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下面是我的代码我按照这个链接如何将值与数据库值进行比较并自定义我的代码我只想在数据库中显示用户在数据库中插入的那个名称但是在getAllApps方法的帮助器类中显示我的错误方法getString（int ) 类型的游标不适用于参数 (String)

  import android.database.sqlite.SQLiteOpenHelper;


  public class DatabaseHandler extends SQLiteOpenHelper {

// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;

// Database Name
private static final String DATABASE_NAME = "contactsManager";

// Contacts table name
private static final String TABLE_CONTACTS = "contacts";

// Contacts Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
//private static final String KEY_PH_NO = "phone_number";

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";
     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( KEY_NAME));
        } while (cursor.moveToNext());
    }

    // return list
    return apps;
}







  }

还有我的活动课

public class PlayStoreApps extends Activity implements 
        OnItemClickListener {
/* whether or not to include system apps */
private static final boolean INCLUDE_SYSTEM_APPS = false;
DatabaseHandler db;
private ListView mAppsList;
private AppListAdapter mAdapter;
private List<App> mApps;
String APKFilePath = "mnt/sdcard/foldername/";

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.games);
    db = new DatabaseHandler(this);
    Button AddMore = (Button) findViewById(R.id.AddMore);
    AddMore.setOnClickListener(new OnClickListener() {
        public void onClick(View view) {

            // Intent intent = new Intent(FunActivity.this,
            // SdcardAPkMgr.class);
            // startActivity(intent);
        }
    });

    mAppsList = (ListView) findViewById(R.id.appslist);
    mAppsList.setOnItemClickListener(this);

    mApps = loadInstalledApps(INCLUDE_SYSTEM_APPS);

    mAdapter = new AppListAdapter(getApplicationContext());
    mAdapter.setListItems(mApps);
    mAppsList.setAdapter(mAdapter);

    new LoadIconsTask().execute(mApps.toArray(new App[] {}));
}

public void onItemClick(AdapterView<?> parent, View view, int position,
        long id) {

    final App app = (App) parent.getItemAtPosition(position);

    AlertDialog.Builder builder = new AlertDialog.Builder(this);

    String msg = app.getTitle()
            + "\n\n"
            + "Version "
            + app.getVersionName()
            + " ("
            + app.getVersionCode()
            + ")"
            + (app.getDescription() != null ? ("\n\n" + app
                    .getDescription()) : "");

    builder.setMessage(msg)
            .setCancelable(true)
            .setTitle(app.getTitle())
            .setIcon(mAdapter.getIcons().get(app.getPackageName()))
            .setPositiveButton("Launch",
                    new DialogInterface.OnClickListener() {
                        public void 
      onClick(DialogInterface dialog, int id) {
                            // start the app by 

    invoking its launch intent
                            Intent i = 
      getPackageManager()

        .getLaunchIntentForPackage(
                                            app.getPackageName());
                            try {
                                if (i != null) {

     startActivity(i);
                                } else {
                                    i = new 
    Intent(app.getPackageName());

     startActivity(i);
                                }
                            } catch 
       (ActivityNotFoundException err) {

  Toast.makeText(PlayStoreApps.this,

     "Error launching app",

         Toast.LENGTH_SHORT).show();
                            }
                        }
                    })
            .setNegativeButton("Cancel",
                    new DialogInterface.OnClickListener() {
                        public void 
         onClick(DialogInterface dialog, int id) {
                            dialog.cancel();
                        }
                    });
    AlertDialog dialog = builder.create();
    dialog.show();
}

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); // 
           PackageManager.GET_META_DATA

    for (int i = 0; i < packs.size(); i++) {
        PackageInfo p = packs.get(i);
        ApplicationInfo applicationInfo = p.applicationInfo;
        String name = packageManager.getApplicationLabel(applicationInfo)
                .toString();

        List arraylist = db.getAllApps();

        if (arraylist.contains(p.packageName))

        {
            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;
}

/**
 * An asynchronous task to load the icons of the installed applications.
 */
private class LoadIconsTask extends AsyncTask<App, Void, Void> {
    @Override
    protected Void doInBackground(App... apps) {

        Map<String, Drawable> icons = new HashMap<String, Drawable>();
        PackageManager manager = getApplicationContext()
                .getPackageManager();

        for (App app : apps) {
            String pkgName = app.getPackageName();
            Drawable ico = null;
            try {
                Intent i = 
       manager.getLaunchIntentForPackage(pkgName);
                if (i != null) {
                    ico = manager.getActivityIcon(i);
                }
            } catch (NameNotFoundException e) {
                Log.e("ERROR", "Unable to find icon for package '"
                        + pkgName + "': " + 
         e.getMessage());
            }
            icons.put(app.getPackageName(), ico);
        }
        mAdapter.setIcons(icons);

        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        mAdapter.notifyDataSetChanged();
    }
}


         }
4

2 回答 2

0

将方法 getAllApps() 更改为

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;
}

并将你
List arraylist = db.getAllApps();
的放在 for 循环之前

于 2013-06-24T08:27:27.907 回答
0 
The method getString(int) in the type Cursor is not applicable for the arguments (String)

那句话说明了一切......你必须将整数参数传递给cursor.getString方法......

假设您要检索第一列数据然后传递 cursor.getString(1).. 等等..

在您的情况下，检查 KEY_NAME .. 的列位置和传递整数列位置....

此外，您有声明String selectQuery = "SELECT * FROM table";..您是否创建了名称为table..的表，如果没有，它将抛出异常，因为表不存在...

你应该试试String selectQuery = "SELECT * FROM "+table_name;

希望这可以帮助...

于 2013-06-24T08:18:44.133 回答