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How to set an ArrayAdapter to a String Array using the resource id (R.string.)

I tried to cast the returned value from the resource into a string but it doesn't work.
this is my code:
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class MainActivity extends AppCompatActivity {
String[] storiesTitles = {(String) getText(R.string.first_story_title), (String) getText(R.string.second_story_title), (String) getText(R.string.third_story_title)};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ArrayAdapter adapter = new ArrayAdapter(MainActivity.this, android.R.layout.simple_expandable_list_item_1, storiesTitles);
ListView list = findViewById(R.id.lv_stories);
list.setAdapter(adapter);
}
}

You can refer to this link:
Android documentation: string resources
And this is the solution you are looking for:
Resources res = getResources();
String[] planets = res.getStringArray(R.array.planets_array);
The 'planets' array will contains all the string you defined for it in the strings.xml

Call the string array inside onCreate function
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String[] storiesTitles = {(String) getText(R.string.first_story_title), (String) getText(R.string.second_story_title), (String) getText(R.string.third_story_title)};
ArrayAdapter adapter = new ArrayAdapter(MainActivity.this, android.R.layout.simple_expandable_list_item_1, storiesTitles);
ListView list = findViewById(R.id.lv_stories);
list.setAdapter(adapter);
}
}

You probably get this:
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.myniprojects.testsave/com.myniprojects.testsave.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference
You have to init array in onCreate like this:
public class MainActivity extends AppCompatActivity
{
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String[] storiesTitles = {(String) getText(R.string.first_story_title), (String) getText(R.string.second_story_title), (String) getText(
R.string.third_story_title)};
ArrayAdapter adapter = new ArrayAdapter(MainActivity.this,
android.R.layout.simple_expandable_list_item_1,
storiesTitles
);
ListView list = findViewById(R.id.lv_stories);
list.setAdapter(adapter);
}
}
Now it should work. But easier way is to make this like that:
in res/values/strings.xml add:
<string-array name="titles_array">
<item>First title</item>
<item>Second title</item>
<item>Third title</item>
</string-array>
And MainActivity:
public class MainActivity extends AppCompatActivity
{
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String[] storiesTitles = getResources().getStringArray(R.array.titles_array);
ArrayAdapter<String> adapter = new ArrayAdapter<>(MainActivity.this,
android.R.layout.simple_expandable_list_item_1,
storiesTitles
);
ListView list = findViewById(R.id.lv_stories);
list.setAdapter(adapter);
}
}

Android studio , List View, java

The app is keeps crashing , what can I do?
this is the code:
#Override
protected void onCreate(Bundle savedInstanceState) {
ListView TestListView = findViewById(R.id.ListView1);
final ArrayList<String> TestObjects = new ArrayList<String>(asList("PC" , "Phone"));
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this , android.R.layout.simple_list_item_1,TestObjects);
TestListView.setAdapter(arrayAdapter);
}
}

this is my code,it can work.
String[] Balls= new String[] {"ball","pen","toy","other"};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ex_list_view01);
lstPrefer=(ListView) findViewById(R.id.lstPrefer);
ArrayAdapter<String> adapterBalls=new ArrayAdapter<String>(
this,android.R.layout.simple_list_item_1,Balls);
lstPrefer.setAdapter(adapterBalls);
lstPrefer.setOnItemClickListener(lstPreferListener);
}

Array adapter and ListView Showing wrong data

I am trying multiple activities that obtain data from ArrayLists. I have written the layout files and the java files but now one of the activities is showing the ArrayList from another activity.
There is no error so I am not quite sure what I am doing wrong.
The first array and adapter:
public class AlbumsActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_albums);
ArrayList<String> albums = new ArrayList<>();
albums.add("Umqele");
albums.add("We are friends");
albums.add("Isiphithiphiti");
albums.add("Scorpion kings");
albums.add("Red");
albums.add("Different world");
albums.add("Irue");
albums.add("Dirty Computer");
albums.add("Anti");
albums.add("Love Girls");
ArrayAdapter<String> albumsAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, albums);
ListView albumView = findViewById(R.id.albums);
albumView.setAdapter(albumsAdapter);
}
The second:
public class PlaylistActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_playlists);
ArrayList<String> lists = new ArrayList<>();
lists.add("House");
lists.add("MorningJams");
lists.add("SundayTunes");
ArrayAdapter<String> listAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, lists);
ListView listView = findViewById(R.id.playlist);
listView.setAdapter(listAdapter);
}

Here is the output of your code. It runs as expected. Meaning different data in each Activity.
MainActivity
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String a[] = new String[4];
playlist = findViewById(R.id.open_playlist_bt);
album = findViewById(R.id.open_albumlist_bt);
playlist.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivity(new Intent(MainActivity.this, PlaylistActivity.class));
}
});
album.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivity(new Intent(MainActivity.this, AlbumsActivity.class));
}
});
}
AlbumsActivity
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String a[] = new String[4];
ArrayList<String> albums = new ArrayList<>();
albums.add("Umqele");
albums.add("We are friends");
albums.add("Isiphithiphiti");
albums.add("Scorpion kings");
albums.add("Red");
albums.add("Different world");
albums.add("Irue");
albums.add("Dirty Computer");
albums.add("Anti");
albums.add("Love Girls");
ArrayAdapter<String> albumsAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, albums);
ListView albumView = findViewById(R.id.album);
albumView.setAdapter(albumsAdapter);
}
public void openPlasylistActivity(View view) {
startActivity(new Intent(this, PlaylistActivity.class));
}
Playlist Activity
public class PlaylistActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
ArrayList<String> lists = new ArrayList<>();
lists.add("House");
lists.add("MorningJams");
lists.add("SundayTunes");
ArrayAdapter<String> listAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, lists);
ListView listView = findViewById(R.id.play_list);
listView.setAdapter(listAdapter);
}
}

Show the text from EditText on ListView

I have a button, an editText, and a listView on my project. The function I want to realize is that as I enter some words in editText and click the button, the words I typed need to be in the listView.
Here is my code. After debugging, it shows error: incompatible types: String cannot be converted to String[]
public class MainActivity extends AppCompatActivity {
private String[] str = new String[10];
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = (ListView) findViewById(R.id.list_view); //build listview
ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, str);
listView.setAdapter(adapter);
}
public void sendMessage(View view){
EditText editText = (EditText) findViewById(R.id.editText);
str = editText.getText().toString();
}
}

Below is working code for what you want.
step 1 -> Add data in edit text
step 2 -> click on submit button
step 3 -> Added data will display in listview
public class MainActivity extends AppCompatActivity {
private List<String> str = new ArrayList<>();
private ArrayAdapter adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = findViewById(R.id.list_view); //build listview
adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, str);
listView.setAdapter(adapter);
}
public void sendMessage(View view) {
EditText editText = findViewById(R.id.editText);
str.add(editText.getText().toString());
adapter.notifyDataSetChanged();
editText.setText("");
}
}

Try it this way
public class MainActivity extends AppCompatActivity {
private List<String> str = new ArrayList<String>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = (ListView) findViewById(R.id.list_view); //build listview
ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, str);
listView.setAdapter(adapter);
}
public void sendMessage(View view){
EditText editText = (EditText) findViewById(R.id.editText);
String str1 = editText.getText().toString();
str.add(str1);
}
}

error error: incompatible types: String cannot be converted to String[]
is because of str = editText.getText().toString();
here you are trying to assign string to array of string incorrectly
what you have to do is use ArrayList insted of String[] as it is dynamic and efficient than String[]
and
insted of str = editText.getText().toString(); do
arrayList.add(ditText.getText().toString());

In your case you are using String[] array with size 10.
now if you want to add string from EditText in ListView then you have to add like below.
public class MainActivity extends AppCompatActivity {
private String[] str = new String[10];
int count = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = (ListView) findViewById(R.id.list_view); //build listview
ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, str);
listView.setAdapter(adapter);
}
public void sendMessage(View view){
EditText editText = (EditText) findViewById(R.id.editText);
if(count < str.length){
str[count] = editText.getText().toString();
count++;
}
}
}
Why you geeting error?
You get the error because you set the String array as a string. But if you want to add string in string array then you have to specify a position for array.

Cannot resolve constructor in ArrayAdapter

public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
EditText myeditText1;
EditText myeditText2;
Button myButton;
Double myfirstET1;
Double myfirstET2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
myeditText1 = (EditText) findViewById(R.id.editText1);
myeditText2 = (EditText) findViewById(R.id.editText2);
myButton = (Button) findViewById(R.id.buttonID);
final TextView myTextView = (TextView) findViewById(R.id.textView2);
myButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
myfirstET1 = Double.parseDouble(myeditText1.getText().toString());
myfirstET2 = Double.parseDouble(myeditText2.getText().toString());
final ListView mListView = (ListView) findViewById(R.id.mList);
if ((myeditText1.getText().length() > 0) && (myeditText2.getText().length() > 0)) {
double oper1 = Double.parseDouble(myeditText1.getText().toString());
double oper2 = Double.parseDouble(myeditText2.getText().toString());
double result = oper1 / oper2;
myTextView.setText(Double.toString(result));
Double myyList[] = {oper1, oper2 + 1, oper2 + 1};
ListAdapter myAdapter = new ArrayAdapter<Double>(this, android.R.layout.simple_list_item_1, myyList);
mListView.setAdapter(myAdapter);
}
}
});
Upon creating the ListView and setting adapter to it, I'm getting error in ListAdapter.. How do I fix it OR whats the easy alternative for it?
I hope my moto is clear with the code I've written.
All suggestions are heartly appreciated.

You need to use MainActivity.this instead of this in anonymous class to refer to this actual Activity context as
ListAdapter myAdapter = new ArrayAdapter<Double>(MainActivity.this, android.R.layout.simple_list_item_1, myyList);
// ^^^^^^^^^^^^^^^^^^
and also mention the type and use ArrayAdapter not ListAdapter
ArrayAdapter<Double> myAdapter = new ArrayAdapter<>(MainActivity.this...);
// ^^^^^^^

you should use something like this
ArrayAdapter<Double> myAdapter = new ArrayAdapter<Double>(this, android.R.layout.simple_list_item_1, myyList);

You can either use
ListAdapter myAdapter = new ArrayAdapter<>(MainActivity.this,
android.R.layout.simple_list_item_1, myyList);
mListView.setAdapter(myAdapter);
or
ListAdapter myAdapter = new ArrayAdapter<Double>(MainActivity.this,
android.R.layout.simple_list_item_1, myyList);
mListView.setAdapter(myAdapter);
But make sure instead of this use MainActivity.this