数据保存与提取
package com.sky;import android.app.Activity;import android.os.Bundle;import android.content.SharedPreferences;import android.widget.EditText;public class saveData extends Activity { /** Called when the activity is first created. */ public static final String SETTING_INFOS = "SETTING_Infos";public static final String NAME = "NAME";public static final String PASSWORD = "PASSWORD";private EditText field_name;//接收用户名的组件 private EditText filed_pass;//接收密码的组件 @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); field_name = (EditText) findViewById(R.id.EditText01);//首先获取用来输入用户名的组件 filed_pass = (EditText) findViewById(R.id.EditText02); //同时也需要获取输入密码 // Restore preferences //获取一个SharedPreferences对象,SETTING_INFOS与SETTING_INFOS.XML文件相对应 //效果相当于读取SETTING_INFOS.XML文件,如果文件不存在,则进行创建 SharedPreferences settings = getSharedPreferences(SETTING_INFOS, 0); //取出保存的NAME,取出改字段名的值,不存在则创建默认为空 String name = settings.getString(NAME, ""); String password = settings.getString(PASSWORD, ""); //取出保存的PASSWORD,同上 field_name.setText(name);//将取出来的用户名赋予field_name filed_pass.setText(password);//将取出来的密码赋予filed_pass setTitle(name+password);//将NAME和PASSWORD显示在标题栏 } @Override protected void onStop() {// TODO Auto-generated method stubsuper.onStop();//打开SETTING_INFOS.XML//0表示打开模式,有则读,没有则创建 SharedPreferences settings = getSharedPreferences(SETTING_INFOS, 0); //下面一句的语法比较神奇,每次执行都返回一个setting.edit(),commit()表示执行settings.edit() .putString(NAME, field_name.getText().toString()) .putString(PASSWORD, filed_pass.getText().toString()) .commit();//将field_name赋值给NAME字段,将filed_pass赋值给PASSWORD字段 } }//要查看录入的数据,进到DDMS->File Explorer /<package name>/shared_prefs/SETTING_INFOS.XML 难点都在注释里面表面
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