What is Fragment ? And Start With HelloFragment

Hi guys!!

Today I am going to discuss about Fragment. Now it is available with new API open source library android-support v4 or v7 or v13.  android-support v13 is the recent api library.
So lets start to know about fragment the question is arises first what is Fragment?

What is Fragment in Android?

• A fragment is a class implementing a portion of an activity.
• A fragment represents a particular operation or interface running within a larger activity.
• Fragments must be embedded in activities; they cannot run independent of activities.
• Most fragments define their own layout of views that live within the activity�s view hierarchy.  
• A fragment has its own life-cycle, closely related to the life-cycle of its host activity. 
• A fragment can be a static part of an activity, instantiated automatically during the activity�s creation.
  
• Or, you can create, add, and remove fragments dynamically in an activity at run-time.
  

What is Life cycle of Fragment ?

Fragments have a few extra life cycle callbacks managing interaction with the activity:

onAttach(Activity) => Called when the fragment has been associated with the activity.

onCreateView(LayoutInflater, ViewGroup, Bundle) => Called to create the view hierarchy associated   

 with the fragment.

onActivityCreated(Bundle) => Called when the activity�s onCreate() method has returned.

onDestroyView() => Called when the view hierarchy associated with the fragment is being removed.

onDetach() => Called when the fragment is being disassociated from the activity.

  Fragment Implemented ?

Fragments were added to the Android API in Honeycomb, API 11.

The primary classes related to fragments are:

android.app.Fragment 

android.app.FragmentManager 

android.app.FragmentTransaction

 

The primary classes related to fragments are available in library package are:

android.support.v4.app.FragmentActivity

android.support.v4.app.Fragment

android.support.v4.app.FragmentManager

android.support.v4.app.FragmentTransaction

 

To use the Compatibility Package features, your activity must use android.support.v4.app. FragmentActivity as a base class, rather than android.app.Activity or one of its subclasses. 

 

Lets start the use of this fragment with Simple Hello Fragment. 

main.xml

hello_fragment.xml

HelloFragment

package com.sunil.fragment;

import com.sunil.fragment.R;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class HelloFragment extends Fragment{
 
 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {  
  View v = inflater.inflate(R.layout.hello_fragment_layout, null);
  return v;
 }
 
}

MainActivity.java

package com.sunil.fragment;

import com.sunil.fragment.R;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;

public class MainActivity extends FragmentActivity {
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}

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