Listview not working for Android Studio

Question

I'm trying to create a listView for lecturers in my faculty. There's something wrong, the app don't work, and the preview shows the default listView.

my xml code is:

<?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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
>

<ListView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/listView">

</ListView>
</RelativeLayout>

And my java code is:

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.util.ArrayList;

class lectures extends AppCompatActivity {
ListView ListView2;
ArrayAdapter<String> adapter;
public static String[] names = {"Dr.Aiad","Mr.Hamed","Mr.Qahtan","Dr.reza","Mr.Osamah",};


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ListView2 = (ListView)findViewById(R.id.listview);
    adapter = new ArrayAdapter<String>(this, android.R.layout.activity_list_item, names);
    ListView2.setAdapter(adapter);

}
}

Answer 1

Replace your code with this :)

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.util.ArrayList;

class lectures extends AppCompatActivity {
ListView listView2;
ArrayAdapter<String> adapter;
 String[] names = {"Dr.Aiad","Mr.Hamed","Mr.Qahtan","Dr.reza","Mr.Osamah"};


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    listView2 = (ListView)findViewById(R.id.listview);
    adapter = new ArrayAdapter<String>(this, R.layout.activity_list_item, names);
    listView2.setAdapter(adapter);

 }
}

Hope it helps you!! :)

Answer 2

try like this listview = (ListView) findViewById(R.id.listView); String[] values = new String[] { "Red Color", "Blue Color", "Green Color", "Yellow Color", "Violet Color", "Purple Color" };

    ArrayAdapter adapter = new ArrayAdapter(this,
        android.R.layout.simple_list_item_1,
        android.R.id.text1, values);

    listview.setAdapter(adapter);

    listview.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView parent, View view,
                int position, long id) {


            String itemValue = (String) listview
                    .getItemAtPosition(position);


    Toast.makeText(getApplicationContext(),
        "Selected  " + itemValue, Toast.LENGTH_LONG).show();

        }

    });

may refer--> http://androidcoding.in/2016/04/24/android-tutorial-on-listview/