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What is the Fragment Life Cycle in Android?

A fragment can have many different lifecycles. In Android, they include the onCreate method, which ensures that the fragment’s root view is not null, and the onActivityCreate method, which is called when the host activity completes its onCreate() method. The onStart method displays the fragment while the fragment is in use, and the onPause method causes it to bear a similar state until it is replaced. After all the views are displayed, the fragment can be resumed by calling the onResume() method. In Android, onPause() causes the fragment to be unloaded, and onStart() calls the activity’s onStart() method. Finally, the onDetach method is called when the fragment is not in use or connected to the activity.

The onCreate() method receives a Bundle from the fragment’s parent activity. It also receives the state it saved during the onSaveInstanceState() method, and uses it to create the fragment view. Upon completion, the fragment is removed from the parent activity’s fragment manager. If you’re writing code for fragments, it is important to be aware of the fragment lifecycle.

What is the Fragment in Android?

Android uses a fragment life cycle to manage fragments, which are modular sections of an activity. This helps developers create flexible UI designs while optimizing user experience. A fragment’s life cycle is closely tied to that of its host activity. Fragments are also referred to as sub-activities. Listed below are the main functions of a fragment. This article will provide a high-level overview of the fragment life cycle.

The Fragment life cycle starts with the creation of a fragment. The fragment needs a view hierarchy to function, and Android calls the onCreateView() method to create a new view hierarchy. Once the View hierarchy is created, you need to initialize the Fragment’s members. Android will handle the rest. Inside the onCreateView() method, you must assign the Fragment members that hold references to the new view hierarchy.

The fragment life cycle starts with the onCreate stage, which occurs after the fragment attaches to the parent activity’s fragment manager. This stage allows the fragment to retrieve saved instance state data. The fragment will then inflate its user interface layout in the onCreateView() method. Finally, it will detach from the parent activity fragment manager during the onDestroy stage. In Android, the fragment life cycle is designed to handle state changes and prevent app crashes. During this life cycle, a fragment’s UI can be visible, but it cannot be used by the user.

What is a Life Cycle in Android?

The fragment life cycle consists of several stages that are called onCreate() and onDestroyView(). OnCreate() is called when the fragment is first visible to the user. This occurs after the activity onActivityCreated() or onStart() method has been completed. The fragment’s onStart() method performs the same function as the activity’s onStart() method. The fragment onDetach() method is called when the fragment has been detached from its parent activity.

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The fragment life cycle is complicated. A fragment may be part of many different activities and can even span multiple windows. However, it is important to understand that the fragment life cycle is highly complex and can’t be emphasized enough. If you’re developing an app for Android, you should be aware of this life cycle. Here’s a basic overview:

OnCreate(): This method initializes the fragment. It may return a null value, if it doesn’t have any UI, which means it can’t interact with the parent activity. OnStart(): This method displays the fragment, while onPause() re-creates the fragment’s state. After a fragment is replaced, it resumes its life cycle by calling the onResume method. It can also be called when the fragment is stopped. Finally, onDetach(): The fragment processes are removed.

What is Fragment with Example in Android?

What is Fragment in Android? Fragments are the modular sections of an activity. Each fragment has its own lifecycle and its own input events. A fragment can be added to a running activity or removed from it, reusing it in different activities. It can be extended by adding a Support Library to make it compatible with older versions of Android. A fragment can also be composed of multiple fragments.

When creating a fragment, you should always consider how it will fit into your app. You should not directly communicate with another fragment, but instead, use the host activity’s interface. You can do this by defining the fragment as an inner type, which requires the host activity to implement the interface. This way, the fragment will not know the details of the host activity. In the onAttach() method of the host activity, you can check if the fragment implements the interface. You can then implement a fragment that receives value from the onActivityCreated method of the host activity.

The lifecycle of a fragment is similar to that of an activity. Like an activity, it has two methods: onCreateView() and onActivityCreated(). The first method will be called when the fragment is created, and it will need to inflate its view before it can be used in the app. The second method will be called when the fragment is attached to the activity.

