Add fragment to activity
To create a Fragment, a class must inherit from Android. Fragment and then override the OnCreateView method. OnCreateView will be called by the hosting Activity when it is time to put the Fragment on the screen, and will return a View. A typical OnCreateView will create this View by inflating a layout file and then attaching it to a parent container.
The container's characteristics are important as Android will apply the layout parameters of the parent to the UI of the Fragment. The following example illustrates this:. The code above will inflate the view Resource. Declaratively — Fragments can be used declaratively within.
Programmatic usage via the FragmentManager class will be discussed later in this guide. The following snippet shows how to use the class attribute to declare a fragment :. This next snippet shows how to declare a fragment by using the android:name attribute to identify the Fragment class :. When the Activity is being created, Android will instantiate each Fragment specified in the layout file and insert the view that is created from OnCreateView in place of the Fragment element.
Fragments that are declaratively added to an Activity are static and will remain on the Activity until it is destroyed; it is not possible to dynamically replace or remove such a Fragment during the lifetime of the Activity to which it is attached. If neither of the previous two methods is used, then the Fragment will assume the ID of the container view.
Android does not allow for uppercase characters in package names; it will throw an exception when trying to inflate the view if a package name contains an uppercase character. However, Xamarin. Android is more forgiving, and will tolerate uppercase characters in the namespace.
For example, both of the following snippets will work with Xamarin. However, the second snippet will cause an android. InflateException to be thrown by a pure Java-based Android application.
Fragments have their own lifecycle that is somewhat independent of, but still affected by, the lifecycle of the hosting Activity. For example, when an Activity pauses, all of its associated Fragments are paused.
The following diagram outlines the lifecycle of the Fragment. The list below shows the flow of the various callbacks in the lifecycle of a Fragment as it is being created:. OnInflate — Called when the Fragment is being created as part of a view layout. This may be called immediately after the Fragment is created declaratively from an XML layout file.
The Fragment is not associated with its Activity yet, but the ActivityBundleand AttributeSet from the view hierarchy are passed in as parameters. This method is best used for parsing the AttributeSet and for saving the attributes that might be used later by the Fragment. OnAttach — Called after the Fragment is associated with the Activity.A transaction is a way to add, replace, or remove fragments.
Adding Fragments to Activities
It gives us an interface for interacting with fragments. In this fragment, we have given red colour. It adds a fragment frag1 to the fragment layout which has id f1.
Also, add this fragment to Backstack to maintain a record of added fragments. It replaces one fragement to another like fragment 2 is replaced with fragment which is already placed on the layout of id f1. This was a simple tutorial on how to adddelete and replace fragments in an Android Application.
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Fragment in Android(Add,Delete and Replace)
Keep writing. Please enter your comment! Please enter your name here. You have entered an incorrect email address! Most Popular. Google launches Android Studio 3. Read more. The price of the new For all Android Developers, Firebase is an important part of their development process. But in a nutshell what is Firebase? Think like Load more.A fragment is a reusable class implementing a portion of an activity.
A Fragment typically defines a part of a user interface. Fragments must be embedded in activities; they cannot run independently of activities. Within a fragment-oriented architecture, activities become navigational containers that are primarily responsible for navigation to other activities, presenting fragments and passing data.
Within a fragment-heavy app, we need to remember to organize our code according to architectural best practices. Inside of an app which uses fragments extensively, we need to keep in mind that the role of an activity shifts. Fragments are content controllers and contain most views, layouts, and event logic including:. To reiterate, in a fragment-based architecture, the activities are for navigation and the fragments are for views and logic. A fragment, like an activity, has an XML layout file and a Java class that represents the Fragment controller.
Think of them as a partial re-usable activity:. There are two ways to add a fragment to an activity: dynamically using Java and statically using XML. Before embedding a "support" fragment in an Activity make sure the Activity is changed to extend from FragmentActivity or AppCompatActivity which adds support for the fragment manager to all Android versions. Any activity using fragments should make sure to extend from FragmentActivity or AppCompatActivity :. To add the fragment staticallysimply embed the fragment in the activity's xml layout file:.
The second way is by adding the fragment dynamically in Java using the FragmentManager. The FragmentManager class and the FragmentTransaction class allow you to add, remove and replace fragments in the layout of your activity at runtime.
In this case, you want to add a "placeholder" container usually a FrameLayout to your activity where the fragment is inserted at runtime:. If the fragment should always be within the activity, use XML to statically add the fragment but in more complex cases be sure to use the Java-based approach. Fragment has many methods which can be overridden to plug into the lifecycle similar to an Activity :. The most common ones to override are onCreateView which is in almost every fragment to setup the inflated view, onCreate for any data initialization and onActivityCreated used for setting up things that can only take place once the Activity has been fully created.
