java - 从 SQLite DB 填充的列表项的顺序不正确

Question

我有一个 SQLLite 数据库，用于存储 ftp 站点的登录信息( name 、 address 、 username 、 password 、 port 、 passive )。当单击列表中的某个项目(站点)时，应该将名称、地址、用户名、密码等加载到相应的 EditTexts 中。 。发生的情况是密码值被加载到地址 EditText 中。并且地址没有被加载到任何地方。

我的 Activity addRecord函数如下所示:

public void addRecord() {
    long newId = myDb.insertRow(_name, _address, _username, _password,
            _port, _passive);
    Cursor cursor = myDb.getRow(newId);
    displayRecordSet(cursor);
}

insertRow()中参数的顺序对应我的DBAdapter中的顺序，但是当我更改参数的顺序时，我可以获得正确的地址和密码值 EditTexts ，只是从来没有同时全部。我做错了什么？

    public class DBAdapter {

        // ///////////////////////////////////////////////////////////////////
        // Constants & Data
        // ///////////////////////////////////////////////////////////////////
        // For logging:
        private static final String TAG = "DBAdapter";

        // DB Fields
        public static final String KEY_ROWID = "_id";
        public static final int COL_ROWID = 0;
        /*
         * CHANGE 1:
         */
        // TODO: Setup your fields here:
        public static final String KEY_NAME = "name";
        public static final String KEY_ADDRESS = "address";
        public static final String KEY_USERNAME = "username";
        public static final String KEY_PASSWORD = "password";
        public static final String KEY_PORT = "port";
        public static final String KEY_PASSIVE = "passive";

        // TODO: Setup your field numbers here (0 = KEY_ROWID, 1=...)
        public static final int COL_NAME = 1;
        public static final int COL_ADDRESS = 2;
        public static final int COL_USERNAME = 3;
        public static final int COL_PASSWORD = 4;
        public static final int COL_PORT = 5;
        public static final int COL_PASSIVE = 6;
        public static final String[] ALL_KEYS = new String[] { KEY_ROWID, KEY_NAME,
                KEY_ADDRESS, KEY_USERNAME, KEY_PASSWORD, KEY_PORT, KEY_PASSIVE };

        // DB info: it's name, and the table we are using (just one).
        public static final String DATABASE_NAME = "Sites";
        public static final String DATABASE_TABLE = "SiteTable";
        // Track DB version if a new version of your app changes the format.
        public static final int DATABASE_VERSION = 2;

        private static final String DATABASE_CREATE_SQL = "create table "
                + DATABASE_TABLE
                + " ("
                + KEY_ROWID
                + " integer primary key autoincrement, "

                /*
                 * CHANGE 2:
                 */
                // TODO: Place your fields here!
                // + KEY_{...} + " {type} not null"
                // - Key is the column name you created above.
                // - {type} is one of: text, integer, real, blob
                // (http://www.sqlite.org/datatype3.html)
                // - "not null" means it is a required field (must be given a
                // value).
                // NOTE: All must be comma separated (end of line!) Last one must
                // have NO comma!!
                + KEY_NAME + " string not null, " + KEY_ADDRESS
                + " string not null, " + KEY_USERNAME + " string not null, "
                + KEY_PASSWORD + " string not null, " + KEY_PORT
                + " integer not null," + KEY_PASSIVE + " integer not null"

                // Rest of creation:
                + ");";

        // Context of application who uses us.
        private final Context context;

        private DatabaseHelper myDBHelper;
        private SQLiteDatabase db;

        // ///////////////////////////////////////////////////////////////////
        // Public methods:
        // ///////////////////////////////////////////////////////////////////

        public DBAdapter(Context ctx) {
            this.context = ctx;
            myDBHelper = new DatabaseHelper(context);
        }

        // Open the database connection.
        public DBAdapter open() {
            db = myDBHelper.getWritableDatabase();
            return this;
        }

        // Close the database connection.
        public void close() {
            myDBHelper.close();
        }

        // Add a new set of values to the database.
        public long insertRow(String name, String address, String user,
                String pass, int port, int passive) {
            /*
             * CHANGE 3:
             */
            // TODO: Update data in the row with new fields.
            // TODO: Also change the function's arguments to be what you need!
            // Create row's data:
            ContentValues initialValues = new ContentValues();
            initialValues.put(KEY_NAME, name);
            initialValues.put(KEY_ADDRESS, address);
            initialValues.put(KEY_USERNAME, user);
            initialValues.put(KEY_PASSWORD, pass);
            initialValues.put(KEY_PORT, port);
            initialValues.put(KEY_PASSIVE, passive);
            // Insert it into the database.
            return db.insert(DATABASE_TABLE, null, initialValues);
        }

        // Delete a row from the database, by rowId (primary key)
        public boolean deleteRow(long rowId) {
            String where = KEY_ROWID + "=" + rowId;
            return db.delete(DATABASE_TABLE, where, null) != 0;
        }

        public void deleteAll() {
            Cursor c = getAllRows();
            long rowId = c.getColumnIndexOrThrow(KEY_ROWID);
            if (c.moveToFirst()) {
                do {
                    deleteRow(c.getLong((int) rowId));
                } while (c.moveToNext());
            }
            c.close();
        }

