mobileDev/app/src/main/java/com/demo/logining/MainActivity.java

package com.demo.logining;

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 {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        EditText Accm = findViewById(R.id.accM);
        EditText Pswm = findViewById(R.id.pasM);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button button1 = findViewById(R.id.button1);
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(!Register1Activity.isRegister)
                    Toast.makeText(MainActivity.this,"账号不存在，请先注册",Toast.LENGTH_LONG).show();
                else {
                    Toast.makeText(MainActivity.this, "登录成功！！！", Toast.LENGTH_LONG).show();
                    Intent i = new Intent(MainActivity.this, MyInfor1Activity.class);
                    startActivity(i);
                }
            }
        });

//        if(Register1Activity.isRegister){
//            Intent intent=this.getIntent();
//            Bundle bundle=intent.getExtras();
//            String acc = bundle.getString("acc");
//            String psw = bundle.getString("password");
//            Accm.setText(acc);
//            Pswm.setText(psw);
//        }

        Button button2 = findViewById(R.id.button2);
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent i =new Intent(MainActivity.this,Register1Activity.class);
                startActivity(i);
            }
        });
    }
}