I'm trying to get my head around fragments in order to have my apps prepped for ICS.
I have the following files to just get the most basic fragment app you can have. It should have this when launched: One Fragment Layout with a text view "Fragment 1" and next to it another Fragment Layout with "Fragment2".
My package name is com.mwerner.fragments
My files are:
FragmentsActivity.java
ExamplesFragment.java
ExamplesFragment2.java
examples_fragment.xml
examples_fragment2.xml
main.xml
The code for FragmentsActivity.java is:
package com.mwerner.fragments;
import android.app.Activity;
import android.os.Bundle;
public class FragmentsActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
ExamplesFragment.java
package com.mwerner.fragments;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class ExamplesFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.examples_fragment, container, false);
}
}
ExamplesFragment2.java
package com.mwerner.fragments;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class ExamplesFragment2 extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.examples_fragment2, container, false);
}
}
The examples_fragment.xml files just have a linear layout with a textview in it...
Here is the code for the 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
class="com.mwerner.fragments$ExamplesFragment"
android:id="#+id/list"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="fill_parent"
/>
<fragment
class="com.mwerner.fragments$ExamplesFragment2"
android:id="#+id/viewer"
android:layout_weight="2"
android:layout_width="0dp"
android:layout_height="fill_parent" />
</LinearLayout>
The app crashes on startup with the error
11-07 18:12:12.519: E/AndroidRuntime(696): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mwerner.fragments/com.mwerner.fragments.FragmentsActivity}: android.view.InflateException: Binary XML file line #7: Error inflating class fragment
Can you please tell me what is wrong here? I pretty much copied / pasted the code from the google developers page for fragments.
You defined the path to your fragments incorrectly in your layout xml. Correct the class attributes. Try 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="vertical" >
<fragment
class="com.mwerner.fragments.ExamplesFragment"
android:id="#+id/list"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="fill_parent"
/>
<fragment
class="com.mwerner.fragments.ExamplesFragment2"
android:id="#+id/viewer"
android:layout_weight="2"
android:layout_width="0dp"
android:layout_height="fill_parent" />
</LinearLayout>
Try extending FragmentActivity
public class FragmentsActivity extends FragmentActivity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
When I was writing my first program on Fragments using I incurred same error. Instead of extending "Activity" extend "FragmentActivity" in your launcher activity.
Related
Here is the class of fragment
package com.hfad.chapter7;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class WorkoutDetailFragment extends Fragment {
private long workoutID;
public WorkoutDetailFragment() {
// 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_workout_detail, container, false);
}
public void setWorkoutID(long workoutID) {
this.workoutID = workoutID;
}
}
And the layout it's using is:
<FrameLayout 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.hfad.chapter7.WorkoutDetailFragment">
<!-- TODO: Update blank fragment layout -->
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="#string/hello_blank_fragment" />
</FrameLayout>
My MainActivity is:
package com.hfad.chapter7;
import android.app.Activity;
import android.app.Fragment;
import android.provider.UserDictionary;
import android.support.v4.app.FragmentActivity;
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);
WokoutDetailFragment workoutDetailFragment;
workoutDetailFragment = (WorkoutDetailFragment)this.getFragmentManager().findFragmentById(R.id.myFirstFragment);
}
}
And layout of MainActivity is:
<?xml version="1.0" encoding="utf-8"?>
<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:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.hfad.chapter7.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!"
/>
<fragment
class="com.hfad.chapter7.WorkoutDetailFragment"
android:id="#+id/myFirstFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</LinearLayout>
Problem is when I use this.getFragmentManager().findFragmentById(R.id.myFirstFragment) in onCreate of AppCompatActivity I get Fragment though I should get WorkoutDetailFragment as stated here in a similar example.
UPDATE:
Also I am unable to cast Fragment to WorkDetailFragment
#user4913383,
Change this line:
workoutDetailFragment = (WorkoutDetailFragment)this.getFragmentManager().findFragmentById(R.id.myFirstFragment);
to
workoutDetailFragment = (WorkoutDetailFragment)this.getSupportFragmentManager().findFragmentById(R.id.myFirstFragment);
What's the problem of getting a fragment? The getFragmentManager().findFragmentById() method returns a Fragment and you have to cast it. Since you are casting the Fragment to a WorkoutDetailFragment you should be able to do what you want with it.
I think it has to be <fragment android:name="com.hfad.chapter7.WorkoutDetailFragment"... instead of class.
=> http://developer.android.com/training/basics/fragments/creating.html#AddInLayout
i have problems to use a fragment in a fragment. The first fragment is a tab view an in one tab i want to have a multi-pane Layout like this:
The error is:
android.view.InflateException: Binary XML file line #8: Error
inflating class fragment
The tab fragment (SettingsFragmentBox):
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class SettingsFragmentBox extends Fragment implements SettingsFragmentBoxList.OnItemSelectedListener{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_settings_box, container, false);
return rootView;
}
public void onBoxSelect(int id) {
SettingsFragmentBoxDetail fragment = (SettingsFragmentBoxDetail) getFragmentManager().findFragmentById(R.id.box_detail);
if (fragment != null && fragment.isInLayout()) {
fragment.setText(id);
} else {
Intent intent = new Intent(getActivity(),SettingsActivityBoxDetail.class);
intent.putExtra(SettingsActivityBoxDetail.EXTRA_ID, id);
startActivity(intent);
}
}
}
The xml (fragment_settings_box.xml):
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >
<fragment
android:id="#+id/box_list"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
class="de.resper.e2cast.SettingsFragmentBoxList"
tools:layout="#layout/fragment_settings_box_list">
</fragment>
<fragment
android:id="#+id/box_detail"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="2"
class="de.resper.e2cast.SettingsFragmentBoxDetail"
tools:layout="#layout/fragment_settings_box_detail">
</fragment>
</LinearLayout>
Usually this is done using fragments in ACTIVITIES, not in other fragments. Are you sure you really want fragments in other fragments ?
The picture you are referring to is by the way showing this scenario (ACTIVITIES contain fragment A or B).
You should read http://developer.android.com/training/multiscreen/screensizes.html to handle different screensizes. There is an example with a layout containt two fragments in it. Also learn how to adapt to it by reading this http://developer.android.com/training/multiscreen/adaptui.html
I am hardly trying to create a simple application with a top menu and a changeable view below (by pressing the buttons in the menu fragment we change the view of the fragment below).
So, I have 2 fragments inside the main view but when trying to run the application in the emulator I get an error like:
Cause by android.app (bla bla bla, piece of crap Eclipse doesn't even allow copying the errors):
Trying to instantiate a class com.example.android.topmenu that is not a fragment
So, these are my XML layouts:
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<fragment
android:id="#+id/menuFragment"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:name="com.example.android.topmenu" >
</fragment>
<fragment
android:id="#+id/contentFragment"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:name="com.example.android.bottomcontent" >
</fragment>
</LinearLayout>
topmenu.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="horizontal" >
<Button
android:id="#+id/Button1"
android:layout_width="wrap_content"
android:layout_height="match_parent" />
</LinearLayout>
bottom_content.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:padding="10dp"
android:orientation="vertical">
<TextView
android:id="#+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#+string/content_text" />
</LinearLayout>
and these are the classes for the main activity and the fragments
main_activity
package com.example.android;
import com.example.android.R;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
public class OLife extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
// The activity is being created
super.onCreate(savedInstanceState);
// Set view
setContentView(R.layout.main);
}
#Override
protected void onDestroy() {
super.onDestroy();
// The activity is about to be destroyed.
super.onDestroy();
// Stop method tracing that the activity started during onCreate()
android.os.Debug.stopMethodTracing();
}
}
topmenu
package com.example.android;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class OLifeMenu extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.topmenu, container, false);
return view;
}
}
bottomcontent
package com.example.android;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class OLifeMain extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.bottom_content, container, false);
return view;
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
}
}
You should be using FragmentActivity instead of Activity that is because you are using support Fragments and multiple Fragments in your activity main
Edit
You can now use the Appcompat support library and extends AppCompatActivity to support toolbar and fragment for lower api.
In my case it turned out, I was doing stuff in onCreate in the wrong order:
setContentView(R.layout.activity_qr_code_scan);
super.onCreate(savedInstanceState);
instead of
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_qr_code_scan);
As you are using fragments in your layout and I suggest you to extend your class from fragment or fragment activity.
I created a basic project using Intellij 13 and android sdk 19 then I add support-library v4.jar to my project.
this is my main activity :
package com.example.testfg2;
import android.app.Activity;
import android.os.Bundle;
public class MyActivity extends Activity {
/**
* Called when the activity is first created.
*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
this is "main.xml" layout
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Hello World, MyActivity"
/>
<fragment android:layout_width="wrap_content" android:layout_height="wrap_content"
name="com.example.testfg2.frg1"
/>
</LinearLayout>
this is my simple fragment class "frg1.java"
package com.example.testfg2;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class frg1 extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.frg_layout, container, false);
}
}
and here is the layout "frg_layout.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">
</LinearLayout>
my emulator is a 2.3.3.
when I try to run this app I will get following error :
Caused by: android.view.InflateException: Binary XML file line #12:
Error inflating class fragment
What do I exactly missed? is there anything extra I should do to make the app working with intellij 13.0 ?
Your class should extend FragmentActivity
public class MyActivity extends FragmentActivity {
http://developer.android.com/reference/android/support/v4/app/FragmentActivity.html
Base class for activities that want to use the support-based Fragment.
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"/>