安卓SharedPreferences的使用

package com.contentprovide.liuliu.shard;

import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {


    Button save_btn,get_btn;
    EditText et;
    TextView tv;


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

        save_btn = (Button) findViewById(R.id.save_btn);
        get_btn = (Button) findViewById(R.id.get_btn);
        et = (EditText) findViewById(R.id.et);
        tv = (TextView) findViewById(R.id.tv);


        save_btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
//                获取输入框里的内容
                String s = et.getText().toString();
//                获取sharedPreferences对象
                SharedPreferences sharedPreferences = MainActivity.this.getSharedPreferences("Myshard",MainActivity.this.MODE_PRIVATE);
//                通过Editor对象对数据进行操作
                SharedPreferences.Editor editor = sharedPreferences.edit();
                editor.putString("usename",s);
                editor.commit();
            }
        });

        get_btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String s = "";
                SharedPreferences sharedPreferences = MainActivity.this.getSharedPreferences("Myshard",MainActivity.this.MODE_PRIVATE);
//                获取数据因为不需要对数据进行更改，所以不需要Editor对象，可以用sharedPreferences进行获取
                s = sharedPreferences.getString("usename","默认数据");
                tv.setText(s);
            }
        });


    }
}