Android中數據的保存和提取

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; //接收用戶名的組件

private EditText filed_pass; //接收密碼的組件

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentVIEw(R.layout.main);

field_name = (EditText) findVIEwById(R.id.EditText01); //首先獲取用來輸入用戶名的組件

filed_pass = (EditText) findVIEwById(R.id.EditText02); //同時也需要獲取輸入密碼

// Restore preferences

//獲取一個SharedPreferences對象，SETTING_INFOS與SETTING_INFOS.XML文件相對應

//效果相當於讀取SETTING_INFOS.XML文件，如果文件不存在，則進行創建

SharedPreferences settings = getSharedPreferences(SETTING_INFOS, 0);

//取出保存的NAME，取出改字段名的值，不存在則創建默認為空

String name = settings.getString(NAME, "");

String password = settings.getString(PASSWORD, ""); //取出保存的PASSWord，同上

field_name.setText(name); //將取出來的用戶名賦予fIEld_name

filed_pass.setText(passWord); //將取出來的密碼賦予filed_pass

setTitle(name+password);//將NAME和PASSWord顯示在標題欄

}

@Override

protected void onStop()

{

// TODO Auto-generated method stub

super.onStop();

//打開SETTING_INFOS.XML

//0表示打開模式，有則讀，沒有則創建

SharedPreferences settings = getSharedPreferences(SETTING_INFOS, 0);

//下面一句的語法比較神奇，每次執行都返回一個setting.edit(),commit()表示執行

settings.edit()

.putString(NAME, fIEld_name.getText().toString())

.putString(PASSWord, filed_pass.getText().toString())

.commit();//將fIEld_name賦值給NAME字段，將filed_pass賦值給PASSWord字段

}

}

//要查看錄入的數據，進到DDMS->File Explorer //shared_prefs/SETTING_INFOS.XML