I'm seeing an undesired appearance of my list fragment when I run my app on the phone emulator. On the tablet emulator it appears once but on the phone emulator it appears twice. How can I fix this error for the list to appear on the phone emulator only once?
MainActivity.java
public class MainActivity extends ActionBarActivity {
private boolean mTwoPane;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentMainList newFragment = new FragmentMainList();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.master_container, newFragment);
transaction.commit();
if (findViewById(R.id.detail_container) != null) {
mTwoPane = true;
}
}
}
activity_main.xml
<fragment
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/master_container"
android:name="com.apptacularapps.exitsexpertlondonlite.FragmentMainList"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".FragmentMainList"
tools:layout="#android:layout/list_content"/>
activity_main.xml (sw600dp)
<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="horizontal"
android:showDividers="middle"
tools:context=".MainActivity" >
<RelativeLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:id="#+id/master_container"/>
<FrameLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="3"
android:id="#+id/detail_container"/>
</LinearLayout>
FragmentMainList.java
public class FragmentMainList extends android.support.v4.app.Fragment {
ListView list_main;
String[] listContent = {
"Item 1",
"Item 2",
"Item 3"
};
private boolean mTwoPane;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View v = inflater.inflate(R.layout.fragment_main_list, container, false);
list_main = (ListView)v.findViewById(R.id.list_main);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),android.R.layout.simple_list_item_1,listContent);
list_main.setAdapter(adapter);
return v;
}
}
Please move the logic to add fragment inside the if loop you have.
Although you've already understood how to make it work, I'll try to explain how to make it work properly.
What you do is in fact this:
If on small screen - add the fragment statically (in XML)
If on larger screen - add the fragment dynamically (with FragmentTransaction)
It looks weird that the method by which you get the desired functionality depend on the screen size - there should be no correlation between these factors.
What you ought to do (IMHO) is to add this fragment dynamically in both cases - just change your Fragment tag in the first XML to FrameLayout and everything will work as expected.
Related
I have a Android fragment containing a ListView, and I have attached an ArrayAdapter to the ListView, but when I insert items into the ArrayAdapter, the ListView only shows the first item.
onCreateView iterates over my Technologies, if they're unlocked, it adds them to the ArrayList shownTechs, but only the first item ever appears
public class TabTechnologyList extends Fragment {
private static final String TAB_NAME = "tab_name";
private ListView techList;
private ArrayList<Technology> shownTechs = new ArrayList<>();
ArrayAdapter<Technology> techListAdapter;
public TabTechnologyList() { }
public static TabTechnologyList newInstance() {
TabTechnologyList fragment = new TabTechnologyList();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
tabData = Globals.getTabData();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_technology_list, container, false);
techList = (ListView) view.findViewById(R.id.tabTechListList);
techListAdapter = new ArrayAdapter<>(getActivity().getApplicationContext(), R.layout.layout_techlist_element, shownTechs);
techList.setAdapter(techListAdapter);
for(Technology tech: tabData.getTechnologies()) {
shownTechs.add(tech);
}
//Only the first one is shown on the screen
return view;
}
}
}
When I google for similar issues, people seem to be recreating the ArrayAdapter instead of editing the existing one, but I'm not doing that, and cant' figure out what problem remains. Any suggestions?
fragment_technology_list.xml:
<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.tbohne.kittens.front.TabTechnologyList"
>
<ListView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/tabTechListList" />
</RelativeLayout>
layout_techlist_element.xml
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</TextView>
Addition
I have just realized that this fragment is not filling the parent height, and is only tall enough to show the one entry, as if the fragment height were wrap_content. (I can't scroll it, so it appears as if there's only the one). This makes me think the nesting of fragments may be related, so here's the code that creates the fragment:
public class TabTechnology extends Fragment {
private TabTechnologyList table;
private OnFragmentInteractionListener mListener;
public TabTechnology() {}
public static TabTechnology newInstance(String tabName) {[SNIP]}
#Override public static onAttach(Activity activity) {[SNIP]}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_technology, container, false);
table = TabTechnologyList.newInstance(tabName);
FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
transaction.add(R.id.view_table, table);
transaction.commit();
return view;
}
}
fragment_technology.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"
tools:context="com.tbohne.kittens.front.TabTechnology"
android:orientation="vertical">
<ScrollView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:id="#+id/view_table"
android:layout_above="#+id/view_details" />
<View android:layout_width="match_parent"
android:layout_height="1px"
android:background="?android:attr/listDivider" />
<ScrollView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:id="#+id/view_details"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentRight="true" />
</LinearLayout>
Putting the Fragment inside the ScrollView was the source of the problem. Simply replaced those with FrameLayout, and suddenly everything magically works. Very strange.
