Fragment loses its state when rotate device twice - android

I have an activity which displays two fragments:
When activity is created, it displays Fragment1.
When the user presses the button on Fragment1, it displays Fragment2, adding to backstack.
Fragments are straightforward. Fragment1 contains CheckBox and EditText. Fragment2 contains simple TextView. Also I call setRetainInstance(true) in fragment's onCreate(...) method.
Problem: Fragment1 loses its state if Fragment2 is displayed and device is rotated twice. However, everything works as expected if device is rotate only once.
Steps to reproduce:
Launch application.
Check CheckBox and type some text into EditText
Press Button to launch Fragment2
Rotate device
Rotate device once again
Press Back button on your device (or ESC on Emulator) to return back to Fragment1
Fragment1 lost its state (checkbox is unchecked and EditText is empty).
However, if you return back to Fragment1 after step#4 - Fragment1 keeps its state as expected.
Where is the problem? All code is below, including layouts.
main.xml:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/placeholder"
android:layout_width="match_parent"
android:layout_height="match_parent" />
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" >
<CheckBox
android:id="#+id/checkBox1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CheckBox" />
<EditText
android:id="#+id/editText1"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</EditText>
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Start Fragment2" />
</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/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Fragment #2" />
</LinearLayout>
FragmentTestActivity.java:
package fragmenttest.example.com;
import android.app.Activity;
import android.app.FragmentManager;
import android.os.Bundle;
public class FragmentTestActivity extends Activity implements FragmentListener {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
FragmentManager fm = getFragmentManager();
if (fm.findFragmentByTag(Fragment1.TAG) == null) {
fm.beginTransaction().replace(R.id.placeholder, new Fragment1(), Fragment1.TAG).commit();
}
}
#Override
public void onButtonClick() {
FragmentManager fm = getFragmentManager();
if (fm.findFragmentByTag(Fragment2.TAG) == null) {
fm.beginTransaction().replace(R.id.placeholder, new Fragment2(), Fragment2.TAG).addToBackStack(Fragment2.TAG).commit();
}
}
}
Fragment1.java:
package fragmenttest.example.com;
import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
public class Fragment1 extends Fragment {
public static final String TAG = Fragment1.class.getName();
private FragmentListener mListener;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRetainInstance(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment1, container, false);
Button button = (Button) root.findViewById(R.id.button1);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
mListener.onButtonClick();
}
});
return root;
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
mListener = (FragmentListener) activity;
}
}
Fragment2.java:
package fragmenttest.example.com;
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 {
public static final String TAG = Fragment2.class.getName();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRetainInstance(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment2, container, false);
return root;
}
}
FragmentListener.java:
package fragmenttest.example.com;
public interface FragmentListener {
public void onButtonClick();
}

It may be because onCreate isn't called when restoring the fragment.
See:http://developer.android.com/reference/android/app/Fragment.html#setRetainInstance(boolean)

