Develop Reference

Can I limit findViewById() to within the scope of an individual fragment?

In my application, I have multiple instances of the same fragment, Activity_Fragment, displayed in a LinearLayout. In each fragment, there is an activity_text textview and an edit_button. When the button is pressed in a fragment, it should change the text of the textview in the same fragment. However, when multiple instances of the fragment are added, any edit_button pressed in any fragment will only change the activity_text textview in the first fragment added to the LinearLayout. This is because all fragments are identical, and their child views share the same id's. Each fragment should act independently of one other; any edit_button pressed in a fragment should only affect that fragment.
Is it possible to have the findViewById() method limited to the scope of an individual fragment so that one fragment won't be affected by an event in another fragment, or will I have to somehow change the id of each view in a fragment upon creation?
Here is the Activity Fragment xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/activity_fragment">
<CheckBox
android:id="#+id/checkbox"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="32dp"
android:layout_marginTop="16dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/activity_text"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginEnd="5dp"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:text="Edit Activity"
android:textSize="18sp"
app:layout_constraintBaseline_toBaselineOf="#+id/checkbox"
app:layout_constraintLeft_toRightOf="#+id/checkbox"
app:layout_constraintRight_toLeftOf="#+id/edit_button"/>
<Button
android:id="#+id/edit_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="16dp"
android:layout_marginEnd="16dp"
android:layout_marginTop="16dp"
android:onClick="editActivity"
android:text="Edit Activity"
app:layout_constraintBaseline_toBaselineOf="#+id/checkbox"
app:layout_constraintRight_toRightOf="parent"/>
Here is my MainActivity.java with the ActivityFragment class. The onClick method for the edit_button is at the very bottom:
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public static class ActivityFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup
container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.activity_fragment, container,
false);
}
}
public void addActivity(View view) {
ActivityFragment fragment1 = new ActivityFragment();
getSupportFragmentManager().beginTransaction()
.add(R.id.fragment_container, fragment1).commit();
}
//This is the editButton method
public void editActivity(View view) {
TextView activityText = (TextView) findViewById(R.id.activity_text);
activityText.setText("success");
}
}

Your problem can be solved by limiting the scope that findViewById() scans. If you want to look within a particular fragment, you'll probably want to call myFragment.getView().findViewById() (rather than just using findViewById() from your activity).
So how can you do this? Well, it's not easy with the way you have things set up. Since you're using the android:onClick attribute to set your click listener, you have to handle things from inside the activity.
So don't use android:onClick.
Instead, inside your Fragment's onCreateView() method, write something like this:
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.your_fragment, container, false);
Button button = (Button) root.findViewById(R.id.edit_button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
TextView activityText = (TextView) getView().findViewById(R.id.activity_text);
activityText.setText("success");
}
});
return root;
}

you can use view.findViewById(R.id.activity_text) instead of the method from the activity.

Android Textview doesn't show text in a Fragment

I'm trying to add a Fragment to my FrameLayout, it seems that it is added correctly, but then i can't see the text of the TextView.
Fragment Layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
>
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/text1"
android:text="Hello"
android:background="#34f5d6"/>
</LinearLayout>
The FragmentClass:
import android.app.Fragment;
import android.content.Context;
import android.graphics.Color;
import android.os.Bundle;
import android.text.method.CharacterPickerDialog;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
public class TimerClass extends Fragment {
public static Fragment newInstance(Context context) {
TimerClass fragment = new TimerClass();
return fragment;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstance){
ViewGroup root=(ViewGroup)inflater.inflate(R.layout.mylayout,container,false);
return root;
}
}
And the code i use to add the fragment to the FrameLayout
FragmentTransaction tx= getFragmentManager().beginTransaction();
Fragment fragment= TimerClass.newInstance(getApplicationContext());
tx.replace(R.id.fl, fragment);
tx.commit();
I don't undestand why it doesn't show the text, I tryed to change the color of the text but it doesn't work.
If I change the background of the TextView, it works; also if I add an OnClockListener on the TextView, it works. Only it doesn't show the text.
Can you help me?
EDIT:
I found the solution: the problem was with the FrameLayout; it's top part was covered by the action bar.
By fixing the layout of the FrameLayout the problem disappeared.

First simply change this
ViewGroup root=(ViewGroup)inflater.inflate(R.layout.mylayout,container,false);
return root;
to
View root = inflater.inflate(R.layout.mylayout,container,false);
return root;
Also this one
public static Fragment newInstance(Context context) {
TimerClass fragment = new TimerClass();
return fragment;
}
to
public static TimerClass getInstance() {
TimerClass fragment = new TimerClass();
return fragment;
}

I think issue is only with height and width of your TextView because you have sated them as match_parent
so try to replace
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/text1"
android:text="Hello"
android:background="#34f5d6"/>
with
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/text1"
android:text="Hello"
android:background="#34f5d6"/>

How to switch between fragments during onclick?

I have a project I'm trying to do. I ran into a little issue and I'm not sure how to get around it. Below is an image of the application so far.
What I would like it to do is when the user onclicks one of the list items, the part which says "Hello! It's Fragment2" changes to a new xml which I declared in the app. So if I click the ATO listItem, then the fragment on the right side should change to something like "Hello! It's ATO Fragment"
Here is my code so far:
AndroidListFragmentActivity:
package com.exercise.AndroidListFragment;
import android.app.Activity;
import android.os.Bundle;
public class AndroidListFragmentActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
Fragment2:
package com.exercise.AndroidListFragment;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Fragment2 extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// TODO Auto-generated method stub
return inflater.inflate(R.layout.fragment2, container, false);
}
}
MyListFragment1:
package com.exercise.AndroidListFragment;
import android.app.ListFragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class MyListFragment1 extends ListFragment {
String[] options ={
"ATO",
"BETA",
"DELT",
"PHI DELT",
"SAE",
"SIG NU",
"FIJI",
"SIG CHI",
"PHI PSI"
};
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ListAdapter myListAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, options);
setListAdapter(myListAdapter);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.listfragment1, container, false);
}
#Override
public void onListItemClick(ListView l, View v, int position, long id) {
// TODO Auto-generated method stub
Toast.makeText(getActivity(), getListView().getItemAtPosition(position).toString(), Toast.LENGTH_LONG).show();
}
}
Fragment2.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/fragment2text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Hello! It's Fragment2" />
</LinearLayout>
listfragment1.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="8dp"
android:paddingRight="8dp">
<ListView android:id="#id/android:list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:drawSelectorOnTop="false"/>
<TextView android:id="#id/android:empty"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="No data"/>
</LinearLayout>
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >
<fragment
android:name="com.exercise.AndroidListFragment.MyListFragment1"
android:id="#+id/fragment1"
android:layout_weight="1"
android:layout_width="0px"
android:layout_height="match_parent" />
<fragment
android:name="com.exercise.AndroidListFragment.Fragment2"
android:id="#+id/fragment2"
android:layout_weight="2"
android:layout_width="0px"
android:layout_height="match_parent" />
</LinearLayout>

Not sure what's the minimal fix to get your code working, but have you looked at using a Navigation Drawer to switch between the fragments? It looks to me like the example in the official docs matches pretty much exactly what you want to achieve.
A key is to have some kind of container for the currently displayed fragment (instead of using <fragment> like in your XML). For example:
<FrameLayout
android:id="#+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent" />
Then, switching fragments goes something like this:
Fragment fragment = new Fragment2();
// Insert the fragment by replacing any existing fragment
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.content_frame, fragment)
.commit();
Further reading: Add a Fragment to an Activity at Runtime in Android developer docs.

private void openFragment (int number) {
Fragment fragment = new Fragment();
switch (number) {
case FRAGMENT_1:
fragment = new *Fragment1*();
break;
case FRAGMENT_2:
fragment = new *Fragment2*();
break;
}
getSupportFragmentManager().beginTransaction()
.replace(R.id.fragment_frame, fragment)
.commit();
}