I suspect the problem has something to do with nesting scrollable objects.
Solved! Thanks everyone for your help.
I am struggling with Fragments as a concept, and especially seem stuck on this one thing. What I'm trying to do is, using my fragment, manipulate its own layout's data. Every time I try to access an ImageButton from within the Fragment, it crashes the application. It works fine from the activity. Am I just misunderstanding Fragments fundamentally?
Code(cut down for size)-
This is the beginning of the activity my fragment is called from:
Display.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display);
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
MyFragmentClass MyFragment = new MyFragmentClass();
fragmentTransaction.add(R.id.fragment_container, MyFragment);
fragmentTransaction.commit();
The XML for that Activity:
activity_display.xml
<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"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context="com.mycompanyname.myprojectname.Display"
android:id="#+id/display_layout">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/fragment_container">
</FrameLayout>
</RelativeLayout>
The Fragment
MyFragmentClass.java
public class MyFragmentClass extends Fragment
{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_layout_screen, container, false);;
}
public void MethodTest()
{
}
}
The Fragment's XML file:
fragment_layout_screen.xml
<?xml version="1.0" encoding="utf-8"?>
<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"
android:id="#+id/fragment_layout_screen"
tools:context="com.mycompanyname.myprojectname.MyFragmentClass">
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/my_button"
android:clickable="true"
android:onClick="buttonPress"
android:src="#drawable/button"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"/>
</RelativeLayout>
Basically I had all of this originally in Display.java, but wanted to add fragments, so I'm trying to move stuff out and into fragments, but I still need the ability to manipulate the xml info, I just can't.
From inside the Display.java activity I can easily call the ImageButton like this:
ImageButton myButton = (ImageButton) findViewById(R.id.my_button)
but if I do the same from MethodTest in the fragment, the app crashes.
I've searched many suggestions on here, trying various solutions from here: findViewById in Fragment but none of those seemed to work.
I've been reading through this for the setup: http://developer.android.com/guide/components/fragments.html and can't seem to find what I'm doing wrong.
Any help would be appreciated, and if you have any questions about my setup, please ask.
declare on fragment private View rootView;
On the onCreateView(...) set rootView = inflater.Inflate(..); and then access the imagebutton as ImageButton mButton =(ImageButton) rootView.findViewById(..);
Do like this in fragment
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.gridview, container, false);
GridView gridview = (GridView) view.findViewById(R.id.grid);
return view ;
I've been trying to solve this for a while now, I've looked through quite a number of questions but still nothing works.
I have a MainActivity with a SlideMenu, all items open a Fragment. One of these Fragments extends to a ListFragment. What I'm trying to do is once a ListItem is selected another Fragment is called and displays some data...for now just a title.
When a ListItem is selected, I am creating an instance of the new Fragment, save the data in the Bundle and call the new Fragment to be displayed.
#Override
public void onListItemClick(ListView l, View v, int position, long id) {
// do something with the data
Article a = articleList.get(position);
Fragment articleFragment = new ArticleFragment();
Bundle args = new Bundle();
args.putString("title", a.title);
articleFragment.setArguments(args);
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.add(R.id.frame_container, articleFragment);
transaction.commit();
}
The onCreateView of the new Fragment attempts to set the text of the TextView with the Bundle's data.
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_pages, container, false);
TextView titleTextView = (TextView) rootView.findViewById(R.id.article_title);
String title = getArguments().getString("title");
titleTextView.setText(title);
return rootView;
}
The layout xmls are these two files:
activity_article_fragment.xml
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="info.androidhive.slidingmenu.ArticleFragment"
tools:ignore="MergeRootFrame" />
fragment_article.xml
<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"
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="info.androidhive.slidingmenu.ArticleFragment$PlaceholderFragment" >
<TextView
android:id="#+android:id/article_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
I've tried to do as many suggested...using the View to get the id from the xml (accessing textview within a fragment in activity, Android : How do I update my textView in a Fragment) but it's still null.
Whilst debugging everything is working but obviously stops when attempting to set the text of the TextView as it is null.
UPDATE
Just did as suggested by Karakuri...text being displayed but it looks like this:
I'm quite new to Android dev and I followed the official Android's "Get started".
The fact is, my fragment is not displayed on the main activity ( it worked well few days ago but I changed some lines, I don't remember which ones ). I think it's a very basic problem as I don't use sophisticated fragments : it's basically one fragment inside an activity.
