乐学成语

一、功能需求：

      1.成语分类学习：用户可以根据自己喜欢的分类来进行选择学习，其中包括（动物类、人物类、季节类、自然类、数字类、寓言类、其他类）7个类。

      2.乐猜成语：学习之余玩玩猜成语游戏，寓教于乐。

      3.成语收藏：当用户遇到自己想要保存的成语，点击保存按钮，即可以保存到收藏页面以方便用户再次查看，对已经掌握的成语，用户可以从收藏夹中删除。

      4.成语查询：输入成语的首字母即可查询该成语。

二、创建包和数据库：

      1.在com.edu.happyidiom下创建几个新包：

     

       其中adapter包用于存放所有活动相关的代码，db包用于存放所有数据库相关的代码，entity包用于存放所有实体相关的代码，dao包用于存放所有与数据操作相关的代码。ADT自动生成的MainActivity个activity_main.xml就不需要了，这里直接将它们删掉。

      2.创建数据库和表：

     

     

    

三、在各个包中新建与所实现功能对应的类，并编写代码：

      1.DBOpenHelper类，实现将数据库文件从raw目录拷贝到手机里存放数据库的位置：  

public class DBOpenHelper {private final int BUFFER_SIZE=400000;//缓冲区大小public static final String DB_NAME="idioms.db"; //保存的数据库文件名public static final String PACKAGE_NAME="com.example.happyidiom";//应用的包名public static final String DB_PATH="/data"+Environment.getDataDirectory().getAbsolutePath()+"/"+PACKAGE_NAME+"/databases";//在手机里存放数据库的位置private Context context;public DBOpenHelper(Context context){this.context=context;}public SQLiteDatabase openDatabase(){try{File myDataPath=new File(DB_PATH);if(!myDataPath.exists()){myDataPath.mkdirs();//如果没有这个数据库则创建}String dbfile=myDataPath+"/"+DB_NAME;if(!(new File(dbfile).exists())){//判断数据库文件是否存在，若不存在直接导入，//否则直接打开数据库InputStream is=context.getResources().openRawResource(R.raw.idioms);FileOutputStream fos=new FileOutputStream(dbfile);byte[] buffer=new byte[BUFFER_SIZE];int count=0;while((count=is.read(buffer))>0){fos.write(buffer, 0,count);}fos.close();is.close();}SQLiteDatabase db=SQLiteDatabase.openOrCreateDatabase(dbfile, null);return db;}catch(FileNotFoundException e){Log.e("Database","File not found");e.printStackTrace();}catch(IOException e){Log.e("Database","IO exception");e.printStackTrace();}return null;}}

      2.为了检验idioms.db中数据有没有复制成功，需要修改AndroidManifest.xml搭建单元测试环境：

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.happyidiom"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="15"        android:targetSdkVersion="17" />    <application        android:allowBackup="true"        android:icon="@drawable/logo"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <uses-library android:name="android.test.runner" />        <activity            android:name="com.example.happyidiom.MainActivity"            android:label="@string/title_activity_main"            android:theme="@android:style/Theme.NoTitleBar" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <activity            android:name="com.example.happyidiom.StudyActivity"            android:label="@string/title_activity_study" >        </activity>        <activity            android:name="com.example.happyidiom.StudyAnimalActivity"            android:label="@string/title_activity_study_animal" >        </activity>              <activity            android:name="com.example.happyidiom.StudyOtherActivity"            android:label="@string/title_activity_study_other" >        </activity>    </application>    <instrumentation        android:name="android.test.InstrumentationTestRunner"        android:targetPackage="com.example.happyidiom" >    </instrumentation></manifest>

      3.检验数据库有没有复制成功：
      

      4.新建Animal实体类：

public class Animal {private int id;private String name;private String pronounce;private String explain;private String autonym;private String homoionym;private String derivation;private String examples;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getPronounce() {return pronounce;}public void setPronounce(String pronounce) {this.pronounce = pronounce;}public String getExplain() {return explain;}public void setExplain(String explain) {this.explain = explain;}public String getAutonym() {return autonym;}public void setAutonym(String autonym) {this.autonym = autonym;}public String getHomoionym() {return homoionym;}public void setHomoionym(String homoionym) {this.homoionym = homoionym;}public String getDerivation() {return derivation;}public void setDerivation(String derivation) {this.derivation = derivation;}public String getExamples() {return examples;}public void setExamples(String examples) {this.examples = examples;}}

      5.创建AnimalDao类：

public class AnimalDao {private static AnimalDao animalDao;private SQLiteDatabase db;/** * 将构造方法私有化 */private AnimalDao(Context context){DBOpenHelper dbHelper =new DBOpenHelper(context);db=dbHelper.openDatabase();}/** * 获取AnimalDao的实例 */public synchronized static AnimalDao getInstance(Context context){if(animalDao==null){animalDao=new AnimalDao(context);}return animalDao;}/** * 从数据库获取所有的动物类成语 */public List<Animal> getAllAnimals(){List<Animal> list=new ArrayList<Animal>();Cursor cursor =db.query("animal",null, null,null,null,null,null);if(cursor.moveToFirst()){do{Animal animal=new Animal();animal.setId(cursor.getInt(cursor.getColumnIndex("_id")));animal.setName(cursor.getString(cursor.getColumnIndex("name")));animal.setPronounce(cursor.getString(cursor.getColumnIndex("pronounce")));animal.setAutonym(cursor.getString(cursor.getColumnIndex("antonym")));animal.setHomoionym(cursor.getString(cursor.getColumnIndex("homoionym")));animal.setDerivation(cursor.getString(cursor.getColumnIndex("derivation")));animal.setExamples(cursor.getString(cursor.getColumnIndex("explain")));                list.add(animal);}while(cursor.moveToNext());}return list;}}