Fragment is not covering entire screen

please help
When I run my ListFragment actitivy and click on a fragment (either Buick or Mazda), the layout of the fragment I clicked on is supposed to replace and cover the entire screen but the
container containing the list of cars stays on the screen and my fragment layout is shown below it. How can I make my fragment's layout replace the entire screen?
I couldn't post my AVD image showing the screen because I don't have enough reputatons to do
but the screen was showing as below when I clicked on the first item on the list.
Buick
Mazda
Hello! It's a Buick
my Mainactivity
package in.cars.demo;
import android.app.Activity;
import android.os.Bundle;
public class CarsMainActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
My ListFragment activity
package in.cars.demo;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.app.ListFragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class CarsList extends ListFragment {
String[] cars = new String[] { "Buick", "Mazda" };
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ListAdapter myListAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, cars);
setListAdapter(myListAdapter);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.cars_container, container, false);
}
#Override
public void onListItemClick(ListView l, View v, int position, long id) {
Toast.makeText(getActivity(), getListView().getItemAtPosition(position).toString(), Toast.LENGTH_LONG).show();
switch (position) {
case 0:
Fragment fragment1 = new Fragment1();
FragmentTransaction transaction1 = getFragmentManager().beginTransaction();
transaction1.replace(R.id.car_fragment, fragment1);
transaction1.addToBackStack(null);
transaction1.commit();
break;
case 1:
Fragment fragment2 = new Fragment2();
FragmentTransaction transaction2 = getFragmentManager().beginTransaction();
transaction2.replace(R.id.car_fragment, fragment2);
transaction2.addToBackStack(null);
transaction2.commit();
break;
}
}
}
Fragment1
package in.cars.demo;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Fragment1 extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment1, container, false);
}
}
Fragment2
package in.cars.demo;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Fragment2 extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment2, container, false);
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<fragment
android:id="#+id/car_fragment"
android:name="in.cars.demo.CarsList"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>
cars_container.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="4dp"
android:paddingRight="4dp">
<ListView android:id="#id/android:list"
android:layout_width="match_parent"
android:layout_height="0dip"
android:layout_weight="1"/>
</LinearLayout>
fragment1.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/frag1TV"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Hello! It's a Buick" />
</LinearLayout>
fragment2.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/frag2TV"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Hello! It's a Mazda" />
</LinearLayout>

The problem is that you set the layout_height of your fragment to wrap_content in your main.xml. The visible size will be reduced to the actual size of the fragment.
Change it to match_parent to fill the whole screen:
...
<fragment
android:id="#+id/car_fragment"
android:name="in.cars.demo.CarsList"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
...
Furthermore use match_parent instead of fill_parent in apps with API Level 8+. See this question for more information.
Edit:
You have to change the container for the Fragments. The Fragment set with the tag will be static. Every fragment will be set in addition to this container. To have a dynamic approach use a FrameLayout. Now you can replace the fragment which was in there before.
...
<FrameLayout
android:id="#+id/car_fragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
...
To show your CarsList you have to do a Fragment transaction in your Activity.
getFragmentManager() / getSupportFragmentManager()
.beginTransaction()
.replace(R.id.car_fragment, new CarsList())
.addToBackstack(null)
.commit();

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white"
android:clickable="true"
android:orientation="vertical">
Try to setUp a color background to your fragment. In this way the background covers the entire space.

It is a little bit late, but maybe I will help someone else. The problem is with 'fragment' in your activity xml layout file (main.xml). You have to change:
<fragment
android:id="#+id/car_fragment"
android:name="in.cars.demo.CarsList"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
to
<fragment
android:id="#+id/car_fragment"
android:name="in.cars.demo.CarsList"
android:layout_width="match_parent"
android:layout_height="match_parent"/>

