安卓SharedPreferences类的使用

 package com.lidaochen.phonecall;

 import android.content.Intent;

 import android.content.SharedPreferences;

 import android.net.Uri;

 import android.os.Environment;

 import android.support.v7.app.AppCompatActivity;

 import android.os.Bundle;

 import android.text.TextUtils;

 import android.util.Log;

 import android.view.View;

 import android.widget.Button;

 import android.widget.CheckBox;

 import android.widget.EditText;

 import android.widget.TabHost;

 import android.widget.ThemedSpinnerAdapter;

 import android.widget.Toast;

 import java.util.Map;

 public class MainActivity extends AppCompatActivity{

     private EditText et_userName;

     private EditText et_pwd;

     private CheckBox cb;

     private SharedPreferences sp;

     @Override

     protected void onCreate(Bundle savedInstanceState) {

         super.onCreate(savedInstanceState);

         setContentView(R.layout.activity_main);

         // 初始化sp实例

         sp = getSharedPreferences("test", 0);

         // 1.获取控件

         et_userName = (EditText)findViewById(R.id.et_username);

         et_pwd = (EditText)findViewById(R.id.et_pwd);

         cb = (CheckBox)findViewById(R.id.cb);

         // 把我们需要的数据在test.xml中显示出来，然后在控件上显示出来

         String name = sp.getString("name", "");

         String pwd = sp.getString("pwd", "");

         // 将数据显示在控件上

         et_userName.setText(name);

         et_pwd.setText(pwd);

     }

     // 按钮点击事件

     public void login(View v)

     {

         // 获取userName和pwd

         String name = et_userName.getText().toString().trim();

         String pwd = et_pwd.getText().toString().trim();

         // 判断name和pwd是否为空

         if(TextUtils.isEmpty(name) || TextUtils.isEmpty(pwd))

         {

             Toast.makeText(MainActivity.this, "用户名或密码不能为空", Toast.LENGTH_LONG).show();

         }

         else

         {

             System.out.println("登录之后要干的事情！");

             if(cb.isChecked())

             {

                // 获取sp的编辑器

                 SharedPreferences.Editor edit = sp.edit();

                 edit.putString("name", name);

                 edit.putString("pwd", pwd);

                 // 把edit进行提交

                 edit.commit();

                 Toast.makeText(MainActivity.this, "保存成功！", Toast.LENGTH_LONG).show();

             }

             else

             {

                 Toast.makeText(MainActivity.this, "请勾选复选框", Toast.LENGTH_LONG).show();

             }

         }

     }

 }