activity?
9 Answers. You can also add android:noHistory=”true” to your Activity tag in AndroidManifest. xml . Yes, all you need to do is call finish() in any Activity you would like to close.
What is the difference between onCreate and onCreateView?
onCreate is called on initial creation of the fragment. You do your non graphical initializations here. It finishes even before the layout is inflated and the fragment is visible. onCreateView is called to inflate the layout of the fragment i.e graphical initialization usually takes place here.
Is onDestroy always called?
Android Activity onDestroy() is not always called and if called only part of the code is executed. onDestroy() is not always called. If called, only part of the code is executed.
What is the use of setTag in Android?
setTag(int, Object) would store the objects in a static map, where the values were strongly referenced. This means that if the object contains any references pointing back to the context, the context (which points to pretty much everything else) will leak.
Which method is called when app is killed android?
Also, if Android kills the Application process, all activities are terminated. … The onStop() method is used to save application data. These methods are guaranteed to be called before the activity is terminated. If the user switches back to application which has been terminated by the system, it is restarted.
What is onSaveInstanceState?
onSaveInstanceState method gets called typically before/after onStop() is called. This varies from Android version to version. In the older versions it used to get before onStop() . Inside this method, we save the important values in the Bundle in the form of key value pairs.
Is it possible activity without UI in Android?
The answer is yes it’s possible. Activities don’t have to have a UI. It’s mentioned in the documentation, e.g.: An activity is a single, focused thing that the user can do.
What does finish () do in Android?
finish() work in android. On Clicking the back button from the New Activity, the finish() method is called and the activity destroys and returns to the home screen.
Is onCreate only called once?
Once and only once when an activity is created, is the onCreate() function executed. i think that in Android , you cant write something like this : AClassThatExtendedAnActivity instance = new AClassThatExtendedAnActivity();
What is onResume?
onResume() is one of the methods called throughout the activity lifecycle. onResume() is the counterpart to onPause() which is called anytime an activity is hidden from view, e.g. if you start a new activity that hides it. onResume() is called when the activity that was hidden comes back to view on the screen.
Which method is called when we call finish () in your onCreate () method?
While opening an Activity, onCreate() method of that Activity gets called. Within this onCreate() method if we call finish() method then it will execute the whole onCreate() method first and then it will execute the lifecycle method onDestroy() and the Activity gets destroyed.
What is setContentView?
Actually setContentView() is a method part of android. app. Activity class. It helps to set our content or render our layout on the screen. Based on the value given by the user, views will be inflated and rendered after the measurement of the screen, root view, and its child views.
How do I use Requestfocus on Android?
Request focus is used to set automatically keypad function on edittext box so just after activity starts it will automatically select defined Requestfocus editText and open keypad so application user can directly insert data into editText box.