Question

我的Android应用程序中有一个带有自定义ListFragment的怪异内容。我有ArrayAdapter的自定义listView由LoaderManager处理，除此之外我还附加了headerView：

public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    setListAdapter(null);
}

public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    if (getListView().getHeaderViewsCount() <= 0 && headerView != null)

        getListView().addHeaderView(headerView, null, false);

            if (listAdapter == null)
    listAdapter = new DataAdapter(getActivity(), R.id.label1,
            (CategoryModel) getArguments().getParcelable(MODEL_KEY));
    setListAdapter(listAdapter);

    setListShown(false);
    getLoaderManager().initLoader(0, null, this);

     }



    private final static class DataAdapter extends ArrayAdapter<ICatalogModel> {
        private final LayoutInflater inflater;
        private final CategoryModel parentModel;

        private CustomArrayFilter filter;

        public DataAdapter(Context c, int textViewResourceId,
                CategoryModel parentModel) {
            super(c, textViewResourceId);
            this.parentModel = parentModel;
            inflater = LayoutInflater.from(c);
        }

        @Override
        public boolean areAllItemsEnabled() {
            return true;
        }

        @Override
        public boolean isEnabled(int position) {
            return true;
        }



        public ArrayList<ICatalogModel> getData() {
            return originalValues;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View v = convertView;
            ItemHolder holder;
            if (v == null) {
                v = inflater.inflate(R.layout.rooms_list_row, parent, false);
                holder = new ItemHolder();
                holder.nameField = (TextView) v.findViewById(R.id.label1);
                v.setTag(holder);
            }

            holder = (ItemHolder) v.getTag();

            final ICatalogModel model = getItem(position);
            holder.nameField.setText(model.getName());
            return v;
        }

        public void addAllSupport(ArrayList<ICatalogModel> data) {
            for (ICatalogModel p : data) {
                add(p);
            }
            notifyDataSetChanged();
        }
}

在onLoaderReset方法上，我试图通过调用myAdapter.clear()来清除适配器的数据，但是在第126行的android IndexOutOfBounds类中抛出了一个奇怪的HeaderViewListAdapter异常：< / p>

@Override
public void onLoaderReset(Loader<ArrayList<ICatalogModel>> arg0) {
    if (listAdapter != null) {
            ((DataAdapter) listAdapter).clear();
    }
}

@Override
public void onLoadFinished(Loader<ArrayList<ICatalogModel>> arg0,
        ArrayList<ICatalogModel> arg1) {

    if (listAdapter != null) {
        ((DataAdapter) listAdapter).clear();
        if (CokConstants.SUPPORTS_HONEYCOMB) {
            ((DataAdapter) listAdapter).addAll(arg1);
        } else {
            ((DataAdapter) listAdapter).addAllSupport(arg1);
        }
        ((DataAdapter) listAdapter).setOriginalValues(arg1);
    }
    if (isResumed())
        setListShown(true);
    else
        setListShownNoAnimation(true);
}

我认为这个问题在某种程度上与我在headerView方法中删除onDestroyView这一事实有关...我做到了......没有例外......但现在又出现了另一个问题......每当我从backstack回到那个片段时......只要数据在适配器中正确添加，该列表就不再可见了。有没有人遇到过这个问题？

Answer 1

向ListView添加页眉或页脚视图时;您设置的适配器被包装到WrapperListAdapter中。您必须检查适配器的实例。

DataAdapter myExistingAdapter = null;
if(listAdapter instanceof WrapperListAdapter) {
    myExistingAdapter = (DataAdapter)((WrapperListAdapter)listAdapter).getWrappedAdapter();
} else if (listAdapter instanceof DataAdapter) {
    myExistingAdapter = (DataAdapter)listAdapter;
}

android.widget.WrapperListAdapter 已知的间接子类 HeaderViewListAdapter

带有headerview的Android ListView

1 个答案: