Question

在Main activity我有一个listview，用SimpleCursorAdapter填充frome数据库。当我点击listview item发送项目ID并打开包含edit activity字段的edittext时。

那么，我如何从数据库加载数据到edittext？

主要活动：

 public class MainScreen extends FragmentActivity implements OnClickListener {

  final String LOG_TAG = "myLogs";
  ListView listViewMain;
  ImageButton addButton;
  CheckBox deleteCheck;
  SQLiteDatabase db;
  DataBase DB;
  DBHelper dbHelper;
  Cursor cursor;
  SimpleCursorAdapter passListViewAdapter;
  long itemId;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
        setContentView(R.layout.main_screen);

        listViewMain = (ListView) findViewById(R.id.listViewMain);
        listViewMain.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                int itemSelected = position;
                if (position == itemSelected){
                    Intent intentId = new Intent(MainScreen.this, ViewListItem.class);
                    intentId.putExtra("itemId", id);
                    Log.d(LOG_TAG, "add button : " + id);
                    startActivity(intentId);
                }
            }
        });
}

@Override
protected void onResume() {
    super.onResume();
    loaderAdapter();
}

public void loaderAdapter(){
    DB = new DataBase(this);

    String[] from = new String[] { DataBase.COLUMN_TITLE,  DataBase.COLUMN_DATE};

    int[] to = new int[] { R.id.titleView, R.id.dateView };
    passListViewAdapter = new SimpleCursorAdapter(
            this, 
            R.layout.item, 
            DB.fetchAllPass(), 
            from, 
            to
             , SimpleCursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);

    listViewMain.setAdapter(passListViewAdapter);
}}

数据库活动：

     public class DataBase {
  public static final String DB_NAME = "appdb";
  public static final int DB_VERSION = 1;
  static final String TABLE_NAME = "passtab";
  final String LOG_TAG = "myLogs";
  public static final String COLUMN_ID = "_id";
  public static final String COLUMN_TITLE = "title_enter";
  public static final String COLUMN_LOGIN = "login_enter";
  public static final String COLUMN_PASSWORD = "password_enter";
  public static final String COLUMN_URL = "link_enter";
  public static final String COLUMN_COMMENT = "comment_enter";
  public static final String COLUMN_DATE = "date_enter";
  public String results;
  private DBHelper dbHelper;
  private static Context mContext;
  private SQLiteDatabase db;

  private static final String DB_CREATE = 
            "create table " + TABLE_NAME + "(" +
              COLUMN_ID + " integer primary key autoincrement, " +
              COLUMN_TITLE + " VARCHAR(255), " +
              COLUMN_LOGIN + " VARCHAR(255), " +
              COLUMN_PASSWORD + " VARCHAR(255), " +
              COLUMN_URL + " VARCHAR(255), " +
              COLUMN_COMMENT + " text, " +
              COLUMN_DATE + " VARCHAR(255)" +
            ");";

     public class DBHelper extends SQLiteOpenHelper{


      public DBHelper(Context context) {
            super(context, DB_NAME, null, DB_VERSION);
          }

        @Override
      public void onCreate(SQLiteDatabase sqLiteDatabase) {
        sqLiteDatabase.execSQL(DB_CREATE);
      }

      @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        }


}

 public DataBase(Context c) {
 mContext = c;
 }

 public DataBase open() throws SQLiteException {
 Log.d(LOG_TAG, "opening with cacheword");
 dbHelper = new DBHelper(mContext);

 db = dbHelper.getWritableDatabase();

 System.gc();
 return this;
 }

 public boolean isOpen (){
if (db !=null)
    return db.isOpen();
else
    return false;
 }

 public SQLiteDatabase getDatabase() {
 return db;
 }

 public void close() {
 if( dbHelper != null )
    dbHelper.close();
 }

     public Cursor fetchPass(long rowId) throws SQLException {
     openGuard();
     Cursor mCursor = db.query(TABLE_NAME, new String[] {COLUMN_TITLE, COLUMN_LOGIN, COLUMN_PASSWORD, COLUMN_URL, COLUMN_DATE}, COLUMN_ID + "=" + rowId, null, null, null, null, null);
   if (mCursor != null) {
    mCursor.moveToFirst();
   }
    return mCursor;

   }

private void openGuard() throws SQLiteException {
if(isOpen()) return;
open();
if(isOpen()) return;
Log.d(LOG_TAG, "open guard failed");
throw new SQLiteException("Could not open database");
}}

第二项活动：

public class ViewListItem extends MainScreen implements OnClickListener{
final String LOG_TAG = "myLogs";
EditText comment_enter, link_enter, password_enter, login_enter, title_enter, date_enter;
Button delete_button, clear_close_button, save_changes_item_button;
CheckBox editCheck;
DBHelper db;
DataBase DB;
SimpleCursorAdapter passListViewAdapter;
SimpleDateFormat sdf;
private Cursor cursor = null;
long itemSelected;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.view_item);

    Intent intentId = getIntent();
    long itemSelected = intentId.getLongExtra("itemId", 1);
    Log.d(LOG_TAG, "received id : " + itemSelected);
    cursor = DB.fetchPass(itemSelected);
    String[] nnn = cursor;
    comment_enter = (EditText) findViewById(R.id.comment_enter);
    link_enter = (EditText) findViewById(R.id.link_enter);
    password_enter = (EditText) findViewById(R.id.password_enter);
    login_enter = (EditText) findViewById(R.id.login_enter);
    title_enter = (EditText) findViewById(R.id.title_enter);
    date_enter = (EditText) findViewById(R.id.date_enter);
}

@Override
  protected void onPause() {
    super.onPause();
    finish();
    Log.d(LOG_TAG, "onPause : ");
  }

}

Answer 1

我接下来解决这个问题：在第二个活动中改变这一行：

cursor = DB.fetchPass(itemSelected);
String[] nnn = cursor;

为：

Cursor c = DB.fetchPass(itemSelected);

然后从光标中弹出每个字符串：

   String title_str = c.getString(c.getColumnIndex("title_enter"));
   String login_str = c.getString(c.getColumnIndex("login_enter"));
   String pass_str = c.getString(c.getColumnIndex("password_enter"));
   String link_str = c.getString(c.getColumnIndex("link_enter"));
   String comment_str = c.getString(c.getColumnIndex("comment_enter"));
   String date_str = c.getString(c.getColumnIndex("date_enter"));

收到的字符串设置为EditText字段。

如何使用edittext字段将数据从数据库加载到Edit活动？

1 个答案: