SharedPreferences存储

SharePreferences是使用键值对的方式来存储数据的。

实例

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

   <EditText
       android:id="@+id/edit_text"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"/>
   <TextView
       android:id="@+id/text_view"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"/>
   <Button
       android:text="存储"
       android:id="@+id/button"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"/>

   <Button
       android:text="读取"
       android:id="@+id/button_read"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"/>
</LinearLayout>

package com.example.myadroid;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.ActionMode;
import android.view.ContextMenu;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.PopupMenu;
import android.widget.TextView;
import android.widget.Toast;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button button = findViewById(R.id.button);
        Button button1 = findViewById(R.id.button_read);
        final EditText editText = findViewById(R.id.edit_text);
        final TextView textView = findViewById(R.id.text_view);

        //存储
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SharedPreferences.Editor editor = getSharedPreferences("data",MODE_PRIVATE).edit();
                editor.putString("name","Tom");
                editor.putInt("age",28);
                editor.putBoolean("married",false);
                editor.apply();
            }
        });

        //读取
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SharedPreferences pref = getSharedPreferences("data",MODE_PRIVATE);
                //第一个参数是键,第二个是默认值
                String name = pref.getString("name","");
                int age = pref.getInt("age",0);
                boolean married = pref.getBoolean("married",true);
                textView.setText(name+" "+age+" "+married);

            }
        });
    }

}