SharedPreferences存储

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.hanqi.testapp3.MainActivity"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="sp存储"
        android:onClick="bt_OnClick"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="sp读取"
        android:onClick="bt1_OnClick"/>
</LinearLayout>

package com.hanqi.testapp3;

import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

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

    public void bt_OnClick(View v)
    {
        //1、得到SharedPreferences对象
        SharedPreferences sharedPreferences = getSharedPreferences("abc", MODE_APPEND);

        //2、得到编辑器
        SharedPreferences.Editor editor = sharedPreferences.edit();

        //3、使用Editor添加数据
//        editor.putString("b","xxxxxx");
//        editor.putLong("long",123456);

        //移除数据
        editor.remove("a");

        //4、提交保存
        editor.commit();

        Toast.makeText(MainActivity.this, "保存数据成功", Toast.LENGTH_SHORT).show();
    }

    public void bt1_OnClick(View v)
    {
        SharedPreferences sp = getSharedPreferences("abc",MODE_PRIVATE);

        String str = sp.getString("b", "默认值");

        Toast.makeText(MainActivity.this, "key = b" + " value = " + str, Toast.LENGTH_SHORT).show();
    }
}