Related

Nested fragments - Screen of Frag2 stays empty

I'm suffering through nested fragments. I have a mainactivity which calls a fragment 1 which in turns call a fragment via a button. The fragment frag2 is well instantiated but the screen is blank.
Is there something obvious with my code?
MainActivity
import android.app.FragmentManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentManager fragmentManager;
Frag1 f1 = new Frag1();
fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame,
f1).commit();
}
}
mainactivity xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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="match_parent"
tools:context="com.narb.nestedfragments.MainActivity">
<FrameLayout
android:id="#+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</RelativeLayout>
Fragment 1 and its xml layout:
import android.app.FragmentTransaction;
import android.content.Context;
import android.os.Bundle;
import android.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.RelativeLayout;
/**
* A simple {#link Fragment} subclass.
*/
public class Frag1 extends android.app.Fragment {
Context context;
private Button back1;
RelativeLayout rl1;
public Frag1() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootview = null;
rootview = inflater.inflate(R.layout.fragment_frag1, container, false);
return rootview;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
context = getActivity().getApplicationContext();
initFindView();
back1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Log.i("frag1","createdview");
//getActivity().getFragmentManager().popBackStackImmediate();
rl1.setVisibility(View.INVISIBLE);
FragmentTransaction ft = getFragmentManager().beginTransaction();
Frag2 f2 = new Frag2();
ft.replace(R.id.fl1, f2);
ft.addToBackStack(null);
ft.commit();
}
});
}
private void initFindView(){
back1 = (Button) getActivity().findViewById(R.id.btn1);
rl1 = (RelativeLayout) getActivity().findViewById(R.id.rl1);
}
}
Is it normal that I need to make my layout frag 1 invisible before calling frag2?
and finally my fragment 2 and its layout. I see the log for frag 2 but the screen is empty:
import android.app.Fragment;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
public class Frag2 extends Fragment {
Context context;
private Button btn2;
public Frag2() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootview;
rootview = inflater.inflate(R.layout.fragment_frag2, container, false);
Log.i("frag2","createdview");
return rootview;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
context = getActivity().getApplicationContext();
Log.i("frag2","onactivitycreated");
btn2 = (Button) getActivity().findViewById(R.id.btn2);
btn2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Log.i("frag2","onactivitycreated");
}
});
}
}
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.narb.nestedfragments.Frag2">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Test 2" />
<Button
android:id="#+id/btn2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="60dp"
android:text="back"
/>
</RelativeLayout>
if your fragment 1 is having another FrameLayout where you are replacing fragment 2, then instead of getFragmentManager(), use getChildFragmentManager() in fragment 1
otherwise you are passing wrong container id in replace() method R.id.fl1 inside fragment1. you should pass R.id.content_frame there.
You have not posted the fragment1 XML Code. lets assume RelativeLayout (rl1) is your parent layout and you have FrameLayout (fl1) inside the rl1. You are making the parent layout invisible. So the fragment2 can't be visible.
If you don't want to show the fragment1 while showing there is no need for the nested fragment.
You should call like this to load second fragment.
getFragmentManager().beginTransaction()
.replace(R.id.content_frame ,new Frag2());
.addToBackStack(null);
.commit();
use content_frame id of activity_main in Frag1 class
back1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Log.i("frag1", "createdview");
//getActivity().getFragmentManager().popBackStackImmediate();
rl1.setVisibility(View.INVISIBLE);
FragmentTransaction ft = getFragmentManager().beginTransaction();
Frag2 f2 = new Frag2();
ft.replace(R.id.content_frame, f2);
ft.addToBackStack(null);
ft.commit();
}
});

How to pass data between fragments of a FragmentTabHost?

I'm trying to learn android and am having an issue with this project. I have set up a fragment tab host with four fragments. What I would like to do is have the first three fragments be interactive with the user and when they tab over to the 4th tab, it will display all the information they put in on the first three. I figured I can pass the info overriding on onPause() as the trigger as I don't want to use a button press. Right now, I'm just trying to get the EditText to work to make sure I'm doing everything right. I'm not sure if I'm using the fragment transaction correctly, or the way I'm trying to collect the edit text field. Later on I hope to pass the information via a bundle. Any help would be appreciated.
Main:
package valdes.fragmenttabsmenu;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTabHost;
import android.app.FragmentTransaction;
public class MainActivity extends FragmentActivity implements WelcomeFragment.WelcomeListener {
private FragmentTabHost mTabHost;
private String firstName;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTabHost = (FragmentTabHost) findViewById(android.R.id.tabhost);
mTabHost.setup(this, getSupportFragmentManager(), android.R.id.tabcontent);
mTabHost.addTab(mTabHost.newTabSpec("Home").setIndicator("Home", null), WelcomeFragment.class, null);
mTabHost.addTab(mTabHost.newTabSpec("Demographics").setIndicator("Demographics", null), DemographicsFragment.class, null);
mTabHost.addTab(mTabHost.newTabSpec("Questions").setIndicator("Questions", null), QuestionsFragment.class, null);
mTabHost.addTab(mTabHost.newTabSpec("Overview").setIndicator("Overview", null), OverviewFragment.class, null);
}
#Override
public void getFristName(String first_Name){
firstName = first_Name;
OverviewFragment fragment = new OverviewFragment();
FragmentTransaction ft = getFragmentManager().beginTransaction();
fragment.setFirstName(firstName);
ft.addToBackStack(null);
ft.commit();
}
}
Fragment 1 - getting info
package valdes.fragmenttabsmenu;
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.text.TextWatcher;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
public class WelcomeFragment extends Fragment {
public WelcomeFragment() {
// Required empty public constructor
}
interface WelcomeListener{
public void getFristName(String firstName);
}
private WelcomeListener listener;
private String firstName;
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_welcome, container, false);
EditText editText = (EditText) view.findViewById(R.id.first_name);
firstName = editText.getText().toString();
return view;
}
#Override
public void onAttach(Context context){
super.onAttach(context);
this.listener = (WelcomeListener)context;
}
#Override
public void onPause(){
super.onPause();
if(listener != null){
listener.getFristName(firstName);
}
}
}
Fragment 1 XML
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="#dimen/activity_horizontal_margin">
<TextView
android:id="#+id/welcome"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_gravity="center_horizontal"
android:textSize="25sp"
android:text="#string/welcome_message"/>
<EditText
android:id="#+id/first_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="#string/first_name"/>
<EditText
android:id="#+id/last_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="#string/last_name"/>
<Spinner
android:id="#+id/birthday"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:entries="#array/months"/>
</LinearLayout>
Fragment 2 - getting info
package valdes.fragmenttabsmenu;
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;
public class OverviewFragment extends Fragment {
private String firstName;
private String lastName;
public OverviewFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_overview, container, false);
}
#Override
public void onStart(){
super.onStart();
View view = getView();
if(view != null){
TextView name = (TextView) view.findViewById(R.id.OV_name);
name.setText(firstName);
}
}
public void setFirstName(String firstName){this.firstName = firstName;}
}
Fragment 2 XML
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="valdes.fragmenttabsmenu.OverviewFragment">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_gravity="center_horizontal"
android:textSize="25sp"
android:layout_weight="1"
android:text="#string/overview"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_gravity="center_horizontal"
android:textSize="40sp"
android:text="Responses go here"/>
<TextView
android:id="#+id/OV_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="TEST"/>
<Button
android:id="#+id/submit_button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/submit"/>
</LinearLayout>
Create a Listner for get/set data between fragments and implement it on activity like this
InteractionLister.java
public interface InteractionLister {
void setData(String data);
String getData();
}
MainActivity.java
public class TabActivity extends Activity implements InteractionLister{
private String mData;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public void setData(String data) {
this.mData = data;
}
#Override
public String getData() {
return mData;
}
}
TabFragment1.java
public class TabFragment1 extends Fragment {
InteractionLister interactionLister;
private static final String TAG = TabFragment1.class.getSimpleName();
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
Log.w(TAG,"Data from other fragment " + interactionLister.getData());
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
interactionLister = (InteractionLister) activity;
}
}

