What Are Fragments In Android Development?

Table of contents

• Why Use Fragments?
• How to Create a Fragment
• Adding a Fragment to an Activity
• Replacing a Fragment
• Removing a Fragment
• Conclusion

A fragment is a small part of an Android app's user interface (UI). Think of it like a mini activity, thus if you know what an Android Activity [→] is. It has its own layout and behavior. But, it cannot live on its own. It must be part of an activity.

Why Use Fragments?

Fragments help us in many ways:

1. Modular UI: You can break down your UI into smaller parts. This makes it easier to manage.
2. Reusable UI: You can use the same fragment in different activities. This saves time and effort.
3. Dynamic UI: You can change fragments at runtime. This makes your app more flexible.

How to Create a Fragment

Creating a fragment is easy. Follow these steps:

1. Create a Java Class: This class will extend the Fragment class.
2. Override onCreateView Method: This method sets up the layout for the fragment.

Here is a simple example:

✅ Wrap📋
01: public class ExampleFragment extends Fragment {
02:     @Override
03:     public View onCreateView(LayoutInflater inflater, ViewGroup container,
04:                              Bundle savedInstanceState) {
05:         return inflater.inflate(R.layout.fragment_example, container, false);
06:     }
07: }

In this code:

• ExampleFragment is the name of our fragment.
• onCreateView method sets up the UI using a layout file called fragment_example.xml.

Adding a Fragment to an Activity

To add a fragment to an activity, you need to do the following:

1. Add a Container to the Activity Layout: This is where the fragment will go.

✅ Wrap📋
01: <FrameLayout
02:     android:id="@+id/fragment_container"
03:     android:layout_width="match_parent"
04:     android:layout_height="match_parent" />

2. Add the Fragment in the Activity's Code:

✅ Wrap📋
01: FragmentManager fragmentManager = getSupportFragmentManager();
02: FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
03: ExampleFragment fragment = new ExampleFragment();
04: fragmentTransaction.add(R.id.fragment_container, fragment);
05: fragmentTransaction.commit();

In this code:

• fragmentManager helps us manage fragments.
• fragmentTransaction helps us add, replace, or remove fragments.
• fragment_container is the ID of the container in the activity layout.

Replacing a Fragment

You can replace a fragment with another fragment. This is useful for dynamic UIs. Here is how you do it:

✅ Wrap📋
01: AnotherFragment anotherFragment = new AnotherFragment();
02: fragmentTransaction.replace(R.id.fragment_container, anotherFragment);
03: fragmentTransaction.commit();

In this code:

• AnotherFragment is a different fragment we want to show.

Removing a Fragment

If you want to remove a fragment, you can do this:

✅ Wrap📋
01: fragmentTransaction.remove(fragment);
02: fragmentTransaction.commit();

Conclusion

In summary Fragments make it possible to create reusable UI components.

Here is another article you might like 😊 What Is An Activity In Android Development?