package fry;

 import com.example.rememberUserAndPassword.R;

 import android.app.Activity;

 import android.content.SharedPreferences;

 import android.content.SharedPreferences.Editor;

 import android.os.Bundle;

 import android.view.View;

 import android.widget.Button;

 import android.widget.CheckBox;

 import android.widget.TextView;

 import android.widget.Toast;

 public class Activity01 extends Activity{

     private Button btn_login;

     private TextView et_username;

     private TextView et_password;

     private CheckBox cb_choose;

     private SharedPreferences config;

     @Override

     protected void onCreate(Bundle savedInstanceState) {

         // TODO Auto-generated method stub

         super.onCreate(savedInstanceState);

         setContentView(R.layout.activity01);

         config=getSharedPreferences("config", MODE_PRIVATE);

         btn_login=(Button) findViewById(R.id.btn_login);

         et_username=(TextView) findViewById(R.id.et_username);

         et_password=(TextView) findViewById(R.id.et_password);

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

         //是否记住了密码，初始化为false

         boolean isCheck=config.getBoolean("isCheck", false);

         //Toast.makeText(this, isCheck+" ", Toast.LENGTH_SHORT).show();

         if(isCheck){

             et_username.setText(config.getString("username", ""));

             et_password.setText(config.getString("password", ""));

             cb_choose.setChecked(isCheck);

         }

     }

     //权限要是public,要不然访问不到

     //因为在button控件中设置了android:onClick="onClick"

     public void onClick(View view){

         Toast.makeText(this, "登录成功", Toast.LENGTH_SHORT).show();

         Editor edit=config.edit();

         String username=et_username.getText().toString();

         String password=et_password.getText().toString();

         boolean isCheck=cb_choose.isChecked();

         //Toast.makeText(this, isCheck+" ", Toast.LENGTH_SHORT).show();

         //存储CheckBox的状态

         edit.putBoolean("isCheck", isCheck);

         if(isCheck){

             edit.putString("username", username).putString("password", password);

         }else{

             edit.remove("username").remove("password");

         }

         //提交到本地

         edit.commit();

     }

 }

 <?xml version="1.0" encoding="utf-8"?>

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

     android:layout_width="match_parent"

     android:layout_height="match_parent"

     android:orientation="vertical" >

     <EditText

         android:id="@+id/et_username"

         android:layout_width="match_parent"

         android:layout_height="wrap_content"

         />

     <EditText

         android:id="@+id/et_password"

         android:layout_width="match_parent"

         android:layout_height="wrap_content"

         android:ems="10" >

         <requestFocus />

     </EditText>

     <LinearLayout

         android:layout_width="wrap_content"

         android:layout_height="wrap_content"

         >

         <CheckBox

                 android:id="@+id/cb_choose"

             android:layout_width="wrap_content"

             android:layout_height="wrap_content"

             />

         <TextView

             android:layout_width="wrap_content"

             android:layout_height="wrap_content"

             android:text="记住密码"

             />

     </LinearLayout>

     <!-- android:onClick="onClick" 点击时去class中调用onClick方法，权限要为public -->

     <Button

         android:id="@+id/btn_login"

         android:layout_width="wrap_content"

         android:layout_height="wrap_content"

         android:text="登录"

         android:layout_gravity="center_horizontal"

         android:onClick="onClick"

         />

 </LinearLayout>