Question

我有一个电视应用程序。我看到频道列表，我就像一排。但现在我想把它重写成一个网格。我正在尝试设置网格展示器，但它不起作用它说我必须实现MainFragmentAdapterProvider。并且教程中的所有提示也不起作用，我无法弄清楚什么是问题。也许还有另一位主持人呢？

    public class ChannelsFragment extends RowsFragment implements OnItemViewClickedListener {

    private ArrayObjectAdapter mRowsAdapter = new ArrayObjectAdapter(new ListRowPresenter());
    //private ArrayObjectAdapter mRowsAdapter;
    private IServiceControl mServiceControl;

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

        mServiceControl = ((A4TVTestApp) getActivity().getApplication()).getServiceControl();

        setAdapter(mRowsAdapter);
        setOnItemViewClickedListener(this);

        createRows();
    }

    private void createRows() {
//        VerticalGridPresenter presenter = new VerticalGridPresenter();
//        presenter.setNumberOfColumns(4);
//        setGridPresenter(presenter);
//        setTitle(getString(R.string.scanned_channels));
//
//        setOnItemViewClickedListener(this);
//
//        try {
//            for (int i = 0; i < mServiceControl.getServiceListCount(0); i++) {
//                mRowsAdapter.add(mServiceControl.getServiceDescriptor(0, i).getName());
//            }
//        } catch (RemoteException e) {
//            e.printStackTrace();
//        }
        ChannelsRowItemPresenter presenter = new ChannelsRowItemPresenter();

        ArrayObjectAdapter firstRowAdapter = new ArrayObjectAdapter(presenter);
        ArrayObjectAdapter secondRowAdapter = new ArrayObjectAdapter(presenter);
        ArrayObjectAdapter thirdRowAdapter = new ArrayObjectAdapter(presenter);
        ArrayObjectAdapter fourthRowAdapter = new ArrayObjectAdapter(presenter);

        try {
            int count = mServiceControl.getServiceListCount(0);
            for (int i = 0; i < count; i += 4) {
                firstRowAdapter.add(mServiceControl.getServiceDescriptor(0, i));
                secondRowAdapter.add(mServiceControl.getServiceDescriptor(0, i + 1));
                thirdRowAdapter.add(mServiceControl.getServiceDescriptor(0, i + 2));
                fourthRowAdapter.add(mServiceControl.getServiceDescriptor(0, i + 3));
            }
        } catch (RemoteException e) {
            e.printStackTrace();
        }

        mRowsAdapter.add(new ListRow(new HeaderItem(getString(R.string.scanned_channels)),
                firstRowAdapter));

        mRowsAdapter.add(new ListRow(secondRowAdapter));
        mRowsAdapter.add(new ListRow(thirdRowAdapter));
        mRowsAdapter.add(new ListRow(fourthRowAdapter));
    }

    @Override
    public void onItemClicked(Presenter.ViewHolder itemViewHolder, Object item,
                              RowPresenter.ViewHolder rowViewHolder, Row row) {
        ServiceDescriptor serviceDescriptor = (ServiceDescriptor) item;
        ChannelActivity.startActivity(getActivity(), serviceDescriptor.getLCN());
    }
}

Answer 1

您是否尝试过扩展VerticalGridFragment？

leanback样本中有一个例子： https://github.com/googlesamples/androidtv-Leanback/blob/master/app/src/main/java/com/example/android/tvleanback/ui/VerticalGridFragment.java

您的实施应类似于以下内容。 MyPresenter应该是Presenter的子类，例如leanback中的CardPresenter，它通过扩展BaseCardView来委托/管理像ImageCardView或您的自定义卡视图这样的视图。如果您有更多动态内容，请改为使用PresenterSelector，以便每张卡可以不同。

public class ChannelFragment extends android.support.v17.leanback.app.VerticalGridFragment
implements OnItemViewClickedListener {

    private static final int NUM_COLUMNS = 5;

    private final ArrayObjectAdapter mRowsAdapter;
    private IServiceControl mServiceControl;


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

        mRowsAdapter = new ArrayObjectAdapter(new MyPresenter());
        mServiceControl = ((A4TVTestApp) getActivity().getApplication()).getServiceControl();
        setAdapter(mRowsAdapter);
        setOnItemViewClickedListener(this);

        createRows();
    }

    private void createRows() {
        VerticalGridPresenter gridPresenter = new VerticalGridPresenter();
        gridPresenter.setNumberOfColumns(NUM_COLUMNS);
        // This is the method that will help you get a grid layout.
        setGridPresenter(gridPresenter);

        setOnItemViewClickedListener(this);

        try {
            for (int i = 0; i < mServiceControl.getServiceListCount(0); i++) {
                mRowsAdapter.add(i);
            }
        } catch (RemoteException e) {
             e.printStackTrace();
        }

    }


    @Override
    public void onItemClicked(Presenter.ViewHolder itemViewHolder, Object item,
                      RowPresenter.ViewHolder rowViewHolder, Row row) {
         ChannelActivity.startActivity(getActivity(), (int) item);
    }
}

Answer 2

还有一个method on ListRowAdapter可以启用每行多行。

ListRowPresenter presenter = new ListRowPresenter()
presenter.setNumRows(4)
ArrayObjectAdapter mRowsAdapter = new ArrayObjectAdapter(presenter);

这比使用VerticalGridFragment更好，具体取决于您是否仍需要类别标题。

如何将通道列表替换为网格列表？

2 个答案: