Question

我想使用SimpleCursorAdaptor显示联系信息，当我从数据库获取信息时它没有显示任何内容。但我已通过cursor.count（）检查存在数据。

这是listactivity

public class Contacts extends ListActivity {

private ArrayList<TempInfo> contactsList = null;
// Attributes

private static String name = "";
private static String phone = "";
private static int rowId = 0;

@SuppressWarnings("unchecked")
@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.contact_list);

    contactsList = new ArrayList<TempInfo>();
    CardsDatabase info = new CardsDatabase(this);
    info.open();

    Cursor c = info.geTContactsData();
    Log.d("cursor length",Integer.toString(c.getCount()));
    c.moveToFirst();
    while (c.isAfterLast() == false) {
        name = c.getString(c.getColumnIndex(CardsDatabase.NAME_R));
        phone = c.getString(c.getColumnIndex(CardsDatabase.PHONE_R));
        rowId = c.getInt(c.getColumnIndex(CardsDatabase.ROW_R));

        TempInfo s = new TempInfo(rowId, name, phone);
        contactsList.add(s);

        c.moveToNext();
    }

    c.close();

    Cursor cursor = info.geTContactsData();
    startManagingCursor(cursor);

    String[] columns = new String[] { CardsDatabase.ROW_R,
            CardsDatabase.NAME_R, CardsDatabase.PHONE_R };

    int[] to = new int[] { R.id.row_id, R.id.contact_name,
            R.id.contact_number };

    SimpleCursorAdapter mAdapter = new SimpleCursorAdapter(Contacts.this,
            R.layout.contact_list_entry, cursor, columns, to);
    this.setListAdapter(mAdapter);
    cursor.close();

}

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {

    super.onListItemClick(l, v, position, id);
    TempInfo tempInfo = contactsList.get(position);

    Intent i = new Intent(Contacts.this, ContactsDetail.class);
    Bundle bundle = new Bundle();
    bundle.putInt("rowid", tempInfo.rowid);
    i.putExtra("personBundle", bundle);
    startActivity(i);

}

}

这是contact_list xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<TextView
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:background="#66000000"
    android:cacheColorHint="#6E000000"
    android:paddingLeft="5dp"
    android:text="   Contacts"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:textColor="#ffffff" />

<ListView
    android:id="@android:id/list"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="2"
    android:cacheColorHint="#00000000" >
</ListView>

这是contact_list_entry xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="?android:attr/listPreferredItemHeight"
android:padding="6dip" >

<TextView
    android:id="@+id/row_id"
    android:layout_width="25dp"
    android:layout_height="fill_parent"
    android:background="#5C5858"
    android:textColor="#ffffff" />

<LinearLayout
    android:layout_width="0dip"
    android:layout_height="fill_parent"
    android:layout_weight="1"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/contact_name"
        android:layout_width="fill_parent"
        android:layout_height="0dip"
        android:layout_weight="1"
        android:ellipsize="marquee"
        android:singleLine="true"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/contact_number"
        android:layout_width="fill_parent"
        android:layout_height="0dip"
        android:layout_weight="1"
        android:ellipsize="marquee"
        android:singleLine="true" />
</LinearLayout>

</LinearLayout>

这是数据库

public class CardsDatabase {

public static String USERTEMPLATE = "user";
public static String MYCARD = "mycard";
public static String ALERT = "alert";

public static String USER = "user";
public static String NAME = "name";
public static String COMPANY = "company";
public static String TITLE = "title";
public static String ADDRESS = "address";
public static String PHONE = "phone";
public static String CEL = "cel";
public static String EMAIL = "email";
public static String PHOTO = "photo";

public static String ROW_R = "_id";
public static String NAME_R = "rname";
public static String COMPANY_R = "rcompany";
public static String TITLE_R = "rtitle";
public static String ADDRESS_R = "raddress";
public static String PHONE_R = "rphone";
public static String CEL_R = "rcel";
public static String EMAIL_R = "remail";
public static String PHOTO_R = "rphoto";
public static String TEMPLATE_R = "rtemplate";

public static String MAC = "macaddress";

private static String DATABASE_NAME = "CardsDatabase";
public static String DATABASE_TABLE_TEMPLATE = "TemplateTable";
public static String DATABASE_TABLE_MYTABLE = "MYTable";
public static String DATABASE_TABLE_CONTACTS = "ContactsTable";
public static String DATABASE_TABLE_CONTACTS_REMOTE = "rContactsTable";

private static int DATABASE_VERSION = 1;

private DbHelper ourHelper;
private final Context ourContext;
private SQLiteDatabase ourDatabase;

private static class DbHelper extends SQLiteOpenHelper {

    public DbHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        // TODO Auto-generated constructor stub
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        // Log.d(Tag,"Inner on create called");
        db.execSQL("CREATE TABLE " + DATABASE_TABLE_TEMPLATE + " ("
                + USERTEMPLATE + " TEXT NOT NULL," + MYCARD
                + " TEXT NOT NULL," + ALERT + " TEXT NOT NULL" + ");");

