2013-06-24 18 views
0

在我的應用程序中,我從Google Play插入用戶訪問應用程序包名稱並將其保存在數據庫中。我只顯示包名稱在數據庫中的安裝應用程序中的那些應用程序。如何比較我的數據庫中的值?

值成功插入到數據庫中,但是當我在PlayStoreApps類在這一行if (arraylist.equals(p.packageName))比較:

public class PlayStoreApps extends Activity implements OnItemClickListener { 

    private static final boolean INCLUDE_SYSTEM_APPS = false; 
    DatabaseHandler db; 
    private ListView mAppsList; 
    private AppListAdapter mAdapter; 
    private List<App> mApps; 

    db = new DatabaseHandler(this); 

    private List<App> loadInstalledApps(boolean includeSysApps) { 
     List<App> apps = new ArrayList<App>(); 

     // the package manager contains the information about all installed apps 
     PackageManager packageManager = getPackageManager(); 

     List<PackageInfo> packs = packageManager.getInstalledPackages(0); 
     List arraylist = db.getAllApps(); 

     for (int i = 0; i < packs.size(); i++) { 
      PackageInfo p = packs.get(i); 
      ApplicationInfo applicationInfo = p.applicationInfo; 

      if (arraylist.equals(p.packageName)) { 
       // if ((p.packageName).equals(arraylist)) 
       App app = new App(); 
       app.setTitle(p.applicationInfo.loadLabel(packageManager).toString()); 
       app.setPackageName(p.packageName); 
       app.setVersionName(p.versionName); 
       app.setVersionCode(p.versionCode); 
       CharSequence description = p.applicationInfo.loadDescription(packageManager); 
       app.setDescription(description != null ? 
       description.toString() : ""); 
       apps.add(app); 
      } 
     } 
     return apps; 
    } 

    public class Search extends Activity { 
     /** Called when the activity is first created. */ 
     DatabaseHandler db; 
     WebView web; 
     @Override 
     public void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.search); 
      db = new DatabaseHandler(this); 

      String id= url.substring(Standard .length(), url.indexOf("&")); 
      db.addContact(new Contact(id)); 

      Log.d("Reading: ", "Reading all contacts.."); 
      List<Contact> contacts = db.getAllContacts();  

      for (Contact cn : contacts) { 
       String log = "Id: "+cn.getID()+" ,Name: " + cn.getName() ; 

       // String log = "Id: "+cn.getID()+" ,Name: " + cn.getName() + " ,Phone: " + cn.getPhoneNumber(); 
       // Writing Contacts to log 
       Log.d("Name: ", log); 
      } 

      view.loadUrl(url); 

      return true; 
     } 

public class DatabaseHandler extends SQLiteOpenHelper { 

    private static final int DATABASE_VERSION = 1; 

    private static final String DATABASE_NAME = "contactsManager"; 

    private static final String TABLE_CONTACTS = "contacts"; 

    private static final String KEY_ID = "id"; 
    private static final String KEY_NAME = "name"; 

    public DatabaseHandler(Context context) { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    } 

    // Creating Tables 
    @Override 
    public void onCreate(SQLiteDatabase db) { 
    // String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"+ KEY_PH_NO + " TEXT" + ")"; 

     String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT" + " UNIQUE " + ")"; 

     db.execSQL(CREATE_CONTACTS_TABLE); 
    } 

    // Upgrading database 
    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     // Drop older table if existed 
     db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS); 

     // Create tables again 
     onCreate(db); 
    } 

    /** 
    * All CRUD(Create, Read, Update, Delete) Operations 
    */ 

    // Adding new contact 
    void addContact(Contact contact) { 
     SQLiteDatabase db = this.getWritableDatabase(); 

     ContentValues values = new ContentValues(); 
     values.put(KEY_NAME, contact.getName()); // Contact Name 
    // values.put(KEY_PH_NO, contact.getPhoneNumber()); // Contact Phone 

     // Inserting Row 
     db.insert(TABLE_CONTACTS, null, values); 
     db.close(); // Closing database connection 
    } 

    // Getting single contact 
    Contact getContact(int id) { 
     SQLiteDatabase db = this.getReadableDatabase(); 

     Cursor cursor = db.query(TABLE_CONTACTS, new String[] { KEY_ID, KEY_NAME }, KEY_ID + "=?", new String[] { String.valueOf(id) }, null, null, null, null); 
     if (cursor != null) 
      cursor.moveToFirst(); 