        // Return all data in the database.
        public Cursor getAllRows() {
            String where = null;
            Cursor c = db.query(true, DATABASE_TABLE, ALL_KEYS, where, null, null,
                    null, null, null);
            if (c != null) {
                c.moveToFirst();
            }
            return c;
        }

        // Get a specific row (by rowId)
        public Cursor getRow(long rowId) {
            String where = KEY_ROWID + "=" + rowId;
            Cursor c = db.query(true, DATABASE_TABLE, ALL_KEYS, where, null, null,
                    null, null, null);
            if (c != null) {
                c.moveToFirst();
            }
            return c;
        }

        // Change an existing row to be equal to new data.
        public boolean updateRow(long rowId, String name, String address,
                String username, String password, int port, int passive) {
            String where = KEY_ROWID + "=" + rowId;

            /*
             * CHANGE 4:
             */
            // TODO: Update data in the row with new fields.
            // TODO: Also change the function's arguments to be what you need!
            // Create row's data:
            ContentValues newValues = new ContentValues();
            newValues.put(KEY_NAME, name);
            newValues.put(KEY_ADDRESS, address);
            newValues.put(KEY_USERNAME, username);
            newValues.put(KEY_PASSWORD, password);
            newValues.put(KEY_PORT, port);
            newValues.put(KEY_PASSIVE, passive);
            // Insert it into the database.
            return db.update(DATABASE_TABLE, newValues, where, null) != 0;
        }

        // ///////////////////////////////////////////////////////////////////
        // Private Helper Classes:
        // ///////////////////////////////////////////////////////////////////

        /**
         * Private class which handles database creation and upgrading. Used to
         * handle low-level database access.
         */
        private static class DatabaseHelper extends SQLiteOpenHelper {
            DatabaseHelper(Context context) {
                super(context, DATABASE_NAME, null, DATABASE_VERSION);
            }

            @Override
            public void onCreate(SQLiteDatabase _db) {
                _db.execSQL(DATABASE_CREATE_SQL);
            }

            @Override
            public void onUpgrade(SQLiteDatabase _db, int oldVersion, int newVersion) {
                Log.w(TAG, "Upgrading application's database from version "
                        + oldVersion + " to " + newVersion
                        + ", which will destroy all old data!");

                // Destroy old database:
                _db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);

                // Recreate new database:
                onCreate(_db);
            }
        }
    }

 public class SiteManager extends Activity {
    DBAdapter myDb;
    public FTPClient mFTPClient = null;

    public EditText etSitename;
    public EditText etAddress;
    public EditText etUsername;
    public EditText etPassword;
    public EditText etPort;
    public CheckBox cbPassive;
    public ListView site_list;

    public Button clr;
    public Button test;
    public Button savesite;
    public Button close;
    public Button connect;

    String _name;
    String _address;
    String _username;
    String _password;
    int _port;
    int _passive = 0;

    List<FTPSite> model = new ArrayList<FTPSite>();
    ArrayAdapter<FTPSite> adapter;

    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.site_manager);

        site_list = (ListView) findViewById(R.id.siteList);

        adapter = new SiteAdapter(this, R.id.ftpsitename, R.layout.siterow,
                model);
        site_list.setAdapter(adapter);
        etSitename = (EditText) findViewById(R.id.dialogsitename);
        etAddress = (EditText) findViewById(R.id.dialogaddress);
        etUsername = (EditText) findViewById(R.id.dialogusername);
        etPassword = (EditText) findViewById(R.id.dialogpassword);
        etPort = (EditText) findViewById(R.id.dialogport);
        cbPassive = (CheckBox) findViewById(R.id.dialogpassive);
        close = (Button) findViewById(R.id.closeBtn);

        connect = (Button) findViewById(R.id.connectBtn);
        clr = (Button) findViewById(R.id.clrBtn);
        test = (Button) findViewById(R.id.testBtn);

        savesite = (Button) findViewById(R.id.saveSite);
        addListeners();
        openDb();
        displayRecords();
    }

    public void addListeners() {

        connect.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent returnResult = new Intent();
                returnResult.putExtra("ftpname", _name);
                returnResult.putExtra("ftpaddress", _address);
                returnResult.putExtra("ftpusername", _username);
                returnResult.putExtra("ftppassword", _password);
                returnResult.putExtra("ftpport", _port);
                setResult(RESULT_OK, returnResult);
                finish();

            }
        });

        test.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                _name = etSitename.getText().toString();
                _address = etAddress.getText().toString();
                _username = etUsername.getText().toString();
                _password = etPassword.getText().toString();
                _port = Integer.parseInt(etPort.getText().toString());

                if (cbPassive.isChecked()) {
                    _passive = 1;
                } else {
                    _passive = 0;
                }

                boolean status = ftpConnect(_address, _username, _password,
                        _port);
                ftpDisconnect();

                if (status == true) {
                    Toast.makeText(SiteManager.this, "Connection Succesful",
                            Toast.LENGTH_LONG).show();
                    savesite.setVisibility(0);
                } else {
                    Toast.makeText(SiteManager.this,
                            "Connection Failed:" + status, Toast.LENGTH_LONG)
                            .show();

