My app crashed whenever i add a OnClickListener or a Fragment , here's my code with the OnClickListener

Question

package com.example.android.bloodapp4;

import android.content.Intent;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.widget.ArrayAdapter;

import android.widget.ListView;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ListView ourList = findViewById(R.id.theList);
        ArrayList<String> list = new ArrayList<>();
        ArrayAdapter<String> arrayAdapter = new ArrayAdapter<>(MainActivity.this , android.R.layout.simple_list_item_1,list);
        list.add("Account");
        list.add("Posts");
        list.add("Donations you made");
        ourList.setAdapter(arrayAdapter);
        ourList.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent AccIntent = new Intent(MainActivity.this, AccountActivity.class);
                startActivity(AccIntent);
            }
        });

    }
}

Answer 1

Because you don't create ArrayAdapter truly , you must create a TextView in simple_list_item_1 layout and you must add it on ArrayAdapter constructor. Say textview2 is your textview in simple_list_item_1.

 ArrayAdapter<String> arrayAdapter = new ArrayAdapter<>(MainActivity.this , android.R.layout.simple_list_item_1,textview2,list);

That will work I believe.

Answer 2

Have you declared your AccountActivity in AndroidManifest.xml?

A simple example:

<application
....>

    <activity
        android:name=".AccountActivity"/>

</application>