对我希望我的应用做什么的一点描述： 我希望活动中的搜索小部件（不是操作栏），我希望能够搜索我将使用数据库浏览器创建的数据库，我还希望搜索结果显示在同一个活动中（如果是可能的）。
我的数据库将包含3列：项目，类别和说明。 （我还需要一个key_id吗？）。
我一直在使用http://developer.android.com/guide/topics/search/search-dialog.html作为指导。我一路走到＆＃34;搜索您的数据＆＃34;部分，我不知道如何进行。我已经尝试使用谷歌搜索如何做到这一点，我能够偶然发现http://www.reigndesign.com/blog/using-your-own-sqlite-database-in-android-applications/向我展示了如何在Android应用程序中访问数据库。我还查看过＆＃34; Searchable词典＆＃34;在android链接中引用的示例。
这是我第一次做这么大的事情，所以我慢慢开始感到不知所措。我在网上找到的很多教程都展示了如何在应用程序运行时创建/更新/添加/删除数据库和条目，但如果我使用数据库浏览器，这是必要的吗？很多代码都有简单的东西，如声明列，但我不确定在我的情况下是否需要这些。如果任何人都可以提供关于合并搜索功能（一个符合我上面的需求）或指向教程的链接的一般概念的概述，那将不胜感激。现在，我有一个搜索活动，一个dbHelper类，我将需要游标，据我所知，一个将显示结果的类？除非我的搜索活动中的内容也不合适。
SEARCH：
公共类搜索扩展了ActionBarActivity {
private TextView mTextView;
private ListView mListView;
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_search, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public void toMainMenu(View view) {
Intent i=new Intent(Search.this,MainMenu.class);
startActivity(i);
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search);
handleIntent(getIntent());
}
@Override
protected void onNewIntent(Intent intent) {
setIntent(intent);
handleIntent(intent);
}
private void handleIntent(Intent intent) {
if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
String query = intent.getStringExtra(SearchManager.QUERY);
doSearchQuery(query);
}
}
public void doSearchQuery(String query){
//DataBaseHelper myDbHelper = new DataBaseHelper();
DataBaseHelper myDbHelper = new DataBaseHelper(this);
try {
myDbHelper.createDataBase();
} catch (IOException ioe) {
throw new Error("Unable to create database");
}
try {
myDbHelper.openDataBase();
}catch(SQLException sqle){
throw sqle;
}
}
}
我不确定在哪里放置createDataBase和openDataBase。它们应该在doSearchQuery之外吗？
dbHELPER：
公共类DataBaseHelper扩展了SQLiteOpenHelper {
//The Android's default system path of your application database.
public static String DB_PATH = "/data/data/com.example.gus.howtorecycle/databases/";
public static String DB_NAME = "RecycleDB.db";
public static int DB_VERSION = 1;
public static String TABLE_NAME = "Recycle_Table";
public static String COL_1 = "Item";
public static String COL_2 = "Category";
public static String COL_3 = "Description";
private SQLiteDatabase myDataBase;
private final Context myContext;
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access to the application assets and resources.
*/
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own database.
* */
public void createDataBase() throws IOException {
boolean dbExist = checkDataBase();
if(dbExist){
//do nothing - database already exist
}else{
//By calling this method and empty database will be created into the default system path
//of your application so we are gonna be able to overwrite that database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each time you open the application.
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
try{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}catch(SQLiteException e){
//database does't exist yet.
}
if(checkDB != null){
checkDB.close();
}
return checkDB != null;
}
/**
* Copies your database from your local assets-folder to the just created empty database in the
* system folder, from where it can be accessed and handled.
* This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if(myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
// Add your public helper methods to access and get content from the database.
// You could return cursors by doing "return myDataBase.query(....)" so it'd be easy
// to you to create adapters for your views.
}
只是尝试总结一下。我有它，所以它收到一个搜索查询，我有一个数据库，我需要的是在Android中创建该数据库，使用光标搜索它（doSearchQuery），然后才能显示结果。
所以，如果我失去了任何人，我的头脑会有点混乱。如果有人需要澄清，我会监控并回答问题！