南郵安卓期末復習2021-1

// 僅粉絲可見~

復習資料：
NIIT教材
閉卷考試，試卷共4頁，題型：
1、單項選擇題（10道，每道2分）；
2、判斷題（10道，每道2分）；
3、簡答題（6道，每道5分）；
4、編程題（4道，7+7+7+9分）
注：題目均為英文，要求回答也使用英文，不會的單詞考試時可以舉手提問；

基礎：

安卓核心組件？安卓的key feature？哪些核心組件沒有 UI 界面？

Activity Service Broadcast Content Provider

Integrated browser
Sqlite
Media support
Wireless services: bluetooth wifi
Dalvik virtual machine(DVM)
Application framework
Rich development environment

Android Architecture分為幾層？每一層都有些什么內容？（尤其是下面2層要清楚）

Applications: this layer correspond to the core applications part of the software stack
Application framework: this layer along with the libraries and android runtime layer corresponds to the middleware part of the software stack
Libraries and android runtime: this layer along with the application framework layer corresponds to the middleware part of the software stack
Libraries:
OpenGL ES
Meida framework
Surface manager
Sqlite
WebKit
libc
android runtime:
core libraries
DVM
Linux kernel: correspond to the operating system part of the android software stack
Display driver
wifi driver
camera driver
power management
flash memory driver
binder driver
keypad driver
audio drivers

安卓用什么資料庫？有什么特點？

Sqlite
Open-src
standard
Light
Single-tier
No server
Loose-type
App-process

安卓應用開發是基于什么語言的？安卓App運行的Java虛擬機簡稱是什么？

Java and C++
DVM(Dalvik virtual machine)

R.java 是什么檔案？干什么用的？

Files saved in res directory will be compiled and given resource ID, which will be saved in R.java file. We can access resources in the res directory by R.java

安卓的UI用戶點擊后，運行哪一個事件處理器？

Interface: View.OnClickListener method: OnClick(view)
side_tip.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
drawerLayout.openDrawer(navigationView);
}
});

Intent 有幾個組件？各是干什么用的？哪些組件是必須存在的，哪些是可選的，在Manifest中 intent filter 是如何宣告的？

Component name: specify a fully qualified class name of the target component
Action: the action that needs to be performed
Data: the data to operate on
Category: the behavior of the target app component
Extras: extra information in the form of key-value pairs that must be delivered to the components that handle the intent
Flags: flags that control various aspects related to activating a new component

In the , is mandatory, and are optional

Activity的生命周期有哪些狀態？狀態轉換時呼叫的方法各是什么？

書上圖片
Running stopped paused

安卓日志類 Log有哪些方法？各用于什么輸出什么資訊？

Log.e(): errors
Log.w(): warnings
Log.i(): info
Log.d(): debug
Log.v(): verbose

是什么？做什么用的？

A label that represents a permission action in AndoridManifest.xml
Declare the permissions required by the android application

核心機制：

什么是SharedPreference，支持存放哪些型別的資料？

Shared preferences are lightweight mechanism used to store key-value pairs of primitive data types
Boolean，Float，Int，Long，String

什么是Content Provider，創建一個Content Provider的大致步驟是什么？里面的聯系人 URI 形式是什么樣的？

Content provider can store and retrieve data making it accessible to all apps

1. Create a custom content provider
2. Specify the URI of a content provider
3. Implement query handling methods
4. Access the data exposed by a content provider
5. Handle requests for the MIME type of data
6. Register a custom content provider

public static final Uri CONTENT_URI = Uri.parse(“content://.provider./

什么是Broadcast Receiver，創建它需要重寫哪些方法？

Broadcast receiver is a component of an app that responds to system-wide broadcast announcements

onReceive()

什么是Intent、Intent Filter，一般用來做什么？

Intent is a message used to activate app components, pass data between app components
Intent filter is used to filter implicit intent, if a match is found in action, data and category, the intent is delivered to the component that owns the filter

什么是Service，Service有哪些狀態？一般用來承擔什么功能？

A service is an app component that doesn`t have UI and can perform long-running operations in the background

Started service: upload file
書上圖片
Bound service: music player
書上圖片

Broadcast有哪幾種？區別？

Normal broadcasts: broadcasts are sent to all interested receivers at the same time and receivers run in an undefined order
Ordered broadcasts: broadcasts are sent to all interested receivers in a proper order. When a receiver receives a broadcast, it can either propagate the broadcast to the next or it can abort the broadcast

LogCat 是做什么用的？

The logcat enables to monitor app`s log output on the simulator. Developer can examine these logs to debug app.

IO：

安卓原生支持幾種IO機制？各自有什么特點？哪些是可以public訪問的？

Sqlite database: 見上
Internal storage: data be stored is small and can be stored in files instead of a database
External storage: it provide a large capacity that allow user to store
Shared preference: it allows to retrieve persistent key-value pairs of primitive data types
Remote location: it can update frequently from the web and send it to the application

Internal storage
Remote location

卸載安卓App，該App在internal storage 里的內容會被自動洗掉嗎？

yes

安卓原生的content provider有哪些？

Browser
Contacts
Call log
Media store
setting

判斷SD卡是否可用，用什么方法？

if ( Environment.MEDIA_MOUNTED.equals(Enviroment.getExternalStorageState()) )

Shared Preferences 是什么？有什么用？

1)Shared preferences are a lightweight mechanism used to store key-value pairs of primitive
data types
2)Shared Preference are an ideal preferences.They are most frequently used to persist data
across user sessions and to share settings between application components

要從遠端URL播放多媒體檔案用什么stream？

http stream

創建一個安卓資料庫都有哪些途徑？

1)Creating a database programmatically
2)Creating a database through shell commands

MediaPlayer 是什么？包含哪些內容？

Mediaplayer is the android multimedia framework. It can fetch, decode, play audio and video stored in local resources, internal URIs, external URLs

UI：

View類 與普通控制元件的 區別是什么？

The view class is the base class for all normal controls

Activity 運行以后，哪個方法 負責 將外觀與Activity 關聯起來？

setContentView(R.layout.activity_main);

安卓內建的theme有哪些？

1)Theme.Black
2)Theme.Light
3)Theme.Translucent
4)Theme.Dialog
5)Theme.Holo

<style> declares a style
It can be reused through inherit other style

Options Menu是什么？Context Menu是什么？兩者區別？Context Menu按下時，事件處理器是什么？

1)Options Menu is the primary collection of menu items for an activity, which appears when the user presses the MENU button on the emulator/device.
2)Context Menu is a floating list of menu items that appears when user touches and holds a view that is registered to provide a context menu.

OnContextItemSelected()

安卓畫圖相關的主要有哪3個類？各自作用？

1)Canvas: A Canvas represents a surface where you can draw shapes and images;
2)Paint:The Paint class in Android provides information about the style and color for drawing symbols,text, and graphics;
3)Bitmap :A bitmap image uses pixels to create graphics.

什么是 compound view？

Compound views refer to combining multiple views into a logical group of items that can be treated as a single view.

其他：

安卓支持哪幾種Location Provider？如何獲得位置提供者，具體方法類有哪些？哪種精確度高？

GPS、Cell tower triangulation 、Public wifi hotspots
Android uses the LocationManager class and the getProvider() method to find the name of all the location providers that are available on the mobile device.

GPS

安卓收到一個短信，會觸發什么樣的broadcast？想要讀取短信，需要申請什么權限（限教材）？SmsManager 是什么？包含哪些內容？

When an SMS is received by an Android system,it triggers a broadcast with action as SMS_RECEIVED,which notifies all the receivers that an SMS has been received.

SmsManger enables you to take advantage of the android message services. Messages are sent in android by using the SmsManager class.

情景編程：（只要求寫出關鍵代碼或者思路、步驟（要點要全，否則扣分）即可）

1、撥號

Intent intent = new Intent(Intent.ACTION_DIAL,Uri.parse(“tel:110”));
startActivity(intent);

2、如何獲取當前地理位置（經緯度）.

a.申請權限
<uses-permission android:name=" android.permission.ACCESS_FINE_LOCATION”/>
b.獲取LocationManger
LocationManger Im= new LocationManager();
c.獲取providers
List providers = lm.getProviders(true);
d.選擇一個provider
e.獲取location
Location location = lm.getCurrentLocation(provider);
f.獲取經緯度
location.getLatitude() location.getLongtitude()

3、如何發起一個有聲音、震動、閃燈的 status bar notification ？

1:獲取NotificationManager實體
String serviceName = Context.NOTIFICATION_SERVICE;
NotificationManager nm = (NotificationManager)getSystemService(serviceName);
2:創建Notification物件:
Notification notification = new Notification(icon, text, System.currentTimeMillis());
3:設定拉出notification window后顯示的內容
setLatestEventInfo(Context con, CharSequence title, CharSequence text, PendingIntent i);
4:設定默認的聲音震動閃燈
notification.defaults |= Notification.DEFAULT_SOUND;
notification.defaults |= Notification.DEFAULT_VIBRATE;
notification.defaults |= Notification.DEFAULT_LIGHTS;

4、如何讀取一個SQLite資料庫中某個表的某一行？

SQLiteDatabase db= new SQLiteOpenHelper(context, databaseName, null, version).getReadableDatabase()
String selectQuery="SELECT "+
        User.KEY_name +
        " FROM " + User.TABLE +
        " WHERE " + User.KEY_email + "=?";
Cursor cursor=db.rawQuery(selectQuery, new String[]{email});
String name = null;
if(cursor.moveToFirst()){
    do{
        name = cursor.getString(cursor.getColumnIndex(User.KEY_name));
    }while(cursor.moveToNext());
}
cursor.close();
db.close();

5、如何播放一個 SD卡 上的 音樂檔案，播放30秒后 暫停?

1:獲取權限
<uses-permission android:name=" android.permission.WRITE_EXTERNAL_STORAGE”>
2:存入檔案

FileInputStream fis = new FileInputStream(Environment.getExternalStorageDirectory()+”//”+music.mp3); 
FileOutputStream fos = new FileOutputStream(“res/raw/xxx.mp3”);               
byte datas[] = new byte[1024*8]; 
int len = 0;//創建長度   
while((len = fis.read(datas))!=-1) 
{
	fos.write(datas,0,len);
} 
fis.close();
fis.close();
MediaPlayer mediaplayer = MediaPlayer.create(context, R.raw.xxx.mp3);
mediaplayer.start();
Thread.sleep(1000*30);
mediaplayer.pause();

6、發送短信

1）獲取SmsManager: SmsManager smsM= SmsManager.getDefault();
2）申請權限:
3）發送: smsM.sendTextMessage(String dstAddr,//對方手機號, “139139139139”
String smsc,// (Short Message Service Center)地址，null取默認
String txt, PendingIntent sent,//發出后廣播的訊息
PendingIntent deliver);//對方收到后廣播的訊息