Android的存储 SharedPreferences和SQLite数据库

 

 

 

package com.zlj.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.content.SharedPreferences;
import android.os.Bundle;
import android.widget.Toast;

public class MainActivity4 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main4);
        //数据的存储
        //模拟登录是记录账号密码功能
        String user = "root";
        String pwd = "123456";
        //数据的写入
        //1. 获取SharedPreferences
        SharedPreferences sp = getSharedPreferences("loginfo",MODE_PRIVATE);
        //2.借助Editor，向SharedPreferences中写入数据
        SharedPreferences.Editor editor = sp.edit();
        //3.写入数据 只能写入原始基本数据类型，不能写入复合型数据
        editor.putString("user",user);
        editor.putString("pwd",pwd);
        //4.提交数据
        editor.commit();

        //数据的读取
        //1.获取SharedPreferences
        SharedPreferences sp1 = getSharedPreferences("loginfo",MODE_PRIVATE);
        //2.获取数据
       String sp_user = sp.getString("user","");
        String sp_pwd =  sp.getString("pwd","");
        Toast.makeText(this, "账号："+sp_user+"密码:"+sp_pwd, Toast.LENGTH_SHORT).show();
    }
}