SharedPreferences data storage

SharedPreferences

         file , analogy .properties file , Data storage uses key value pairs to store

function

         Write and read

What data can be put into SharedPreferences？

         Original basic data , Composite data is not allowed

        boolean float int long String

How to get SharedPreferences？

    SharedPreferences sp = getSharedPreferences( Parameters 1, Parameters 2)   Parameters 1： Storage file name   Parameters          MODE_PRIVATE  Pattern 

The process of writing ？

// 1  obtain SharedPreferences

SharedPreferences sp=getSharedPreferences("loginfo",MODE_PRIVATE);

// 2  With the help of Editor

 SharedPreferences.Editor edit = sp.edit();

// 3  Write data 

edit.putString("user",user);
edit.putString("pwd",pwd);

// 4  Submit data 

 edit.commit();

The process of reading ？

// 1  obtain SharedPreferences

SharedPreferences sp=getSharedPreferences("loginfo",MODE_PRIVATE);

// 2  according to key To get the value 

String user1 = sp.getString("user", "");
String pwd1 = sp.getString("pwd", "");

Case study ： The login function of account and password can be backfilled

1.java file

 2.xml file