Android TV Leanback (七)（详情视图）

创建一个详情presenter

Leanback library提供了视频浏览框架，你可以使用presenter控制数据在屏幕上的显示，包括视频详情。这个框架为止提供了AbstractDetailsDescriptionPresenter，你需要实现onBindDescription()，将数据与视图绑定。如下：

public class DetailsDescriptionPresenterextends AbstractDetailsDescriptionPresenter {
    @Override
    protected void onBindDescription(ViewHolder viewHolder, Object itemData) {
        MyMediaItemDetails details = (MyMediaItemDetails) itemData;

        // itemData包含视频的详细信息
        //需要显示视频的详细信息
        // viewHolder.getTitle().setText(details.getShortTitle());

        // 使用静态数据测试：
        viewHolder.getTitle().setText(itemData.toString());
        viewHolder.getSubtitle().setText("2014   Drama   TV-14");
        viewHolder.getBody().setText("Lorem ipsum dolor sit amet, consectetur "
            + "adipisicing elit, sed do eiusmod tempor incididunt ut labore "
            + " et dolore magna aliqua. Ut enim ad minim veniam, quis "
            + "nostrud exercitation ullamco laboris nisi ut aliquip ex ea "
            + "commodo consequat.");
    }
}

继承DetailsFragment

使用DetailsFragment来显示视频的详细信息，它提供额外的内容，比如：预览图片，关于视频的操作项（购买、播放、关注等）。您还可以提供额外的内容，如相关视频或演员的列表。如下：

public class MediaItemDetailsFragment extends DetailsFragment {

    private static final String TAG = "MediaItemDetailsFragment";
    private ArrayObjectAdapter mRowsAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        Log.i(TAG, "onCreate");
        super.onCreate(savedInstanceState);
        buildDetails();
    }

    private void buildDetails() {
        ClassPresenterSelector selector = new ClassPresenterSelector();
    
        // 将视频详细信息的presenter附加到rowPresenter上
        FullWidthDetailsOverviewRowPresenter rowPresenter =
            new FullWidthDetailsOverviewRowPresenter(
                new DetailsDescriptionPresenter());

        selector.addClassPresenter(DetailsOverviewRow.class, rowPresenter);
        selector.addClassPresenter(ListRow.class,
                new ListRowPresenter());
        mRowsAdapter = new ArrayObjectAdapter(selector);

        Resources res = getActivity().getResources();
        DetailsOverviewRow detailsOverview = new DetailsOverviewRow(
                "Media Item Details");
   
        // 给详情视图添加图片和操作
        detailsOverview.setImageDrawable(res.getDrawable(R.drawable.jelly_beans));
        detailsOverview.addAction(new Action(1, "Buy $9.99"));
        detailsOverview.addAction(new Action(2, "Rent $2.99"));
        mRowsAdapter.add(detailsOverview);

   
        // 添加相关项
        ArrayObjectAdapter listRowAdapter = new ArrayObjectAdapter(
            new StringPresenter());
        listRowAdapter.add("Media Item 1");
        listRowAdapter.add("Media Item 2");
        listRowAdapter.add("Media Item 3");
        HeaderItem header = new HeaderItem(0, "Related Items", null);
        mRowsAdapter.add(new ListRow(header, listRowAdapter));
        setAdapter(mRowsAdapter);
    }
}

创建详情Activity

创建一个activity包含DetailsFragment来显示详情。

创建布局:

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    android:name="com.example.android.mediabrowser.MediaItemDetailsFragment"
    android:id="@+id/details_fragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

创建Activity：

public class DetailsActivity extends Activity{

     @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.details);
    }
}

注册：

<application>
  ...
  <activity android:name=".DetailsActivity"
    android:exported="true"
    android:theme="@style/Theme.Leanback"/>
</application>

定义一个Listener监听每项的点击

public class BrowseMediaActivity extends Activity {
    ...

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        ...

        // create the media item rows
        buildRowsAdapter();

        // add a listener for selected items
        mBrowseFragment.OnItemViewClickedListener(
            new OnItemViewClickedListener() {
                @Override
                public void onItemClicked(Object item, Row row) {
                    System.out.println("Media Item clicked: " + item.toString());
                    Intent intent = new Intent(BrowseMediaActivity.this,
                        DetailsActivity.class);
                    // pass the item information
                    intent.getExtras().putLong("id", item.getId());
                    startActivity(intent);
                }
            });
    }
}