Question

我有一个扩展ListFragment的类，我正在使用支持库。在类的onListItemClick方法中，我有这一行：

@Override
public void onListItemClick(ListView l, View v, int position, long id) {
    String item = (String) ((Fragment) getListAdapter().getItem(position)).getString(1);
    DetailFrag frag = (DetailFrag) getFragmentManager().findFragmentById(R.id.frag_stitchdetail);
    if (frag != null && frag.isInLayout()) {
        frag.setText(item);
    }
}

其中position是传递给onListItemClick方法的参数。对于我正在构建的示例应用程序，它在运行时的值为0，因为列表中只有一个项目。该行引发以下错误：

java.lang.CastClassException：android.content.ContentResolver $ CursorWrapperInner无法强制转换为java.lang.String

我已经用Google搜索并搜索了stackoverflow，但是我没有看到任何可以提示我为何无法将其转换为String的提示。谁知道？谢谢！

我的查询的ContentProvider代码：

@Override
public Cursor query(Uri uri, String[] projection, String selection,
        String[] selectionArgs, String sortOrder) {
    SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
    queryBuilder.setTables(STITCHTABLE_BASEPATH);
    int uriType = sURIMatcher.match(uri);
    switch (uriType)
    {
    case STITCHES_ID:
        queryBuilder.appendWhere(SQLData.KEY_ROWID + "=" + uri.getLastPathSegment());
        break;
    case STITCHES:
        //no filter
        break;
    default:
        throw new IllegalArgumentException("Unknown URI");
    }
    Cursor cursor = queryBuilder.query(mDB.getReadableDatabase(), projection, selection, selectionArgs, null, null, sortOrder);
    cursor.setNotificationUri(getContext().getContentResolver(), uri);
    return cursor;
}

我的ListFragment中CursorLoader的代码：

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

    Intent myData = getActivity().getIntent();
    Bundle info = myData.getExtras();

    String[] dataColumns = { "stitchname" };
    int[] viewIDs = { R.id.stitchlist1 };
    mAdapter = new SimpleCursorAdapter(getActivity(), R.layout.stitchlist, null, dataColumns, viewIDs, 0);
    setListAdapter(mAdapter);
    getLoaderManager().initLoader(0, info, (LoaderCallbacks<Cursor>) this); 

}
@Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
    String selection = "stitchlevel=?";
    String[] selectionArgs = new String[] {args.getString("Level")};
    return (Loader<Cursor>) new CursorLoader(getActivity(), STITCHES_URI,
            PROJECTION, selection, selectionArgs, null);    
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
        mAdapter.swapCursor((android.database.Cursor) cursor);      
}

在ListFragment的onListItemClick方法中获取CastClassException错误

0 个答案: