Android studio按钮点击页面跳转详细步骤

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    android:gravity="center_horizontal"
    tools:context=".MainActivity">
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="用户名："/>
        <EditText
            android:id="@+id/edit1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:hint="____________"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="密码："/>
        <EditText
            android:id="@+id/edit2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:hint="____________"
            android:password="true"/>
    </LinearLayout>
    <Button
        android:id="@+id/btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="登录"/>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:background="@drawable/bg">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="40dp"
        android:textColor="#DDE0E4"
        android:text="欢迎进入智慧农业系统"
        />
</LinearLayout>

package com.example.signin;
 
import androidx.appcompat.app.AppCompatActivity;
 
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
 
public class MainActivity extends AppCompatActivity {
 
    private Button btn;
    private EditText edit1;
    private EditText edit2;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        initView();
    }
 
    private void initView() {
        btn = (Button) findViewById(R.id.btn);
        edit1 = (EditText) findViewById(R.id.edit1);
        edit2 = (EditText) findViewById(R.id.edit2);
 
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(edit1.getText().toString().equals("aaa") &&
                   edit2.getText().toString().equals("aaa")){
                    Intent intent = new Intent(MainActivity.this,nextActive.class);
                    startActivity(intent);
                }
                else {
                    Toast.makeText(MainActivity.this,"输入有误,请重新输 
                     入",Toast.LENGTH_LONG).show();
                }
            }
        });
    }
 
}