4

这是我第一次测试 SimpleCursorAdapter。我想将它与 ORMLite 一起使用。

不幸的是，我总是得到 StaleDataException :(

编辑： 不知道adapter.swapCursor(c) 是否是问题所在。跨过那个没有问题。问题似乎出在其他地方/END EDIT

该错误似乎发生在 adapter.swapCursor(c) 中。c 已关闭，这似乎是问题所在，我该如何解决这个问题，为什么它到底是关闭的？注意：仅当 Einsatz1 sqllite 表包含数据时才会发生错误。如果桌子是空的，一切都会完美运行。

这是我的活动：

public class UebersichtEinsaetze extends FragmentActivity implements LoaderManager.LoaderCallbacks<Cursor>
{
...

  public DatabaseHelper helper = null;

  @Override
  protected void onDestroy()
  {
    super.onDestroy();
    ((SimpleCursorAdapter) einsatzListView.getAdapter()).getCursor().close();
    helper.close();
    if (helper != null)
    {
      OpenHelperManager.releaseHelper();
      helper = null;
    }

  }

  private DatabaseHelper getHelper()
  {
    if (helper == null)
    {
      helper = OpenHelperManager.getHelper(this, DatabaseHelper.class);
    }
    return helper;
  }

  @Override
  public void onCreate(Bundle savedInstanceState)
  {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_ubersicht_einsaetze);
    einsatzListView = (ListView) findViewById(android.R.id.list);
    einsatzDatumTextView = (TextView) findViewById(R.id.tv_uebersicht_abdatum);
    fillData();
    getHelper();
  }

  private void fillData()
  {
    String[] from = new String[] { "_id" };
    int[] to = new int[] { R.id.view_list_einsatz_text_projnr };

    adapter = new SimpleCursorAdapter(this, R.layout.view_list_eintrag_einsatz, null, from, to, 0);
    getSupportLoaderManager().initLoader(0, null, this);
    einsatzListView.setAdapter(adapter);
  }

  @Override
  public Loader<Cursor> onCreateLoader(int id, Bundle args)
  {
    String[] projection = { "_id" };
    CursorLoader cursorLoader = new CursorLoader(this, test.CONTENT_URI, projection, null, null, null);
    return cursorLoader;
  }

  @Override
  public void onLoadFinished(Loader<Cursor> loader, Cursor c)
  {
    adapter.swapCursor(c);
  }

  @Override
  public void onLoaderReset(Loader<Cursor> loader)
  {
    adapter.swapCursor(null);
  }
}

这是我的内容提供者：

 private DatabaseHelper database;
  private RuntimeExceptionDao<Einsatz1, String> dao;

  // Used for the UriMacher
  private static final int EINSAETZE = 10;
  private static final int EINSATZ_ID = 20;

  private static final String AUTHORITY = "de.myapp.android";

  private static String BASE_PATH = "einsaetze";
  public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/" + BASE_PATH);

  public static final String CONTENT_TYPE = ContentResolver.CURSOR_DIR_BASE_TYPE + "/einsaetze";
  public static final String CONTENT_ITEM_TYPE = ContentResolver.CURSOR_ITEM_BASE_TYPE + "/einsatz";

  private static final UriMatcher sURIMatcher = new UriMatcher(UriMatcher.NO_MATCH);
  static
  {
    sURIMatcher.addURI(AUTHORITY, BASE_PATH, EINSAETZE);
    sURIMatcher.addURI(AUTHORITY, BASE_PATH + "/#", EINSATZ_ID);
  }

@Override
  public boolean onCreate()
  {
    database = new DatabaseHelper(getContext());
    this.dao = (RuntimeExceptionDao<Einsatz1, String>) database.getRTE(Einsatz1.class);
    return false;
  }

@Override
  public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder)
  {
    // ignore method parameters for now just to get it basically working

    QueryBuilder<Einsatz1, String> queryBuilder = this.dao.queryBuilder();

    Cursor cursor = null;
    CloseableIterator<Einsatz1> iterator = null;
    try
    {
      iterator = dao.iterator(queryBuilder.prepare());
      AndroidDatabaseResults results = (AndroidDatabaseResults) iterator.getRawResults();
      cursor = results.getRawCursor();
    }
    catch (SQLException e)
    {
      Log.e(getClass().getName(), "get cursor", e);
    }
    finally
    {
      iterator.closeQuietly();
    }

    // Make sure that potential listeners are getting notified
    cursor.setNotificationUri(getContext().getContentResolver(), uri);

    return cursor;
  }

日志猫：

01-09 10:01:29.591: E/AndroidRuntime(3767): FATAL EXCEPTION: main
01-09 10:01:29.591: E/AndroidRuntime(3767): android.database.StaleDataException: Attempting to access a closed CursorWindow.Most probable cause: cursor is deactivated prior to calling this method.
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:139)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:50)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.database.CursorWrapper.getString(CursorWrapper.java:114)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.support.v4.widget.SimpleCursorAdapter.bindView(SimpleCursorAdapter.java:135)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.support.v4.widget.CursorAdapter.getView(CursorAdapter.java:256)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.widget.AbsListView.obtainView(AbsListView.java:2267)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.widget.ListView.measureHeightOfChildren(ListView.java:1244)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.widget.ListView.onMeasure(ListView.java:1156)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.View.measure(View.java:15172)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.widget.RelativeLayout.measureChild(RelativeLayout.java:602)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:415)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.View.measure(View.java:15172)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.View.measure(View.java:15172)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.widget.LinearLayout.measureVertical(LinearLayout.java:833)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.View.measure(View.java:15172)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2148)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.View.measure(View.java:15172)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1848)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1100)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1273)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:998)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4212)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.Choreographer.doCallbacks(Choreographer.java:555)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.Choreographer.doFrame(Choreographer.java:525)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.os.Handler.handleCallback(Handler.java:615)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.os.Handler.dispatchMessage(Handler.java:92)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.os.Looper.loop(Looper.java:137)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at android.app.ActivityThread.main(ActivityThread.java:4745)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at java.lang.reflect.Method.invokeNative(Native Method)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at java.lang.reflect.Method.invoke(Method.java:511)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
01-09 10:01:29.591: E/AndroidRuntime(3767):     at dalvik.system.NativeStart.main(Native Method)

小提示（不重要，但如果有人有信息...）：当我在 adapter.swapCursor(c) 之前设置断点时，它不会在抛出错误之前停止。我必须设置一个断点来在该语句之前插入一个虚拟的“int bla = 123”。类似地，在 public Cursor query(...) 方法中的任何位置设置断点可以使一切执行都没有错误（到底是什么...），但又不会在断点处停止。

4

2 回答 2

4

解决了

注释掉

iterator.closeQuietly();

即使我找到了来自这里的代码：

在 CursorAdapter 中使用带有 ORMLite 的 Android 游标

...你不应该依赖它。

我将不得不看看注释掉会有什么潜在的负面后果（如果有人知道请告诉我），但现在一切似乎都在起作用。

于 2013-01-09T11:43:53.053 回答
1

是的，它看起来是由于 iterator.closeQuietly() 造成的，尽管注释掉的影响是您现在可能会在打开许多迭代器的情况下发生泄漏（实际上应该关闭）。

相反，在您的 onQuery() 方法中，尝试使用以下内容，这将为您提供对 Cursor 的引用，当您的 ContentProvider 关闭时，它应该关闭。

Cursor cursor = getHelper().getReadableDatabase().query(tableName, projection, selection, selectionArgs, groupBy, having, sortOrder)
于 2013-06-22T12:36:17.083 回答