Fragment doesn't work

I have main layout like this
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<Button
android:id="#+id/btn_showdetails"
android:layout_width="100dip"
android:layout_height="wrap_content"
android:layout_marginLeft="110dip"
android:layout_marginTop="15dip"
android:text="Show Details" />
</LinearLayout>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal"
android:id="#+id/my_parent_layout"
>
</LinearLayout>
</LinearLayout>
am trying to call another activity in the my_parent_layout using this class
package com.appnetics;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.view.View;
import android.widget.Button;
public class FragmenttestActivity extends FragmentActivity {
Button LogIn = null ;
final FragmentManager fragmentManager = getSupportFragmentManager() ;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LogIn = (Button) findViewById(R.id.btn_showdetails);
LogInEvent() ;
}
public void LogInEvent(){
LogIn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
details fragment = new details();
fragmentTransaction.add(R.id.my_parent_layout, fragment);
fragmentTransaction.commit();
}
});
}
}
the details layout is :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/date_time_label"
android:layout_centerVertical="true"
android:layout_marginLeft="200dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="32dp"
android:textStyle="bold"
android:text="time_label"
/>
<TextView
android:id="#+id/last_view_time"
android:layout_toRightOf="#+id/date_time_label"
android:layout_alignBaseline="#+id/date_time_label"
android:layout_marginLeft="8dip"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="32dp"
/>
</LinearLayout>
and the layout code is
/* $Id: $
*/
package com.appnetics;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
/**
* DateTime
*/
public class details extends Fragment {
private static String getDateTimeString(Date time) {
return new SimpleDateFormat("d MMM yyyy HH:mm:ss")
.format(time);
}
private final String time = getDateTimeString(new Date());
/** #see android.app.Fragment#onCreateView(android.view.LayoutInflater, android.view.ViewGroup, android.os.Bundle) */
#Override
public View onCreateView(
LayoutInflater inflater,
ViewGroup container,
Bundle b)
{
View view = inflater.inflate(
R.layout.details,
container,
false); //!!! this is important
((TextView) view.findViewById(R.id.last_view_time))
.setText(time);
return view;
}
}
the problem is that when click the button, nothing appear , any idea what's wrong in my code

Lets start!
On your details XML:
android:layout_toRightOf="#+id/date_time_label"
android:layout_alignBaseline="#+id/date_time_label"
this two tags are for relative layouts, the parent of the layouts must be of relative type in order to work.
android:layout_centerVertical="true"
This tag is also incorrect, if you want to center the text in the textview you can use two ways or wrap content in textView and set center in its parent or use:
android:gravity="right"
android:width="fill_parent"
This will be the detail_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/date_time_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="32dp"
android:textStyle="bold"
android:text="time_label"
/>
<TextView
android:id="#+id/last_view_time"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="right"
android:text="view time"
android:textSize="32dp" />
</LinearLayout>
On your main.xml you declare the schema lots of times! should be declared once on your root layout.
LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
So the main.xml will be...
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center_horizontal"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/hello" />
<Button
android:id="#+id/add_fragment"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
<LinearLayout
android:id="#+id/fragment_holder"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
</LinearLayout>
</LinearLayout>
The fragment is an element that is declared in its class and apply its xml.
public class DetailsFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment, container, false);
}
}
And in the main activity add it to the holder layout:
public class FragmentSimpleTestActivity extends FragmentActivity {
private Button addFragment;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final FragmentManager fragmentManager = getSupportFragmentManager();
addFragment = (Button) findViewById(R.id.add_fragment);
addFragment.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
DetailsFragment fragment = new DetailsFragment();
fragmentTransaction.add(R.id.fragment_holder,fragment, "MY_FRAG");
fragmentTransaction.commit();
}
});
}
}
Its important that fragmentTransaction.add has parameters
1: the id of the view to hold the fragment.
2: the fragment object.
3: a tag that is used to find the fragments in the stack.
and thats all :)
Enjoy your fragments! you can also set animations when adding or removing it.

onCreateView()
The system calls this when it's time for the fragment to draw its user interface for the first time. To draw a UI for your fragment, you
must return a View from this method that is the root of your
fragment's layout. You can return null if the fragment does not
provide a UI.
Call OnCreateView in your fragment class
return inflater.inflate(R.layout.fragmentlayout, container, false);

I had a similar problem, when fragment wasn't showing up. The problem was that I removed AndroidAnnotations, but forgot to move the code from onViewCreated and onCreate methods to the onCreateView. I found this mistake by comparing the code of two fragments - one, that was showing up and the other that wasn't. So, if you have similar problems, try to check the code of fragments. It may not show any errors at first glance, but will not still work or show up because of those errors.
Particularly, check that you have this method and that you inflate a view:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.your_fragment_layout, container, false);
return v;
}