      6.运行单元测试：

     

四、显示主界面：

      1.在res的drawable-hdpi目录拷入需要的图片素材，在res/layout目录中新建activity_main.xml布局，代码如下：

     

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context=".MainActivity" >    <TabHost         android:id="@android:id/tabhost"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_alignParentLeft="true"        android:layout_alignParentTop="true"        >    <LinearLayout        android:layout_width="match_parent"        android:layout_height="match_parent"        android:orientation="vertical"        >        <FrameLayout        android:id="@android:id/tabcontent"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_weight="1"            >            <LinearLayout                 android:id="@+id/tab1"                 android:orientation="vertical"                 android:layout_width="match_parent"                 android:layout_height="match_parent"                >            </LinearLayout>            <LinearLayout                 android:id="@+id/tab2"                 android:orientation="vertical"                 android:layout_width="match_parent"                 android:layout_height="match_parent"                >            </LinearLayout>            <LinearLayout                 android:id="@+id/tab3"                 android:orientation="vertical"                 android:layout_width="match_parent"                 android:layout_height="match_parent"                >            </LinearLayout>        </FrameLayout>        <TabWidget            android:id="@android:id/tabs"            android:layout_width="match_parent"        android:layout_height="wrap_content">        </TabWidget>    </LinearLayout>            </TabHost>  </RelativeLayout>

      2.修改res/strings.xml文件：

<?xml version="1.0" encoding="utf-8"?><resources>    <string name="app_name">HappyIdiom</string>    <string name="action_settings">Settings</string>    <string name="hello_world">Hello world!</string>    <string name="title_activity_main">MainActivity</string>    <string name="title_search">搜搜</string>    <string name="title_study">学习</string>    <string name="title_game">游戏</string>    <string name="title_save">收藏</string>    <string name="title_help">帮助</string>    <string name="animal">动物类</string>    <string name="number">数字类</string>    <string-array name="category">        <item>动物类</item>        <item>数字类</item>        <item>人物类</item>        <item>季节类</item>        <item>自然类</item>        <item>寓言类</item>        <item>其他类</item>    </string-array>    <string name="title_activity_study">StudyActivity</string>    <string name="title_activity_study_animal">StudyAnimalActivity</string>    <string name="title_activity_study_other">StudyOtherActivity</string></resources>

五、

1.在com.example.happyidiom中创建MainActivity继承Avtivity类：

public class MainActivity extends TabActivity {private TabHost tabHost;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);requestWindowFeature(Window.FEATURE_NO_TITLE);setContentView(R.layout.activity_main);tabHost=getTabHost();addTab("study", R.string.title_study, R.drawable.study,StudyActivity.class);addTab("search", R.string.title_search, R.drawable.search, StudyActivity.class);addTab("game", R.string.title_game, R.drawable.game, StudyActivity.class);addTab("save", R.string.title_save, R.drawable.save, StudyActivity.class);addTab("help", R.string.title_help, R.drawable.help, StudyActivity.class);}private void addTab(String tag,int title_introduction,int title_icon,Class ActivityClass){tabHost.addTab(tabHost.newTabSpec(tag).setIndicator(getString(title_introduction), getResources().getDrawable(title_icon)).setContent(new Intent(this,ActivityClass)));}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}}

     2.定义一个实体类，作为ListView适配器的适配类型。在entity包下创建Category：

public class Category {private String name;private int imageId;public Category(String name, int imageId) {super();this.name = name;this.imageId = imageId;}public String getName() {return name;}public int getImageId() {return imageId;}}

        3.在com.example.happyidiom中创建StudyActivity继承Avtivity类：

public class StudyActivity extends Activity {private List<Category> categoryList;    private String[] category_names;    private int[] category_images;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_study);initCategory();CategoryAdapter adapter=new CategoryAdapter(this, R.layout.category_item, categoryList);ListView listView=(ListView) findViewById(R.id.lvCategories);    listView.setAdapter(adapter);    listView.setOnItemClickListener(new OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> adapterView, View view, int position,long id) {// TODO Auto-generated method stubIntent intent;switch(position){case 0: intent=new Intent(StudyActivity.this,StudyAnimalActivity.class);startActivity(intent);break;case 6: intent=new Intent(StudyActivity.this,StudyOtherActivity.class);startActivity(intent);break;default:break;}}});}private void initCategory() {// TODO Auto-generated method stubcategoryList=new ArrayList<Category>();Resources resources=getResources();category_names=resources.getStringArray(R.array.category);category_images=new int[]{R.drawable.category_animal,R.drawable.category_nature,R.drawable.category_human,R.drawable.category_season,R.drawable.category_number,R.drawable.category_fable,R.drawable.category_other};for(int i=0;i<category_names.length;i++){categoryList.add(new Category(category_names[i], category_images[i]));}}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.study, menu);return true;}}

   
特此声明：其他的几个类与Animal类相似。