如何在片段内显示不同的布局

Question

我在Android Honeycomb（Tab）中处理两个片段。左边是ListView，右边是从列表中选择的项目的预览。单击其中一个按钮时，我想在左侧显示不同的布局。这怎么可能？

提前致谢。

Answer 1

你可以这样做，我使用这些链接做了同样的事情，这是我与你分享的代码，希望它对你有所帮助......你首先必须创建4个布局。其中2个用于横向模式，一个用于纵向模式，另一个用于平板电脑。您必须为布局创建更多文件夹，其名称应为layout-xlarge和layout-xlarge-port，这样您就可以为移动设备和平板电脑创建片段。

MasterFragment活动：

public class MasterFragment extends ListFragment {
    Boolean isDualPane;
    int position;

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        ArrayList<String> parkNames = new ArrayList<String>();
        for (Park park : Resort.PARKS) {
            parkNames.add(park.getName());
        }

        setListAdapter(new ArrayAdapter<String>(getActivity(),
                android.R.layout.simple_list_item_1, parkNames));
        View detailFrame = getActivity().findViewById(R.id.detail);
        isDualPane = detailFrame != null && detailFrame.getVisibility() == View.VISIBLE;

        if (savedInstanceState != null) {
            position = savedInstanceState.getInt("position", 0);
        }

        if (isDualPane) {
            getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE);
            showDetail(position);
        }
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt("position", position);
    }

    @Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        showDetail(position);
    }

    void showDetail(int position) {
        this.position = position;
        if (isDualPane) {
            getListView().setItemChecked(position, true);
            DetailFragment detailFragment = (DetailFragment) getFragmentManager()
                    .findFragmentById(R.id.detail);

            if (detailFragment == null || detailFragment.getIndex() != position) {
                detailFragment = new DetailFragment(position);
                FragmentTransaction ft = getFragmentManager()
                        .beginTransaction();
                ft.replace(R.id.detail, detailFragment);
                ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
                ft.commit();
            }
        } else {
            Intent intent = new Intent();
            intent.setClass(getActivity(), DetailActivity.class);
            intent.putExtra("position", position);
            startActivity(intent);
        }
    }
}        

第二项活动 - DetailFragment活动：

public class DetailActivity extends FragmentActivity {

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

        setContentView(R.layout.detail_act);
        Bundle bundle = getIntent().getExtras();
        int position = bundle.getInt("position");
        System.out.println("RR : position is : " + position);

        Integer[] images = { R.drawable.pic1, R.drawable.pic2, R.drawable.pic3,
                R.drawable.pic4, R.drawable.pic5, R.drawable.pic6,
                R.drawable.pic7, R.drawable.pic8, R.drawable.pic9,
                R.drawable.pic10, R.drawable.pic11, R.drawable.pic12,
                R.drawable.pic13 };

        final ImageView imgview = (ImageView) findViewById(R.id.imageView1);
        imgview.setImageResource(images[position]);

        // DetailFragment detailFragment = new DetailFragment(position);
        // FragmentManager fm = getSupportFragmentManager();
        // FragmentTransaction ft =fm.beginTransaction();
        // ft.add(android.R.id.content, detailFragment).commit();

    }
}

现在您必须为我的图片创建第三个活动MasterGridActivity，我用它来显示GridView中的片段。

public class MasterGridActivity extends Fragment {

    Boolean isDualPane;
    GridView gridView;
    ListView listView;
    int position;

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

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.gridview, container, false);

        gridView = (GridView) view.findViewById(R.id.gridViewImage);
        gridView.setAdapter(new MyAdapter(view.getContext()));

        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        View detailFrame = getActivity().findViewById(R.id.detail);

        isDualPane = detailFrame != null && detailFrame.getVisibility() == View.VISIBLE;

        gridView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1, int pos, long arg3) {
                if (!isDualPane) {
                    Intent intent = new Intent();
                    intent.setClass(getActivity(), DetailActivity.class);
                    intent.putExtra("position", pos);
                    startActivity(intent);
                } else {
                    DetailFragment detailFragment = (DetailFragment) getFragmentManager().findFragmentById(R.id.detail);

                    if (detailFragment == null || detailFragment.getIndex() != pos) {

                        detailFragment = new DetailFragment(pos);
                        FragmentTransaction ft = getFragmentManager().beginTransaction();

                        ft.replace(R.id.detail, detailFragment);
                        ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
                        ft.commit();
                    }
                }
            }
        });

        super.onActivityCreated(savedInstanceState);
    }
}

现在这是我的图片适配器 - MyAdapter - 我的图片扩展了BaseAdapter。

public class MyAdapter extends BaseAdapter {

    private Context mContext;

    public MyAdapter(Context c) {
        mContext = c;
    }

    @Override
    public int getCount() {
        return mThumbIds.length;
    }

    @Override
    public Object getItem(int arg0) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView;
        if (convertView == null) { // if it's not recycled, initialize some attributes
            imageView = new ImageView(mContext);
            imageView.setLayoutParams(new GridView.LayoutParams(100, 100));
            imageView.setImageResource(mThumbIds[position]);
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            imageView.setPadding(0, 0, 0, 0);
        } else {
            imageView = (ImageView) convertView;
        }
        imageView.setImageResource(mThumbIds[position]);
        return imageView;
    }

    static Integer[] mThumbIds = { R.drawable.pic1, R.drawable.pic2,
            R.drawable.pic3, R.drawable.pic4, R.drawable.pic5, R.drawable.pic6,
            R.drawable.pic7, R.drawable.pic8, R.drawable.pic9,
            R.drawable.pic10, R.drawable.pic11, R.drawable.pic12,
            R.drawable.pic13,
    };
}

现在我正在共享这些片段的XML文件。

<强> main.xml中

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal">

    <fragment
        android:id="@+id/master"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="org.fragment.MasterGridActivity" />

</LinearLayout>

<强> gridview.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

  <GridView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/gridViewImage"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:numColumns="auto_fit"
    android:columnWidth="90dp"
    android:horizontalSpacing="10dp"
    android:verticalSpacing="10dp"
    android:gravity="center"
    android:stretchMode="columnWidth" />
</LinearLayout>

detail_fragment.xml ：此XML用于显示另一个片段中的详细信息。

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical" >

        <ImageView
            android:id="@+id/imageView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:layout_margin="8dp" />

        <TextView
            android:id="@+id/textView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:padding="8dp" />
    </LinearLayout>
</ScrollView>

<强> detail_act.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

  <ImageView
        android:id="@+id/imageView1"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:src="@drawable/ic_launcher" />
</LinearLayout>

为横向模式和平板电脑制作相同的XML。它对我来说很好。希望它对你有所帮助。

Answer 2

您需要定义event callback to the activity活动回调。也就是说，您的左侧片段必须首先通知容器活动事件发生（即选择了一个列表项）。然后容器活动将此信息传递给正确的片段，然后相应地更新其UI。

我可以更详细地解释一下，但互联网上有几个tutorials就是这样教的。我建议你仔细阅读them中的一些内容，因为一旦你做了这个概念就会更有意义。