1.实现有道词典需要拖拽一个EditText,一个Button,以及一个TextView。其具体代码如下：

activity类的代码：

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2.MainActivity类的代码：

1 package com.example.happydictionary; 2  3 import android.app.Activity; 4 import android.os.Bundle; 5 import android.text.TextUtils; 6 import android.view.Menu; 7 import android.view.View; 8 import android.widget.EditText; 9 import android.widget.TextView;10 11 import com.example.happydictionary.dao.WordDao;12 13 public class MainActivity extends Activity {14     private WordDao wordDao;15     private EditText etWord;16     private TextView tvResult;17 18     @Override19     protected void onCreate(Bundle savedInstanceState) {20         super.onCreate(savedInstanceState);21         setContentView(R.layout.activity_main);22 23         initViews();24     }25 26     private void initViews() {27         etWord = (EditText) findViewById(R.id.etWord);28         tvResult = (TextView) findViewById(R.id.tvSearchResult);29     }30 31     @Override32     public boolean onCreateOptionsMenu(Menu menu) {33         // Inflate the menu; this adds items to the action bar if it is present.34         getMenuInflater().inflate(R.menu.main, menu);35         return true;36     }37 38     public void searchWord(View view) {39         String english = etWord.getText().toString();40         wordDao = new WordDao(this);41         if (TextUtils.isEmpty(english)) {42             tvResult.setText("请输入您想查询的单词");43         } else {44             String chinese = wordDao.getChinese(english);45             tvResult.setText(chinese);46         }47     }48 49 }

 

 

 3.WordDao类的代码：

1 package com.example.happydictionary.dao; 2  3 import android.content.Context; 4 import android.database.Cursor; 5 import android.database.sqlite.SQLiteDatabase; 6  7 import com.example.happydictionary.db.DBHelper; 8  9 public class WordDao {10      private DBHelper dbHelper;11      private SQLiteDatabase sqLiteDatabase;12      public WordDao(Context context){13          dbHelper=new DBHelper(context);14      }15      public String getChinese(String english){16          sqLiteDatabase=dbHelper.openDatabase();17          String sql="select chinese from t_words where english=?";18          Cursor cursor=sqLiteDatabase.rawQuery(sql, new String[]{english});19          String chinese="查无该词";20          if(cursor.moveToFirst()){21              chinese=cursor.getString(cursor.getColumnIndex("chinese"));22          }23          return chinese;24      }25 }

4.DBHelper类的代码：

1 package com.example.happydictionary.db; 2  3 import java.io.File; 4 import java.io.FileNotFoundException; 5 import java.io.FileOutputStream; 6 import java.io.IOException; 7 import java.io.InputStream; 8  9 import com.example.happydictionary.R;10 import com.example.happydictionary.R.raw;11 12 import android.content.Context;13 import android.database.sqlite.SQLiteDatabase;14 import android.os.Environment;15 import android.util.Log;16 17 /**18  * 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19  * 20  * @author cabbage21  */22 public class DBHelper {23     private final int BUFFER_SIZE = 400000;24     public static final String DB_NAME = "idiom.db"; // 保存的数据库文件名25     public static final String PACKAGE_NAME = "com.example.happydictionary";// 应用的包名26     public static final String DB_PATH = "/data"27             + Environment.getDataDirectory().getAbsolutePath() + "/"28             + PACKAGE_NAME + "/databases";29     /*// SDCard 定义数据库的存放路径30     private final String DATABASE_PATH = android.os.Environment31             .getExternalStorageDirectory().getAbsolutePath() + "/dictionary";*/32 33     private Context context;34 35     public DBHelper(Context context) {36         this.context = context;37     }38 39     public SQLiteDatabase openDatabase() {40         try {41             File myDataPath = new File(DB_PATH);42             if (!myDataPath.exists()) {43                 myDataPath.mkdirs();// 如果没有这个目录则创建44             }45             String dbfile = myDataPath + "/" + DB_NAME;46             if (!(new File(dbfile).exists())) {
   // 判断数据库文件是否存在，若不存在则执行导入，否则直接打开数据库47                 InputStream is = context.getResources().openRawResource(48                         R.raw.dictionary); // 欲导入的数据库49                 FileOutputStream fos = new FileOutputStream(dbfile);50                 byte[] buffer = new byte[BUFFER_SIZE];51                 int count = 0;52                 while ((count = is.read(buffer)) > 0) {53                     fos.write(buffer, 0, count);54                 }55                 fos.close();56                 is.close();57             }58             SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(dbfile,59                     null);60             return db;61         } catch (FileNotFoundException e) {62             Log.e("Database", "File not found");63             e.printStackTrace();64         } catch (IOException e) {65             Log.e("Database", "IO exception");66             e.printStackTrace();67         }68         return null;69     }70 }

5.Word类的代码：

1 package com.example.happydictionary.entity; 2  3 public class Word { 4     private String english; 5     private String chinese; 6  7     public String getEnglish() { 8         return english; 9     }10 11     public void setEnglish(String english) {12         this.english = english;13     }14 15     public String getChinese() {16         return chinese;17     }18 19     public void setChinese(String chinese) {20         this.chinese = chinese;21     }22 23 }

6.DBHelperTest类的代码：

 

1 package com.example.happydictionary.test; 2  3 import com.example.happydictionary.db.DBHelper; 4  5 import android.test.AndroidTestCase; 6  7 public class DBHelperTest extends AndroidTestCase { 8      public void testCreateDB(){ 9          DBHelper dbHelper=new DBHelper(getContext());10          dbHelper.openDatabase();11      }12 }