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What is the Fragment Life Cycle?

The fragment life cycle is a series of events that must occur before the fragment can be destroyed. OnCreate() is the first stage of the fragment’s life cycle. This method ensures that the fragment’s root view is non-null and is ready to display. OnActivityCreated() and onStart() are the next stages of the fragment life cycle. These methods are called when the host activity has completed its onCreate() method.

The onCreateView() method is called when a new View hierarchy is required. However, the user must initialize the View hierarchy. This method should not be called during the onCreateView() method because this will result in the fragment’s state being overwritten. This is a significant bug and should be avoided. Instead, call onSaveInstanceState(Bundle) before onCreateView() to avoid state corruption.

The fragment cleanup method is called when the fragment is no longer visible or interactive. This method forces any committed transactions to be applied to the fragment. Fragments should not communicate with each other and should only talk to their parent activity. When designing your fragments, you should always keep this in mind. After all, this way you can avoid any unnecessary clutter. For example, if you’re using a custom view, you should use a reusable, modular fragment.

What are Fragments Lifecycle States?

Fragments are lifecycled from start to end. These stages are called OnPause, OnStop, and OnDestroy. OnPause indicates the fragment will not allow user interaction and OnStop detaches the fragment view from the window. OnStop is called when the fragment is no longer visible and OnDestroy is called when the fragment has reached its lifecycle state. It also performs resource release and stores state information.

When a fragment is attached to a parent activity, it calls the onCreate stage. At this stage, it can retrieve saved instance state data. OnCreateView() invokes the onViewStateRestored() callback to set the fragment’s state and interact with the layout. It can also receive user input from the onCreateView() callback. OnCreateView() is also a lifecycle stage.

Fragments also receive callbacks when the user selects an item in a context menu. This is known as the on-item-selected callback, and the fragment gets the same callback as the activity when the user selects a menu item. The fragment’s activity receives on-item-selected callsbacks when a menu item is selected. Similarly, when a user touches an item in a context menu, the fragment receives on-item-selected callbacks, and so does the activity.

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Why Fragments are Used in Android?

In Android, fragments are components that contain activities. A fragment in an activity will most likely require communication with the parent activity. This is to be avoided. Android supports fragments for both smartphones and tablets. The fragment may implement more than one interface. The following example shows how to use fragments. The fragment must implement at least one interface. The fragment must be a type that the host activity implements. If the host activity does not implement the interface, the fragment will not receive the data that it needs.

A fragment can be managed by defining callback methods. The onCreate method ensures that the root view of the fragment is not null. The onStart method is called after the host activity completes the onCreate() method. The onStart() method is called when the fragment is ready to display content. The onResume and onPause methods are used to allocate resources and clean up fragment state. The onDestroy method is called when the fragment is no longer associated with the activity.

What is Difference Between Activity And Fragment?

While fragments and activities have similar functions, the primary difference between the two is their lifecycle. Fragments are lite weight, and their own lifecycle is parallel to that of an Activity. Fragments have their own set of callback methods, and they are also more flexible than activities. This article explains the differences between fragments and activities and how each is used in a mobile application.

While an activity is an application’s navigational container, a fragment is a reusable, smaller piece of an app. Each fragment encapsulates a different piece of UI, and must be embedded within its parent activity. Fragments can be reused many times within an app and across devices, but an Activity remains the primary UI container. A fragment manager manages each fragment.

While activities are primarily used for navigation, fragments are used for logic and views. They have their own Java classes and XML layout files. Fragments can be added statically or dynamically. In addition, Java users will need to change the path of the FooFragment if the fragment is added dynamically. Fragments that are dynamically added will be replaced by a FragmentTransaction.

Learn More Here:

1.) Android Help Center

2.) Android – Wikipedia

3.) Android Versions

4.) Android Guides