                }
            }
        });

        savesite.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                _name = etSitename.getText().toString();
                _address = etAddress.getText().toString();
                _username = etUsername.getText().toString();
                _password = etPassword.getText().toString();
                _port = Integer.parseInt(etPort.getText().toString());
                if (cbPassive.isChecked()) {
                    _passive = 1;
                } else {
                    _passive = 0;
                }
                addRecord();
                adapter.notifyDataSetChanged();
            }
        });

        close.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                finish();
            }
        });

        clr.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                clearAll();
            }
        });

        site_list.setOnItemClickListener(new AdapterView.OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, final View view,
                    int position, long id) {
                final FTPSite item = (FTPSite) parent
                        .getItemAtPosition(position);
                String tmpname = item.getName();
                String tmpaddress = item.getAddress();
                String tmpuser = item.getUsername();
                String tmppass = item.getPassword();
                int tmpport = item.getPort();
                String tmp_port = Integer.toString(tmpport);
                int tmppassive = item.isPassive();

                etSitename.setText(tmpname);
                etAddress.setText(tmpaddress);
                etUsername.setText(tmpuser);
                etPassword.setText(tmppass);
                etPort.setText(tmp_port);
                if (tmppassive == 1) {
                    cbPassive.setChecked(true);
                } else {
                    cbPassive.setChecked(false);
                }
            }

        });

    }

    public void addRecord() {
        long newId = myDb.insertRow(_name, _username, _address,_password, 
                _port, _passive);
        Cursor cursor = myDb.getRow(newId);
        displayRecordSet(cursor);
    }

    private void openDb() {
        myDb = new DBAdapter(this);
        myDb.open();
    }

    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        closeDb();
    }

    private void closeDb() {
        myDb.close();
    }

    public void displayRecords() {

        Cursor cursor = myDb.getAllRows();
        displayRecordSet(cursor);
    }

    protected void displayRecordSet(Cursor c) {
        // String msg = "";

        if (c.moveToFirst()) {
            do {
                // int id = c.getInt(0);
                _name = c.getString(1);
                _address = c.getString(2);
                _username = c.getString(3);
                _password = c.getString(4);
                _port = c.getInt(5);

                FTPSite sitesFromDB = new FTPSite();
                sitesFromDB.setName(_name);
                sitesFromDB.setAddress(_address);
                sitesFromDB.setUsername(_username);
                sitesFromDB.setAddress(_password);
                sitesFromDB.setPort(_port);
                sitesFromDB.setPassive(_passive);
                model.add(sitesFromDB);
                adapter.notifyDataSetChanged();
            } while (c.moveToNext());
        }
        c.close();
    }

    public void clearAll() {
        myDb.deleteAll();
        adapter.notifyDataSetChanged();
    }

    public boolean ftpConnect(String host, String username, String password,
            int port) {
        try {
            mFTPClient = new FTPClient();
            // connecting to the host
            mFTPClient.connect(host, port);

            // now check the reply code, if positive mean connection success
            if (FTPReply.isPositiveCompletion(mFTPClient.getReplyCode())) {
                // login using username & password
                boolean status = mFTPClient.login(username, password);

                mFTPClient.enterLocalPassiveMode();
                return status;
            }
        } catch (Exception e) {
            // Log.d(TAG, "Error: could not connect to host " + host );
        }

        return false;
    }

    public boolean ftpDisconnect() {
        try {
            mFTPClient.logout();
            mFTPClient.disconnect();
            return true;
        } catch (Exception e) {
            // Log.d(TAG,
            // "Error occurred while disconnecting from ftp server.");
        }

        return false;
    }

    class SiteAdapter extends ArrayAdapter<FTPSite> {
        private final List<FTPSite> objects;
        private final Context context;

        public SiteAdapter(Context context, int resource,
                int textViewResourceId, List<FTPSite> objects) {
            super(context, R.id.ftpsitename, R.layout.siterow, objects);
            this.context = context;
            this.objects = objects;
        }

        /** @return The number of items in the */
        public int getCount() {
            return objects.size();
        }

        public boolean areAllItemsSelectable() {
            return false;
        }

        /** Use the array index as a unique id. */
        public long getItemId(int position) {
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            LayoutInflater inflater = (LayoutInflater) context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

            View rowView = inflater.inflate(R.layout.siterow, parent, false);
            TextView textView = (TextView) rowView
                    .findViewById(R.id.ftpsitename);

            textView.setText(objects.get(position).getName());

            return (rowView);
        }
    }

Answer 1

我认为你应该尝试使用:

     int keyNameIndex = c.getColumnIndex(DBAdapter.KEY_NAME);
      _name = c.getString(keyNameIndex);

而不是使用直接数字。我不确定它会导致错误，但它会是更好的练习。希望对您有所帮助。