        db.execSQL("CREATE TABLE " + DATABASE_TABLE_MYTABLE + " (" + USER
                + " TEXT NOT NULL," + NAME + " TEXT NOT NULL," + COMPANY
                + " TEXT," + TITLE + " TEXT," + ADDRESS + " TEXT," + PHONE
                + " TEXT NOT NULL," + CEL + " TEXT," + EMAIL
                + " TEXT NOT NULL," + PHOTO + " BLOB" + ");");

        db.execSQL("CREATE TABLE " + DATABASE_TABLE_CONTACTS_REMOTE + " ("
                + ROW_R + " integer primary key autoincrement," + NAME_R
                + " TEXT NOT NULL," + COMPANY_R + " TEXT," + TITLE_R
                + " TEXT," + ADDRESS_R + " TEXT," + TEMPLATE_R
                + " TEXT NOT NULL," + PHONE_R + " TEXT NOT NULL," + CEL_R
                + " TEXT," + EMAIL_R + " TEXT NOT NULL," + PHOTO_R
                + " BLOB" + ");");

        db.execSQL("CREATE TABLE " + DATABASE_TABLE_CONTACTS + " (" + MAC
                + " TEXT NOT NULL" + ");");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        db.execSQL("DROP TABLE IF EXISTS" + DATABASE_TABLE_TEMPLATE);
        db.execSQL("DROP TABLE IF EXISTS" + DATABASE_TABLE_MYTABLE);
        db.execSQL("DROP TABLE IF EXISTS" + DATABASE_TABLE_CONTACTS);
        db.execSQL("DROP TABLE IF EXISTS" + DATABASE_TABLE_CONTACTS_REMOTE);

        onCreate(db);
    }

}

public CardsDatabase(Context c) {
    ourContext = c;
}

public CardsDatabase open() throws SQLException {
    ourHelper = new DbHelper(ourContext);
    ourDatabase = ourHelper.getWritableDatabase();
    return this;
}

public void close() {
    ourHelper.close();
}

public void createEntry(int type, ContentValues cv) {
    // TODO Auto-generated method stub

    switch (type) {
    case 1:
        ourDatabase.insert(DATABASE_TABLE_TEMPLATE, null, cv);
        break;
    case 2:
        ourDatabase.insert(DATABASE_TABLE_MYTABLE, null, cv);
        break;
    case 3:
        ourDatabase.insert(DATABASE_TABLE_CONTACTS, null, cv);
        break;
    case 4:
        ourDatabase.insert(DATABASE_TABLE_CONTACTS_REMOTE, null, cv);
        break;
    }

}

public Cursor getTemplate() throws SQLException {
    // TODO Auto-generated method stub

    String[] columns = new String[] { USERTEMPLATE, MYCARD, ALERT };

    Cursor c = ourDatabase.query(DATABASE_TABLE_TEMPLATE, columns, null,
            null, null, null, null);

    return c;
}

public Cursor getMyData() throws SQLException {
    // TODO Auto-generated method stub

    String[] columns = new String[] { USER, NAME, COMPANY, TITLE, ADDRESS,
            PHONE, CEL, EMAIL, PHOTO };

    Cursor c = ourDatabase.query(DATABASE_TABLE_MYTABLE, columns, null,
            null, null, null, null);

    return c;
}

public Cursor geTContactsData() throws SQLException {
    // TODO Auto-generated method stub

    String[] columns = new String[] { ROW_R, NAME_R, PHONE_R};

    Cursor c = ourDatabase.query(DATABASE_TABLE_CONTACTS_REMOTE, columns,
            null, null, null, null, null);

    return c;
}

public Cursor getDetailData(int row_id) {

    String WHERE = String.format("%s='%d'", ROW_R, row_id);
    String[] columns = new String[] { NAME_R, TITLE_R, ADDRESS_R, PHONE_R,
            CEL_R, EMAIL_R, TEMPLATE_R, PHOTO_R };

    Cursor c = ourDatabase.query(DATABASE_TABLE_CONTACTS_REMOTE, columns,
            WHERE, null, null, null, null);

    return c;
}

public boolean contactExist(String mac_adr) throws SQLException {
    // TODO Auto-generated method stub

    String[] columns = new String[] { MAC };

    String WHERE = String.format("%s='%s'", MAC, mac_adr);
    Cursor c = ourDatabase.query(DATABASE_TABLE_CONTACTS, columns, WHERE,
            null, null, null, null);

    return c.getCount() > 0 ? true : false;
}

public void updateTemplate(ContentValues cv) {
    String m = "me";
    String WHERE = String.format("%s='%s'", USERTEMPLATE, m);
    ourDatabase.update(DATABASE_TABLE_TEMPLATE, cv, WHERE, null);
}

public void updateMytable(ContentValues cv) {
    String m = "me";
    String WHERE = String.format("%s='%s'", USERTEMPLATE, m);
    ourDatabase.update(DATABASE_TABLE_MYTABLE, cv, WHERE, null);
}
}

Logcat显示此

02-28 09:18:09.702: D/cursor length(5152): 10

Answer 1

在onCreate（）中设置适配器后，从代码中删除cursor.close();。

SimpleCursorAdaptor不显示数据

1 个答案: