Android Studio 其他活动打不开

Question

Hi guys I've a simple problem to resolve, don't know why my code doesn't works: I have to change activity with the button pulsanteinizia but the app, when I click on pulsanteinizia crash I want to switch from to page1 (mainactivity) to page 2 clicking the button "pulsanteinizia"

How can I resolve that?

PAGE 1 (MAINACTIVITY)

package com.example.footballplayersquiz2020;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

public class page1 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button pulsanteinizia=(Button) findViewById(R.id.pulsanteinizia);
        Button pulsantenazionali=(Button) findViewById(R.id.pulsantenazionali);
        TextView record =(TextView) findViewById(R.id.record);
        TextView recordn =(TextView) findViewById(R.id.recordn);
        ImageView descrizione=(ImageView)findViewById(R.id.descrizione);
        Drawable welcome1 =getResources().getDrawable(R.drawable.welcome1);
        Drawable welcome2 =getResources().getDrawable(R.drawable.welcome2);
        Drawable welcome3 =getResources().getDrawable(R.drawable.welcome3);
        Drawable welcome4 =getResources().getDrawable(R.drawable.welcome4);

        SharedPreferences settings = getSharedPreferences("GAME_DATA", Context.MODE_PRIVATE);
        SharedPreferences settingsn = getSharedPreferences("GAME_DATAN", Context.MODE_PRIVATE);
        int highscore = settings.getInt("HIGH_SCORE", 0);
        int highscoren = settingsn.getInt("HIGH_SCOREN", 0);

        record.setText("Record: " + highscore + " punti");
        recordn.setText("Record Nazionali: " + highscoren + " punti");

        if (highscore > 0 && highscore < 30) descrizione.setImageDrawable(welcome2);
        else if (highscore >= 30 && highscore < 100) descrizione.setImageDrawable(welcome3);
        else if (highscore >= 100) descrizione.setImageDrawable(welcome4);

        pulsanteinizia.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                final Intent p2 = new Intent(getApplicationContext(),page2.class);
                startActivity(p2);
                overridePendingTransition(R.anim.enter_from_right, R.anim.exit_out_left);
                finish();
            }
        });

        pulsantenazionali.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                final String ITEM_SKU="com.nationalteams.active";
                final Intent pn = new Intent(getApplicationContext(),nationalteams.class);
                startActivity(pn);
                overridePendingTransition(R.anim.enter_from_right, R.anim.exit_out_left);
                finish();
            }
        });
    }
}

XML:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".page1">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/sfondo1"
        />


    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">


        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="top"
            android:orientation="vertical">


            <ImageView
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:id="@+id/logo2019.png"
                android:src="@drawable/logo2019"/>

            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/descrizione"
                android:src="@drawable/welcome1"/>


            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/schermo1buttons"
                android:id="@+id/pulsanteinizia"
                />

            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/schermo1buttons2"
                android:id="@+id/pulsantenazionali"/>


        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_gravity="bottom"
            android:gravity="bottom"
            android:orientation="vertical">

            <TextView
                android:layout_width="wrap_content"
                android:textColor="#FFFF00"
                android:textStyle="bold"
                android:layout_marginRight="145dp"
                android:layout_height="wrap_content"
                android:text="Record: 0 punti"
                android:id="@+id/record"/>

            <TextView
                android:textColor="#FFFF00"
                android:id="@+id/recordn"
                android:textStyle="bold"
                android:layout_marginRight="113dp"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"

                android:text="Record Nazionali: 0 punti"/>

        </LinearLayout>
    </RelativeLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

Answer 1

check if you have added page2 and nationalteams in your manifest file. If not added, add it and try.