This question already has answers here:
Your content must have a ListView whose id attribute is 'android.R.id.list'
(7 answers)
Closed 8 years ago.
I am new to Android. when I run my project, I got the following error:
Your content must have a ListView whose id attribute is 'android.R.id.list'
it crush on this line:
setContentView(R.layout.activity_main);
my activity_main.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="com.soft8.sql_test.MainActivity" >
<ListView
android:id="#+id/TheClient"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
</ListView>
</RelativeLayout>
and main class:
public class MainActivity extends ListActivity {
private ArrayList results = new ArrayList();
SQLController dbcon;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final ListView lv1 = (ListView) findViewById(R.id.TheClient);
dbcon = new SQLController(this);
dbcon.open();
dbcon.insertSomeItmes();
results = (ArrayList) dbcon.ReadData();
lv1.setAdapter(new CustomListAdapter(this, results));
dbcon.close();
}
Thank you.
Change this
android:id="#+id/TheClient"
to
android:id="#android:id/list"
There is no need to ListView Cast it because already extends your Activity with ListActivity
and also remove
final ListView lv1 = (ListView) findViewById(R.id.TheClient);
and directly set adapter by using
setListAdapter(new CustomListAdapter(this, results));
When you extend your activity from ListActivity, you don't need to define your list again.
The ListActivity automatically looks in the layout set for it for a ListView with id "list". If it does not find a ListView with id "list" it gives your error.
So change
android:id="#+id/TheClient"
to
android:id="#android:id/list"
and remove definition of your list from activity. (remove findViewById line)
Or just extend normal Activity instead of ListActivity.
One potential error will come from the fact that you use upper case in your id
android:id="#+id/TheClient"
try with lower case
android:id="#+id/the_client"
Rename the id of your ListView
android:id="#+id/TheClient"
to
android:id="#android:id/list"
Since you are using ListActivity your xml file must specify the keyword android while mentioning to a ID
and remove
final ListView lv1 = (ListView) findViewById(R.id.TheClient);
from activity code.
i.e. simply rewrite your code as
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dbcon = new SQLController(this);
dbcon.open();
dbcon.insertSomeItmes();
results = (ArrayList) dbcon.ReadData();
setAdapter(new CustomListAdapter(this, results));
dbcon.close();
}
Related
This question already has answers here:
AndroidStudio Cannot Find Layout
(2 answers)
Closed 2 years ago.
I am using Android Studio. I am currently trying to make a custom adapter and I have been having trouble with my .xml files. Although I have created them and added the content I would like to see in them, when I call for them in the main activity Java file, I get an error saying it does not exist. Additionally, the SetOnItemClickListener and setAdapter will not work. None of my other files show any sort of errors.
.xml I would like to show, titled characteritem_layout:
<?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">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/detail_name"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/detail_status"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/detail_explanation"/>
</LinearLayout>
My code for the main activity:
package com.example.app.activities;
import ...
public class MainActivity extends AppCompatActivity {
private Button denButton;
private Button sweButton;
private Button aboutButton;
private TextView welcome;
private ArrayList<CharacterItem> characters;
private ListView charList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setContentView(R.layout.characteritem_layout)
welcome = findViewById(R.id.welcome_screen);
//The other buttons work perfectly well.
initializeList();
final CharacterAdapter charAdapter = new CharacterAdapter(this, R.layout.characteritem_layout, characters);
characters.setAdapter(charAdapter);
characters.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent intent = new Intent(getApplicationContext(), CharacterActivity.class);
intent.putExtra("charItem", characters.get(position));
startActivity(intent);
}
});
private void initializeList(){
characters = new ArrayList<CharacterItem>();
characters.add(new CharacterItem("Finland", false, "Not in progress yet"));
characters.add(new CharacterItem("Norway", true, "Getting the Viking trio in first!"));
characters.add(new CharacterItem("Iceland",false,"He's next!"));
}
}
first of all, to use setContentView twice will not be working in way you want
in my case, right click layout folder and then chose new Layout Resource file works
I know that this question has been asked a lot of times already but I have went to all of the answers and none of them worked for me.
So, issue with the App is that I am trying to populate an ArrayList into a ListView using an ArrayAdapter and the app MainActivity doesn't show anything but white screen when launched.
Here's
MainActivity.java
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public static class PlaceholderFragment extends Fragment{
private ArrayAdapter<String> mForecastAdapter;
public PlaceholderFragment(){}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
//Inflate the layout for this fragment
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
String[] forecastArray = {
"Today - Sunny - 88/63",
"Tomorrow - Foggy - 70/46",
"Weds - Cloudy - 72/63",
"Thurs - Rainy - 64/51",
"Fri - Foggy - 70/46",
"Sat - Sunny - 76/68"
};
List<String> weekForecast = new ArrayList<String>(Arrays.asList(forecastArray));
ListView listView = (ListView) rootView.findViewById(R.id.listview_forecast);
listView.setAdapter(mForecastAdapter);
mForecastAdapter = new ArrayAdapter<String>(
//The current context (current activity)
getActivity(),
//ID of list item layout
R.layout.list_item_forecast,
//id of the textView to populate
R.id.list_item_forecast_textview,
//data to populate
weekForecast
);
return rootView;
}
}
fragment_main.xml
<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"
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.gautamhans.sunshine.app.MainActivityFragment"
tools:showIn="#layout/activity_main">
<ListView
android:id="#+id/listview_forecast"
android:layout_width="match_parent"
android:layout_height="667dp"
/>
</FrameLayout>
Here's list_item_forecast.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"
android:minHeight="?android:attr/listPreferredItemHeight"
android:gravity="center_vertical"
android:id="#+id/list_item_forecast_textview"
>
</TextView>
Of course the activity is not showing anything, you're not placing the fragment inside your activity! Use this in your activity's onCreate():
getSupportFragmentManager().beginTransaction()
.replace(R.id.container, new PlaceholderFragment(), "fragment_tag").commit();
Where R.id.container is a layout inside your main_activity_layout file (empty layout)
UPDATE:
have these 2 file:
activity_main:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
</RelativeLayout>
fragment_main:
<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"
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.gautamhans.sunshine.app.MainActivityFragment"
tools:showIn="#layout/activity_main">
<ListView
android:id="#+id/listview_forecast"
android:layout_width="match_parent"
android:layout_height="667dp"
/>
</FrameLayout>
keep the 3° layout file, it's ok.
Now, in your activity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getSupportFragmentManager().beginTransaction()
.replace(R.id.container, new PlaceholderFragment(), "fragment_tag").commit();
}
also:
mForecastAdapter = new ArrayAdapter<String>(
//The current context (current activity)
getActivity(),
//ID of list item layout
R.layout.list_item_forecast,
//id of the textView to populate
R.id.list_item_forecast_textview,
//data to populate
weekForecast
);
//move this after the initialization of adapter
listView.setAdapter(mForecastAdapter);
When you set the ListView adapter,the adapter's reference is null and you set the null adapter for ListView.You should create the adapter before set ListView adapter.
ListView listView = (ListView) rootView.findViewById(R.id.listview_forecast);
mForecastAdapter = new ArrayAdapter<String>(
//The current context (current activity)
getActivity(),
//ID of list item layout
R.layout.list_item_forecast,
//id of the textView to populate
R.id.list_item_forecast_textview,
//data to populate
weekForecast
);
listView.setAdapter(mForecastAdapter);
Is your PlaceHolderFragment within your MainActivity.java file?
If so, try separating it on its own file PlaceHolderFragment.java..
As far as I know, java only allows one public class per source file.. That maybe the reason of your problem..
I have 2 xml file
MainActivity.xml
2.Example.xml
I have listview in Example.xml.the code I have written in Example.java. But the data is not displaying in listview..Kindly go through my code
Example.xml
<?xml version="1.0" encoding="utf-8"?>
<ViewSwitcher xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/profileSwitcher"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ListView
android:id="#+id/listPasscode"
android:layout_height="wrap_content"
android:layout_width="match_parent">
</ListView>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Test"/>
</LinearLayout>
</ViewSwitcher>
Example.java
public class ListViewAndroidExample extends Activity {
ListView listView ;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
listView = (ListView) findViewById(R.id.listPasscode);
// Define a new Adapter
// First parameter - Context
// Second parameter - Layout for the row
// Third parameter - ID of the TextView to which the data is written
// Forth - the Array of data
// Array of strings...
String[] countryArray = {"India", "Pakistan", "USA", "UK"};
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, android.R.id.text1, countryArray);
// Assign adapter to ListView
listView.setAdapter(adapter);
setContentView(R.layout.activity_list_view_android_example);
}
}
Is linking between xml and java file right ?If not suggest me
Try this..
Add setContentView before initializing the ListView
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list_view_android_example);
listView = (ListView) findViewById(R.id.listPasscode);
EDIT
Change this..
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, android.R.id.text1, countryArray);
to
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, countryArray);
I am working on a first basic android app as a university project and I have an array list of names. I want it to be put into a ListView. The problem I have is nothing appears when I bring in the ListViewunder the xml document. I don't get the basic template for item1, sub item 1 etc.
Then when I set up the array to play in the list view still empty list. Below I have the xml document
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ListView
android:layout_width="wrap_content"
android:layout_height="277dp"
android:id="#+id/listView" android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" android:layout_marginTop="7dp"
android:layout_alignParentBottom="true"/>
</RelativeLayout>
then here is the java code:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
populateListView();
}
private void populateListView() {
String[] myItems = {"frank","george","alice", "anna"};
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.main, myItems);
ListView list = (ListView)findViewById(R.id.listView);
list.setAdapter(adapter);
}
Your problem is that you have the same layout R.layout.main for two different use.
You set the content view as setContentView(R.layout.main); where your ListView is but you also use this layout with your adapter as new ArrayAdapter<String>(this, R.layout.main, myItems);.
So with your code, you don't have any item layout to display your array myItems. You need to create another layout as R.layout.item_layout with a TextView inside (or use an android layout like android.R.layout.simple_list_item_1) for your adapter.
Note: to avoid some bugs with ListView, you have also to set the height to match_parent or fill_parent
Try this for your adapter:
ArrayAdapter<String> adapter=
new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, myItems);
The adapter has to inflate a TextView. You can make your own TextView (if you want to customize it) in XML.
Then it will be:
ArrayAdapter<String> adapter=
new ArrayAdapter<String>(this, R.layout.yourcustomtextview, myItems);
The default array adapter in Android takes the layout for the row as the second argument.
Change your ArrayAdapter constructor to something like this:
ArrayAdapter<String> adapt = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, items)
I found the template that ADT generates for a Master/Detail Flow Activity to be rather obtuse, and I don't like the fact that the ListView is not declared in a layout file which forces me to work with it programatically. For example, instead of just setting android:background on the ListView in a layout file, I'm forced to find the ListView via findViewById in the fragment's onCreateView(...) method, then call setBackground(...). For maintainability and general readability, I'd like to do the same thing via a layout file.
Instead, I'm trying to inflate a custom layout in the onCreateView method of the "master" fragment:
public class InboxFragment extends ListFragment {
public InboxFragment() {}
private ListView listView = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
listView = (ListView) inflater.inflate(R.layout.inbox_fragment_layout,
null);
return listView;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
// the following doesn't work
listView.setAdapter(new ArrayAdapter<DummyContent.DummyItem>(getActivity(),
android.R.layout.simple_list_item_activated_1,
android.R.id.text1,
DummyContent.ITEMS));
// nor does this
//setListAdapter(new ArrayAdapter<DummyContent.DummyItem>(getActivity(),
// android.R.layout.simple_list_item_activated_1,
// android.R.id.text1,
// DummyContent.ITEMS));
}
}
However, calling setListAdapter (or even setAdapter) doesn't seem to do anything, even though I've given the ListView an id of android:id="#id/android:list" in R.layout.inbox_fragment_layout:
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#id/android:list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#D3D3D3" />
My "master" activity just calls a fragment layout:
public class InboxActivity extends FragmentActivity {
#Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.inbox_phone_layout);
}
}
inbox_phone_layout.xml:
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragmentPhoneInbox"
android:name="com.justin.inbox.InboxFragment"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1" />
Instead, I'm greeted with a blank page and it doesn't look like the ListView is loaded at all. What am I doing wrong, here? Sample project on GitHub.
I fixed your issue by changing inbox_phone_layout.xml to the following:
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragmentPhoneInbox"
android:name="com.justin.inbox.InboxFragment"
android:layout_width="match_parent"
android:layout_height="match_parent" />