数据存储——SP存储

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     xmlns:tools="http://schemas.android.com/tools"
 4     android:layout_width="match_parent"
 5     android:layout_height="match_parent"
 6     android:paddingBottom="@dimen/activity_vertical_margin"
 7     android:paddingLeft="@dimen/activity_horizontal_margin"
 8     android:paddingRight="@dimen/activity_horizontal_margin"
 9     android:paddingTop="@dimen/activity_vertical_margin"
10     tools:context="com.hanqi.testapp3.MainActivity"
11     android:orientation="vertical">
12 
13     <TextView
14         android:layout_width="wrap_content"
15         android:layout_height="wrap_content"
16         android:text="Hello World!" />
17     
18     <Button
19         android:layout_width="match_parent"
20         android:layout_height="wrap_content"
21         android:text="SP存储"
22         android:onClick="bt_OnClick"/>
23 
24     <Button
25         android:layout_width="match_parent"
26         android:layout_height="wrap_content"
27         android:text="SP读取"
28         android:onClick="bt1_OnClick"/>
29 
30 </LinearLayout>

 1 package com.hanqi.testapp3;
 2 
 3 import android.content.SharedPreferences;
 4 import android.os.Bundle;
 5 import android.support.v7.app.AppCompatActivity;
 6 import android.view.View;
 7 import android.widget.Toast;
 8 
 9 public class MainActivity extends AppCompatActivity {
10 
11     @Override
12     protected void onCreate(Bundle savedInstanceState) {
13         super.onCreate(savedInstanceState);
14         setContentView(R.layout.activity_main);
15     }
16 
17     public void bt_OnClick(View v)
18     {
19         //1.得到SharedPreferences对象
20         SharedPreferences sharedPreferences=getSharedPreferences("abc",MODE_APPEND);
21 
22         //2.得到编辑器
23         SharedPreferences.Editor editor=sharedPreferences.edit();
24 
25         //3.使用editor添加数据
26 //        editor.putString("b","xxxxxx");
27 //        editor.putLong("long",123456);
28 
29         editor.remove("a");
30 
31 
32         //4.提交保存
33         editor.commit();
34 
35         Toast.makeText(MainActivity.this, "保存数据成功", Toast.LENGTH_SHORT).show();
36     }
37 
38     //读取
39     public void bt1_OnClick(View v)
40     {
41         SharedPreferences sp=getSharedPreferences("abc",MODE_PRIVATE);
42 
43         String str=sp.getString("ab", "默认值");
44 
45         Toast.makeText(MainActivity.this, "key=b"+"value="+str, Toast.LENGTH_SHORT).show();
46     }
47 }