This is my activity :
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container1"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.mysecond.MainActivity"
tools:ignore="MergeRootFrame" />
My fragment :
<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"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
</RelativeLayout>
And the java code for this activity (I have some other activities in the app, based on the same pattern "one fragment inside one activity" and they work well...)
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container1, new PlaceholderFragment()).commit();
}
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
return rootView;
}
}
}
Any ideas ?
Thank you :)
[edit]
so this is my new onCreate method :
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getSupportFragmentManager().beginTransaction().replace(
R.id.container1, new PlaceholderFragment()).commit();
}
Still not working for this activity (If I add a button in activity_main.xml I'll be able to see it but the I'm not able to see the TextView in the fragment...)
No errors in logcat and yes the activity is launched (I added some Log.e in onCreate and onCreateView and I cas see them)
In your onCreate methode you don't have to check if the savedInstanceState is null but if the the content of the FrameLayout you use is null
Or you simply always replace the fragment with a new one and ommit any checking.
Instead of add, you can use replace.
You can do it like below shown code:
getSupportFragmentManager().beginTransaction().replace(
R.id.container1, new PlaceholderFragment());
For me this work. Implementa a interface FragmentActions with the init() method and use this
private void showFragment(String fragmentTag){
FragmentTransaction trasaction = getSupportFragmentManager().beginTransaction();
FragmentActions fragment = (FragmentActions) getSupportFragmentManager().findFragmentByTag(fragmentTag);
if(fragment==null ){
if(lastFragmentviewed!=null)
trasaction.hide(lastFragmentviewed);
fragment = (FragmentActions) newInstance(fragmentTag);
trasaction.add(R.id.content_frame,(Fragment) fragment,fragmentTag);
}else{
if(lastFragmentviewed!=null && !lastFragmentviewed.equals(fragment))
trasaction.hide(lastFragmentviewed);
if(getSupportFragmentManager().findFragmentByTag(fragmentTag)!=null){
fragment.init();
trasaction.show((Fragment) fragment);
}else
trasaction.add(R.id.content_frame,(Fragment) fragment,fragmentTag);
}
lastFragmentviewed=(Fragment) fragment;
trasaction.commit();
}
Currently when running my application, going to this activity does not display my fragment. Am I adding the fragment wrong and so nothing in the fragment is displayed? Or is there something wrong the dynamic behavior in the fragment onCreateView method?
My Activity Code
public class AskQuestionActivity extends FragmentActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ask_question);
}
}
My Activity XML
<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView android:layout_width="match_parent"
android:layout_height="match_parent"
android:hint="#string/header_text"/>
<fragment android:name="com.mypackage.AskQuestionFragment"
android:id="#+id/question_fragment"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent" />
</LinearLayout>
My Fragment Code
public class AskQuestionFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
String questionText = "What is your favorite color?";
List<String> answers = Arrays.asList("Red", "Blue", "Yellow");
LinearLayout layout = (LinearLayout)inflater.inflate(R.layout.question, container);
Resources res = getResources();
int id = res.getIdentifier("question_text", "id", layout.getContext().getPackageName());
TextView questionTextView = (TextView)layout.findViewById(id);
questionTextView.setText(questionText);
id = res.getIdentifier("question_answers", "id", layout.getContext().getPackageName());
RadioGroup radioGroup = (RadioGroup)layout.findViewById(id);
Collections.reverse(answers);
for (String s : answers) {
RadioButton button = new RadioButton(layout.getContext());
button.setText(s);
radioGroup.addView(button, 0);
}
return layout;
}
}
My Fragment XML
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/question_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/question_text"/>
<RadioGroup android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/question_answers"></RadioGroup>
<Button
android:id="#+id/submit_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/submit_button_text"
/>
</LinearLayout>
try to put framelayout instead of fragment in xml. and in your activity's onCreate create the instance of your fragment you want to display and add it to the fragment container
public class AskQuestionActivity extends FragmentActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ask_question);
AskQuestionFragment fragment = new AskQuestionFragment();
getSupportFragmentManager().beginTransaction()
.add(R.id.id_of_your_container, fragment).commit();
}
}
Your problem might be when doing this:
LinearLayout layout = (LinearLayout)inflater.inflate(R.layout.question, container);
Consider to replace that line with one of the following:
LinearLayout layout = (LinearLayout)inflater.inflate(R.layout.question, null);
or
LinearLayout layout = (LinearLayout)inflater.inflate(R.layout.question, container, false);
change your layout from linear to be framelayout, and attach your fragment in activity .
getSupportFragmentManager().beginTransaction()
.add(R.id.your_fragment_container, fragment).commit();