Fragment A Notify Fragment B

I have a function1 in FragA, and a function2 in FragB
What I want is : when FragA use function1, it should notify FragB to use functionB
So what is the easiest and good way to do it ?
Thanks
1. Using an EventBus
Use an EventBus to send event to the other fragment. You can try Otto or EventBus
2. Using FragmentManager and public method (I don't like these)
As #Alexander suggested, you can get reference to the other fragment and call its method
3. Using Broadcasts
You can use a LocalBroadcast and attach a receiver in both fragments to call the method when they receive a broadcast.
following is the example for your question, well it's quite crude in code but will give you an idea about how you can implement your requirement.
your activity should look like this FragmentTestOneActivity.java
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import test.spinner.one.FragmentA;
import test.spinner.one.FragmentB;
public class FragmentTestOneActivity extends AppCompatActivity implements FragmentA.MyEventMaker{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fragment_test_one);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
}
#Override
public void sendData(String text) {
Log.d("FragmentTestOneActivity", "Text: "+text);
FragmentB.setData(text);
}
}
and below is the layout for the above activity activity_fragment_test_one.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="match_parent"
android:background="#cf5f5b"
android:orientation="horizontal"
android:padding="10dp"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context="some.fragment.one.FragmentTestOneActivity"
tools:showIn="#layout/activity_fragment_test_one">
<fragment
android:id="#+id/fragment_one"
android:name="test.spinner.one.FragmentA"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_margin="4dp"
android:layout_weight="0.5"
tools:layout="#layout/fragment_" />
<fragment
android:id="#+id/fragment_two"
android:name="test.spinner.one.FragmentB"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_margin="4dp"
android:layout_weight="0.5"
tools:layout="#layout/fragment_b" />
</LinearLayout>
FragmentA.java
import android.content.Context;
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.Button;
/**
* A simple {#link Fragment} subclass.
*/
public class FragmentA extends Fragment {
private MyEventMaker myEventMaker;
private Button button;
public FragmentA() {
// Required empty public constructor
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
myEventMaker = (MyEventMaker)context;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_, container, false);
button = (Button) view.findViewById(R.id.FragmentA_button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
myEventMaker.sendData("something");
}
});
return view;
}
public interface MyEventMaker{
void sendData(String text);
}
}
fragment_a.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:background="#b1a2f3"
tools:context="test.spinner.one.FragmentA">
<Button
android:id="#+id/FragmentA_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Button" />
</LinearLayout>
FragmentB
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
/**
* A simple {#link Fragment} subclass.
*/
public class FragmentB extends Fragment {
private static TextView textView;
public FragmentB() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view =inflater.inflate(R.layout.fragment_b, container, false);
textView = (TextView)view.findViewById(R.id.FragmentB_textView);
return view;
}
public static void setData(String text){
Log.d("FragmentB","Text: "+ text);
textView.setText(""+text);
}
}
fragment_b.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#efabca"
android:gravity="center"
tools:context="test.spinner.one.FragmentB">
<TextView
android:id="#+id/FragmentB_textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="" />
</LinearLayout>
From func1 find your B fragment using FragmentManager.findFragmentByTag (or byId) then call your function on that fragment.
Or you can use a 3rd party even bus such as Otto

Android FragmentTransaction won't add or replace fragment to container

This question has been asked before, however, I have not found an appropriate answer for my problem. I am building a simple fragment activity that displays three buttons at the top of the screen in one container that when pressed update the fragment in the rest of the screen. Just like a tab host. I am using android.support.v4.app.Fragment in all code, but still cannot get the transaction manager to display the fragment in the container. I've been banging my head on the keyboard for hours and connot find the problem.
Here is the main activity extending FragmentActivity:
package com.example.testudpfragment;
import com.example.testudp.R;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
public class TestUDPFragmentActivity extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test_udpfragment);
if(savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.menu_container, new MenuFragment()).commit();
}
}
}
Here is the MenuFragment class extending fragment for my tabs:
package com.example.testudpfragment;
import com.example.testudp.R;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.support.v4.app.*;
public class MenuFragment extends Fragment{
Fragment frag;
FragmentTransaction fragTransaction;
public MenuFragment() {
}
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.frament_menu, container, false);
frag = new StringsFragment();
fragTransaction = getFragmentManager().beginTransaction().add(R.id.container, frag);
System.out.println(fragTransaction.toString());
fragTransaction.commit();
Button btnString = (Button) view.findViewById(R.id.button_string);
Button btnSlider = (Button) view.findViewById(R.id.button_slider);
Button btnTouch = (Button) view.findViewById(R.id.button_touch);
btnString.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
frag = new StringsFragment();
fragTransaction = getFragmentManager().beginTransaction().replace(R.id.container, frag);
fragTransaction.commit();
}
});
btnSlider.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
frag = new SlidersFragment();
fragTransaction = getFragmentManager().beginTransaction().replace(R.id.container, frag);
fragTransaction.commit();
}
});
btnTouch.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
frag = new TouchFragment();
fragTransaction = getFragmentManager().beginTransaction().replace(R.id.container, frag);
fragTransaction.commit();
}
});
return view;
}
}
Here is one of the three fragments that I can't get to display:
package com.example.testudpfragment;
import com.example.testudp.R;
import android.support.v4.app.*;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class StringsFragment extends Fragment {
public StringsFragment() {
}
public View onCreatView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_strings, null);
return rootView;
}
}
activity_test_udpfragment:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<FrameLayout
android:id="#+id/menu_container"
android:background="#eee"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</FrameLayout>
<FrameLayout
android:id="#+id/container"
android:background="#aaa"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
</LinearLayout>
Here is frament_menu:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
style="android.att/buttonBarStyle" >``
<Button
android:id="#+id/button_string"
style="android.att/buttonBarButtonStyle"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="String" />
<Button
android:id="#+id/button_slider"
style="android.att/buttonBarButtonStyle"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Slider" />
<Button
android:id="#+id/button_touch"
style="android.att/buttonBarButtonStyle"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Touch" />
</LinearLayout>
And here is fragment_strings:
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:scaleType = "centerCrop"
android:src="#drawable/me_hooded" />
</RelativeLayout>
Any help is greatly appreciated!
EDIT:
Here is new TestUDPActivityFragment with buttons to change fragment:
package com.example.testudpfragment;
import com.example.testudp.R;
import android.support.v4.app.*;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.os.Bundle;
public class TestUDPFragmentActivity extends FragmentActivity {
Fragment frag;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test_udpfragment);
Button btnString = (Button)findViewById(R.id.btn_string);
Button btnSlider = (Button)findViewById(R.id.btn_slider);
Button btnTouch = (Button)findViewById(R.id.btn_touch);
if(savedInstanceState == null) {
getSupportFragmentManager().beginTransaction().add(R.id.container, new StringsFragment()).commit();
btnString.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
frag = new StringsFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.container, frag).commit();
}
});
btnSlider.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
frag = new SlidersFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.container, frag).commit();
}
});
btnTouch.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
frag = new TouchFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.container, frag).commit();
}
});
}
}
}
I can see a couple of problems...
First, your FrameLayout containers are defined in your activity_test_udpfragment.xml layout file which is inflated by your TestUDPFragmentActivity. The problem with attempting to create / add your StringsFragment in your MenuFragment code using the following...
fragTransaction = getFragmentManager().beginTransaction().add(R.id.container, frag);
...is the MenuFragment inflates a layout from your frament_menu.xml which doesn't contain a FrameLayout with id of R.id.container.
That's your first problem but the second is with attempting to use a Fragment to create / add a Fragment in the first place. Your MenuFragment is not able to use the Framelayout in the TestUDPFragmentActivity.
In short, I suspect you want both Fragments to appear in your Activity layout (and not have the StringsFragment as a 'child' of MenuFragment) in which case you need to put all code for creating / adding both Fragments into your Activity.

Android: Error when triggering fragment from within the fragment itself

I'm trying to learn fragments on android and my code is not working.
FragmentCustomAnimations contains MainActivity.
What i want is the frame MainActivity to change when i push the button on MainActivity.
The error message on logcat is Could not find a method sendMessage(View) in the activity class com.example.myfirstapp.FragmentCustomAnimations for onClick handler on view class android.widget.Button with id 'button1'
Eventhough there is no function sendmessage in all my file.
FYI, its working when i put the button on FragmentCustomAnimations.
Is it impossible to use the button on fragment to trigger action to change the fragment itself?
Here is the code:
FragmentCustomAnimations.java
package com.example.myfirstapp;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class FragmentCustomAnimations extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_stack);
if (savedInstanceState == null) {
Fragment newFragment = InitialFragment.newInstance();
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.add(R.id.simple_fragment, newFragment).commit();
}
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
}
public static class InitialFragment extends Fragment {
static InitialFragment newInstance() {
InitialFragment f = new InitialFragment();
Bundle args = new Bundle();
f.setArguments(args);
return f;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.activity_main, container, false);
return v;
}
}
}
fragment_stack.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:padding="4dip"
android:gravity="center_horizontal"
android:background="#drawable/window2x"
android:layout_width="match_parent" android:layout_height="match_parent">
<FrameLayout
android:id="#+id/simple_fragment"
android:layout_width="match_parent"
android:layout_height="0px"
android:layout_weight="1">
</FrameLayout>
</LinearLayout>
MainActivity.java
package com.example.myfirstapp;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
public class MainActivity extends Activity implements OnClickListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button inner = (Button) findViewById(R.id.button1);
inner.setOnClickListener(this);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu items for use in the action bar
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
getActionBar().setDisplayShowHomeEnabled(false);
return super.onCreateOptionsMenu(menu);
}
#Override
public void onClick(View v) {
addFragmentToStack();
}
void addFragmentToStack() {
Fragment newFragment = CountingFragment.newInstance();
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.setCustomAnimations(R.animator.fragment_slide_left_enter,
R.animator.fragment_slide_left_exit,
R.animator.fragment_slide_right_enter,
R.animator.fragment_slide_right_exit);
ft.replace(R.id.simple_fragment, newFragment);
ft.addToBackStack(null);
ft.commit();
}
public static class CountingFragment extends Fragment {
static CountingFragment newInstance() {
CountingFragment f = new CountingFragment();
Bundle args = new Bundle();
f.setArguments(args);
return f;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.activity_display_message, container, false);
return v;
}
}
}
activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="?android:attr/actionBarSize"
android:layout_gravity="center_vertical"
tools:context=".MainActivity" >
<EditText
android:id="#+id/edit_message"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="#string/edit_message"
android:layout_gravity="center_vertical"
android:inputType="textPersonName" >
<requestFocus />
</EditText>
<EditText
android:id="#+id/editTextEmail"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="#string/editTextEmail"
android:inputType="textEmailAddress" />
<EditText
android:id="#+id/editTextPassword"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="#string/editTextPassword"
android:inputType="textPassword" />
<Button
android:id="#+id/button1"
style="#style/CodeFont"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:background="#drawable/custom_button"
android:text="#string/button_send" />
</LinearLayout>

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