英语词典小程序

内容简介：

英语词典小程序,是通过打开数据库来查询单词,通过openDatabase()方法来实现,另外也可以使用openDatabase()方法来实现实现从res\raw目录复制数据库文件到/sdcard/dictionary目录中,复制数据实际上先读取，再写入数据的过程。把数据库复制到手机内存中，更方便数据的读取。

效果图：

 





代码：

MainActivity.java

package com.example.happydictionary;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import com.example.happydictionary.adapter.DictionaryAdapter;
import com.example.happydictionary.db.DBHelper;
import android.app.Activity;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.AutoCompleteTextView;
import android.widget.Button;
import android.widget.CursorAdapter;
import android.widget.TextView;

public class MainActivity extends Activity implements OnClickListener,
TextWatcher {
private DBHelper dbHelper; // 用户输入文本框
private AutoCompleteTextView word; // 定义数据库的名字
private SQLiteDatabase database;
private Button searchWord; // 搜索按钮
private TextView showResult; // 用户显示查询结果

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

dbHelper = new DBHelper(getBaseContext());// 打开数据库
database = dbHelper.openDatabase();

init();

searchWord.setOnClickListener(this); // 绑定监听器
word.addTextChangedListener(this); // 绑定文字改变监听器

}

public void init() {
searchWord = (Button) findViewById(R.id.btnSearch);
word = (AutoCompleteTextView) findViewById(R.id.etWord);
showResult = (TextView) findViewById(R.id.tvSearchResult);

}

public void afterTextChanged(Editable s) {
Cursor cursor = database.rawQuery(
"select english as _id from t_words where english like ?",
new String[] { s.toString() + "%" });

// 新建新的Adapter
DictionaryAdapter dictionaryAdapter = new DictionaryAdapter(this,cursor, true);

// 绑定适配器
word.setAdapter(dictionaryAdapter);

}

public void beforeTextChanged(CharSequence s, int start, int count,
int after) {

}

public void onTextChanged(CharSequence s, int start, int before, int count) {

}

public void onClick(View view) {
// 查询指定的单词
String sql = "select chinese from t_words where english=?";

Cursor cursor = database.rawQuery(sql, new String[] { word.getText()
.toString() });

String result = "查无该词"; // 如果查找单词，显示其中文的意思

if (cursor.getCount() > 0) {

cursor.moveToFirst(); // 须使用moveToFirst方法将记录指针移动到第1条记录的位置
result = cursor.getString(cursor.getColumnIndex("chinese"))
.replace("&", "&");
}

showResult.setText(word.getText() + "\n" + result.toString());// 将结果显示到TextView中
}

}

DictionaryAdapter.java

 

 

package com.example.happydictionary.adapter;

import com.example.happydictionary.R;

import android.content.Context;
import android.database.Cursor;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CursorAdapter;
import android.widget.TextView;

//自定义Adapter类
public class DictionaryAdapter extends CursorAdapter {
private LayoutInflater layoutInflater;

@Override
public CharSequence convertToString(Cursor cursor) {
return cursor == null ? "" : cursor.getString(cursor
.getColumnIndex("_id"));
}

// 将单词信息显示到列表中
private void setView(View view, Cursor cursor) {
TextView tvWordItem = (TextView) view;
tvWordItem.setText(cursor.getString(cursor.getColumnIndex("_id")));
}

// 绑定选项到列表中
@Override
public void bindView(View view, Context context, Cursor cursor) {
setView(view, cursor);
}

// 生成新的选项
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
View view = layoutInflater.inflate(R.layout.word_list_item, null);
setView(view, cursor);
return view;
}

public DictionaryAdapter(Context context, Cursor c, boolean autoRequery) {
super(context, c, autoRequery);
layoutInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
}

WordDao.java

package com.example.happydictionary.dao;

import android.content.Context;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

import com.example.happydictionary.db.DBHelper;

public class WordDao {

private DBHelper dbHelper;

private SQLiteDatabase sqLiteDatabase;

public WordDao(Context context){

dbHelper=new DBHelper(context);

}

     public String getChinese(String english){

    sqLiteDatabase=dbHelper.openDatabase();

    String sql="select chinese from t_words where english=?";

    Cursor cursor=sqLiteDatabase.rawQuery(sql, new String[]{english});

    String chinese="查无该词";

    if(cursor.moveToFirst()){

    chinese=cursor.getString(cursor.getColumnIndex("chinese"));

    }

    return chinese;

     }

    

}

DBHelper.java

package com.example.happydictionary.db;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import com.example.happydictionary.R;
import com.example.happydictionary.R.raw;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Environment;
import android.util.Log;

/**
* 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
*
* @author jiajilei
*/
public class DBHelper {
private final int BUFFER_SIZE = 400000;
public static final String NAME = "name";
public static final String DB_NAME = "idiom.db"; // 保存的数据库文件名
public static final String PACKAGE_NAME = "com.example.happydictionary";// 应用的包名
public static final String DB_PATH = "/data"
+ Environment.getDataDirectory().getAbsolutePath() + "/"
+ PACKAGE_NAME + "/databases";
/*// SDCard 定义数据库的存放路径
private final String DATABASE_PATH = android.os.Environment
.getExternalStorageDirectory().getAbsolutePath() + "/dictionary";*/

private Context context;

public DBHelper(Context context) {
this.context = context;
}

public SQLiteDatabase openDatabase() {
try {
File myDataPath = new File(DB_PATH);
if (!myDataPath.exists()) {
myDataPath.mkdirs();// 如果没有这个目录则创建
}
String dbfile = myDataPath + "/" + DB_NAME;
if (!(new File(dbfile).exists())) {// 判断数据库文件是否存在，若不存在则执行导入，否则直接打开数据库
InputStream is = context.getResources().openRawResource(
R.raw.dictionary); // 欲导入的数据库
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;
}

public Cursor query(String name) {
SQLiteDatabase db = this.getReadableDatabase();
return db.rawQuery("select * from t_words where english like '%" + name + "%' limit 10", null);
}

private SQLiteDatabase getReadableDatabase() {
// TODO Auto-generated method stub
return null;
}

}

Word.java

package com.example.happydictionary.entity;

public class Word {
private String english;
private String chinese;

public String getEnglish() {
return english;
}

public void setEnglish(String english) {
this.english = english;
}

public String getChinese() {
return chinese;
}

public void setChinese(String chinese) {
this.chinese = chinese;
}

}

DBHelperTest.java

package com.example.happydictionary.test;

import com.example.happydictionary.db.DBHelper;

import android.test.AndroidTestCase;

public class DBHelperTest extends AndroidTestCase {
public void testCreateDB(){
DBHelper dbHelper=new DBHelper(getContext());
dbHelper.openDatabase();
}
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.happydictionary"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.happydictionary.MainActivity"
android:label="@string/app_name"
android:theme="@android:style/Theme.Black.NoTitleBar" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

<uses-library android:name="android.test.runner" />
</application>

<instrumentation
android:name="android.test.InstrumentationTestRunner"
android:targetPackage="com.example.happydictionary" >
</instrumentation>

</manifest>