android/App12-second/app/src/main/java/com/example/app1/MainActivity2.java

package com.example.app1;

import android.annotation.SuppressLint;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;


public class MainActivity2 extends AppCompatActivity {

    private EditText username;
    private EditText password;
    private Button login;

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

        username = findViewById(R.id.username);
        password = findViewById(R.id.password);
        login = findViewById(R.id.login);

        login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String strUsername = username.getText().toString().trim();
                String strPassword = password.getText().toString().trim();

                // 从SharedPreferences中获取保存的账号和密码
                SharedPreferences sharedPreferences = getSharedPreferences("user_mes", MODE_PRIVATE);
                String savedUsername = sharedPreferences.getString("username", "");
                String savedPassword = sharedPreferences.getString("password", "");

                if (strUsername.equals(savedUsername) && strPassword.equals(savedPassword)) {
                    Toast.makeText(MainActivity2.this, "恭喜，登录成功！", Toast.LENGTH_SHORT).show();
                    Intent intent1 = new Intent(MainActivity2.this, IndexActivity.class);
                    startActivity(intent1);
                } else {
                    Toast.makeText(MainActivity2.this, "用户名或密码错误！", Toast.LENGTH_SHORT).show();
                }

            }
        });
    }

    //点击注册按钮时，跳转到注册界面
    public void zhuce(View view) {
        Intent intent2 = new Intent(MainActivity2.this, MainActivity3.class);
        startActivity(intent2);
    }
}