     Contact contact = new Contact(Integer.parseInt(cursor.getString(0)), cursor.getString(1)); 
     // return contact 
     return contact; 
    } 

    // Getting All Contacts 
    public List<Contact> getAllContacts() { 
     List<Contact> contactList = new ArrayList<Contact>(); 
     // Select All Query 
     String selectQuery = "SELECT * FROM " + TABLE_CONTACTS; 

     SQLiteDatabase db = this.getWritableDatabase(); 
     Cursor cursor = db.rawQuery(selectQuery, null); 

     // looping through all rows and adding to list 
     if (cursor.moveToFirst()) { 
      do { 
       Contact contact = new Contact(); 
       contact.setID(Integer.parseInt(cursor.getString(0))); 
       contact.setName(cursor.getString(1)); 
       //contact.setPhoneNumber(cursor.getString(2)); 
       // Adding contact to list 
       contactList.add(contact); 
      } while (cursor.moveToNext()); 
     } 

     // return contact list 
     return contactList; 
    } 

    // Updating single contact 
    public int updateContact(Contact contact) { 
     SQLiteDatabase db = this.getWritableDatabase(); 

     ContentValues values = new ContentValues(); 
     values.put(KEY_NAME, contact.getName()); 
// values.put(KEY_PH_NO, contact.getPhoneNumber()); 

     // updating row 
     return db.update(TABLE_CONTACTS, values, KEY_ID + " = ?", new String[] { String.valueOf(contact.getID()) }); 
    } 

    // Deleting single contact 
    public void deleteContact(Contact contact) { 
     SQLiteDatabase db = this.getWritableDatabase(); 
     db.delete(TABLE_CONTACTS, KEY_ID + " = ?", new String[] { String.valueOf(contact.getID()) }); 
     db.close(); 
    } 

    public int deleteContact() { 
     try { 
      SQLiteDatabase db = this.getWritableDatabase(); 
      return db.delete(TABLE_CONTACTS, null, null); 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
     return 0; 
    } 

    // Getting contacts Count 
    public int getContactsCount() { 
     String countQuery = "SELECT * FROM " + TABLE_CONTACTS; 
     SQLiteDatabase db = this.getReadableDatabase(); 
     Cursor cursor = db.rawQuery(countQuery, null); 
     cursor.close(); 

     // return count 
     return cursor.getCount(); 
    } 

    public ArrayList<String> getAllApps() { 

     String selectQuery = "SELECT * FROM "+TABLE_CONTACTS; 
     ArrayList<String> apps = new ArrayList<String>(); 
     SQLiteDatabase db = this.getWritableDatabase(); 
     Cursor cursor = db.rawQuery(selectQuery, null); 

     // looping through all rows and adding to list 
     if (cursor.moveToFirst()) { 
      do { 
       apps.add(cursor.getString(cursor.getColumnIndex(KEY_NAME))); 
      } while (cursor.moveToNext()); 
     } 

     // return list 
     return apps; 
    } 
} 
+0

此行if(arraylist.equals(p.packageName))不是過濾值 –

+0

您是否意識到這是完全不可讀的?請分類,刪除空行並刪除不需要的註釋。 –

+0

oki發佈w8 –

回答

0

第一:不使用非通用Lists

在你loadInstalledApps方法,您可以使用這一行:

List arraylist = db.getAllApps(); 

由於getAllApps返回一個ArrayList<String>您的List應該是List<String>類型。

二:你不能在列表中的項目比較像你想做什麼:

if(arraylist.equals(p.packageName) 

你基本上想看看是否ArrayList對象等於String。比較蘋果和橙子也不太好......

第三:比較代碼而不是比較SQL在性能方面真的很慢,應該避免,尤其是在移動操作系統上,因爲這是浪費內存和中央處理器。

如果你真的想在代碼中進行比較,你可以做這樣的:

if(arraylist.contains(p.packageName)) { 
    // Do something 
    App app = new App(); 
    app.setTitle(p.applicationInfo.loadLabel(packageManager).toString()); 
    app.setPackageName(p.packageName); 
    app.setVersionName(p.versionName); 
    app.setVersionCode(p.versionCode); 
    CharSequence description = p.applicationInfo.loadDescription(packageManager); 
    app.setDescription(description != null ? 
    description.toString() : ""); 
    apps.add(app); 
} 

但我不會推薦這條道路。