Single frame fragments − Single frame fragments are using for hand hold devices like mobiles, here we can show only one fragment as a view. These files will have layout for the defined fragments.įinally modify activity file to define the actual logic of replacing fragments based on your requirement.īasically fragments are divided as three stages as shown below. You can override any of the functions based on your requirements.Ĭorresponding to each fragment, you will need to create layout files in XML file. The Fragment class has above mentioned callback functions. Next based on number of fragments, create classes which will extend the Fragment class. For example let's we want to use two fragments to handle landscape and portrait modes of the device. This involves number of simple steps to create Fragments.įirst of all decide how many fragments you want to use in an activity. OnDestroy()onDestroy() called to do final clean up of the fragment's state but Not guaranteed to be called by the Android platform. OnDestroyView()Fragment view will destroy after call this method OnStop()Fragment going to be stopped by calling onStop() This is usually where you should commit any changes that should be persisted beyond the current user session. OnPause() The system calls this method as the first indication that the user is leaving the fragment. OnStart()The onStart() method is called once the fragment gets visible. In this method you can instantiate objects which require a Context object At this point, view can be accessed with the findViewById() method. Activity and fragment instance have been created as well as the view hierarchy of the activity. OnActivit圜reated()The onActivit圜reated() is called after the onCreateView() method when the host activity is created. You can return null if the fragment does not provide a UI. To draw a UI for your fragment, you must return a View component from this method that is the root of your fragment's layout. OnCreateView() The system calls this callback when it's time for the fragment to draw its user interface for the first time. You should initialize essential components of the fragment that you want to retain when the fragment is paused or stopped, then resumed. OnCreate() The system calls this method when creating the fragment. Typically you get in this method a reference to the activity which uses the fragment for further initialization work. OnAttach()The fragment instance is associated with an activity instance.The fragment and the activity is not fully initialized. Here is the list of methods which you can to override in your fragment class − This section briefs different stages of its life cycle. Fragment Life CycleĪndroid fragments have their own life cycle very similar to an android activity. However, on a handset-sized screen, there's not enough room for both fragments, so Activity A includes only the fragment for the list of articles, and when the user selects an article, it starts Activity B, which includes the second fragment to read the article. The application can embed two fragments in Activity A, when running on a tablet-sized device. Now we can have a single activity but each activity can comprise of multiple fragments which will have their own layout, events and complete life cycle.įollowing is a typical example of how two UI modules defined by fragments can be combined into one activity for a tablet design, but separated for a handset design. But with the introduction of fragment we got more flexibility and removed the limitation of having a single activity on the screen at a time. So we were not able to divide device screen and control different parts separately. Prior to fragment introduction, we had a limitation because we can show only a single activity on the screen at one given point in time. You create fragments by extending Fragment class and You can insert a fragment into your activity layout by declaring the fragment in the activity's layout file, as a element. You can combine multiple fragments in a single activity to build a multi-pane UI.Ī fragment can be used in multiple activities.įragment life cycle is closely related to the life cycle of its host activity which means when the activity is paused, all the fragments available in the activity will also be stopped.Ī fragment can implement a behaviour that has no user interface component.įragments were added to the Android API in Honeycomb version of Android which API version 11. You can add or remove fragments in an activity while the activity is running. It will not be wrong if we say, a fragment is a kind of sub-activity.įollowing are important points about fragment −Ī fragment has its own layout and its own behaviour with its own life cycle callbacks. A Fragment is a piece of an activity which enable more modular activity design.
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