Refer to this detailed lifecycle chart to view the lifecycle of a fragment more visually. Often we need to lookup or find a fragment instance within an activity layout file. There are a few methods for looking up an existing fragment instance:. If the fragment was statically embedded in the XML within an activity and given an android:id such as fragmentDemo then we can lookup this fragment by id by calling findFragmentById on the FragmentManager :.
If the fragment was dynamically added at runtime within an activity then we can lookup this fragment by tag by calling findFragmentByTag on the FragmentManager :. If the fragment was dynamically added at runtime within an activity into a ViewPager using a FragmentPagerAdapter then we can lookup the fragment by upgrading to a SmartFragmentStatePagerAdapter as described in the ViewPager guide. Now with the adapter in place, we can also easily access any fragments within the ViewPager using getRegisteredFragment :.
Note that the ViewPager loads the fragment instances lazily similar to the a ListView recycling items as they appear on screen. If you attempt to access a fragment that is not on screen, the lookup will return null. Fragments should generally only communicate with their direct parent activity.
Fragments communicate through their parent activity allowing the activity to manage the inputs and outputs of data from that fragment coordinating with other fragments or activities. Think of the Activity as the controller managing all interaction with each of the fragments contained within. A few exceptions to this are dialog fragments presented from within another fragment or nested child fragments.
Both of these cases are situations where a fragment has nested child fragments and that are therefore allowed to communicate upward to their parent which is a fragment. The important thing to keep in mind is that fragments should not directly communicate with each other and should generally only communicate with their parent activity.
Fragments should be modular, standalone and reusable components. The fragments allow their parent activity to respond to intents and callbacks in most cases. In certain cases, your fragment may want to accept certain arguments.
A common pattern is to create a static newInstance method for creating a Fragment with arguments. This is because a Fragment must have only a constructor with no arguments.The practical workbook for the Advanced Android Development course is now available as a series of Codelabs. Visit the course overview for more information. A Fragment is a self-contained component with its own user interface UI and lifecycle that can be reused in different parts of an app's UI.
A Fragment can also be used without a UI, in order to retain values across configuration changes, but this lesson does not cover that usage.
A Fragment can be a static part of the UI of an Activitywhich means that the Fragment remains on the screen during the entire lifecycle of the Activity. However, the UI of an Activity may be more effective if it adds or removes the Fragment dynamically while the Activity is running. One example of a dynamic Fragment is the DatePicker object, which is an instance of DialogFragmenta subclass of Fragment.
Dynamically add Fragments to an Activity in Android
The date picker displays a dialog window floating on top of its Activity window when a user taps a button or an action occurs.
The user can click OK or Cancel to close the Fragment. This practical introduces the Fragment class and shows you how to include a Fragment as a static part of a UI, as well as how to use Fragment transactions to add, replace, or remove a Fragment dynamically. The FragmentExample1 app shows an image and the title and text of a magazine article. It also shows a Fragment that enables users to provide feedback for the article.
In this case the feedback is very simple: just "Yes" or "No" to the question "Like the article? The Fragment is skeletal, but it demonstrates how to create a Fragment to use in multiple places in your app's UI. In the first task, you add the Fragment statically to the Activity layout so that it is displayed for the entire duration of the Activity lifecycle.
The user can interact with the radio buttons in the Fragment to choose either "Yes" or "No," as shown in the figure above. In the second task, in which you create the FragmentExample2 app, you add the Fragment dynamically — your code adds, replaces, and removes the Fragment while the Activity is running. You will change the Activity code and layout to do this.
As shown below, the user can tap the Open button to show the Fragment at the top of the screen. The user can then interact with the UI elements in the Fragment.
The user taps Close to close the Fragment. In this task you modify a starter app to add a Fragment statically as a part of the layout of the Activitywhich means that the Fragment is shown during the entire lifecycle of the Activity. This is a useful technique for consolidating a set of UI elements such as radio buttons and text and user interaction behavior that you can reuse in layouts for other activities.
Refactor and rename the project to FragmentExample1. For help with copying projects and refactoring and renaming, see Copy and rename a project.
Explore the app using Android Studio. Uncheck the Include fragment factory methods and Include interface callbacks options.
Click Finish to create the Fragment.
Create a fragment
All subclasses of Fragment must include a public no-argument constructor as shown. The Android framework often re-instantiates a Fragment object when needed, in particular during state restore. The framework needs to be able to find this constructor so it can instantiate the Fragment.
The Fragment class uses callback methods that are similar to Activity callback methods. In addition, the following string resources are also defined in the strings.
Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I want to add a Fragment to an Activity that implements its layout programmatically.
I looked over the Fragment documentation but there aren't many examples describing what I need. Here is the type of code I tried to write:. This code compiles but crashes at start, probably because my FragmentTransaction. What is the correct way to do this? It turns out there's more than one problem with that code. A fragment cannot be declared that way, inside the same java file as the activity but not as a public inner class.
The framework expects the fragment's constructor with no parameters to be public and visible.
Moving the fragment into the Activity as an inner class, or creating a new java file for the fragment fixes that. The second issue is that when you're adding a fragment this way, you must pass a reference to the fragment's containing view, and that view must have a custom id. Using the default id will crash the app.
Here's the updated code:. Here is what I came up with after reading Tony Wong's comment :. If you are using Kotlin make sure to take a look at what the Kotlin extensions by Google provide or just write your own. To add a fragment into a Activity or FramentActivity it requires a Container. That container should be a " Framelayout ", which can be included in xml or else you can use the default container for that like " android.
IMPORTANT: don't use replace fragment as most of the approach shown here, unless you don't mind to lose fragment variable instance state during onrecreation process. For API level 17 or higher, View. The utility method provides a unique id that is not used in build time.A Fragment represents a behavior or a portion of user interface in a FragmentActivity. You can combine multiple fragments in a single activity to build a multi-pane UI and reuse a fragment in multiple activities.
You can think of a fragment as a modular section of an activity, which has its own lifecycle, receives its own input events, and which you can add or remove while the activity is running sort of like a "sub activity" that you can reuse in different activities. A fragment must always be hosted in an activity and the fragment's lifecycle is directly affected by the host activity's lifecycle.
For example, when the activity is paused, so are all fragments in it, and when the activity is destroyed, so are all fragments.
However, while an activity is running it is in the resumed lifecycle stateyou can manipulate each fragment independently, such as add or remove them. When you perform such a fragment transaction, you can also add it to a back stack that's managed by the activity—each back stack entry in the activity is a record of the fragment transaction that occurred.
The back stack allows the user to reverse a fragment transaction navigate backwardsby pressing the Back button. When you add a fragment as a part of your activity layout, it lives in a ViewGroup inside the activity's view hierarchy and the fragment defines its own view layout. This document describes how to build your application to use fragments, including how fragments can maintain their state when added to the activity's back stack, share events with the activity and other fragments in the activity, contribute to the activity's app bar, and more.
For information about handling lifecycles, including guidance about best practices, see the following resources:. Android introduced fragments in Android 3. Because a tablet's screen is much larger than that of a handset, there's more room to combine and interchange UI components. Fragments allow such designs without the need for you to manage complex changes to the view hierarchy.
By dividing the layout of an activity into fragments, you become able to modify the activity's appearance at runtime and preserve those changes in a back stack that's managed by the activity.
They are now widely available through the fragment support library. For example, a news application can use one fragment to show a list of articles on the left and another fragment to display an article on the right—both fragments appear in one activity, side by side, and each fragment has its own set of lifecycle callback methods and handle their own user input events. Thus, instead of using one activity to select an article and another activity to read the article, the user can select an article and read it all within the same activity, as illustrated in the tablet layout in figure 1.
You should design each fragment as a modular and reusable activity component. That is, because each fragment defines its own layout and its own behavior with its own lifecycle callbacks, you can include one fragment in multiple activities, so you should design for reuse and avoid directly manipulating one fragment from another fragment. This is especially important because a modular fragment allows you to change your fragment combinations for different screen sizes.Most of developers used in this concept for client requirements.
Add fragment to a activity, it requires a one container to get the values. In that container access to be Framelayout with added to be XML or you can use the default container. Below i will show you how to add the fragment into an activity dynamically. You have must provide a layout for a fragment, to implement the onCreateView callback method.
Okay fine, now time to make android app in add fragment to activity xml.
The code is. You have to create another xml file. After creating xml file just add the following code. The code like.
Now you to move on the MainActivity. The complete code of MainActivity is. After making MainActivity. Now time to run your application in android emulator.
The exact output like below image. This is J. Blogging is my Passion, I love to write article about Programming.
Adding fragment to Activity in Android. Activity; import android. FragmentManager; import android. FragmentTransaction; import android. Bundle; import android. View; import android. OnClickListener; import android.
Activity. FragmentManager .