ListView行中的Android库

Question

我正在努力实现Airbnb app for Android的效果，列出每行中水平滚动的图库（每行都有顶层，标题为so）。我在每个单元格中使用ListView FrameLayout和ViewPager，但滚动时我得到NullPointerException。带有图片的Fragments会丢失指向父片段的指针（我发现Android Support Library中有一些错误，我花了几天时间寻找解决方案）。

现在我不想显示代码。我只想知道Viewpager ListView是个好主意，或者我必须以另一种方式来做。也许有一个库可以实现这种行为？

Answer 1

我在此页http://dorkus.hatenablog.com/entry/2014/01/16/021853找到了解决方案。需要一些优化，但是它是未来工作的良好基础。

修改

View in action

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="vertical" >

    <ListView
    android:id="@+id/listView"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
    </ListView>

</LinearLayout>

row.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" >

<android.support.v4.view.ViewPager
    android:id="@+id/viewpager"
    android:layout_width="match_parent"
    android:layout_height="60dp"
    android:layout_gravity="center" />

</LinearLayout>

page1.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:background="#ffffff"
    android:orientation="vertical" >

    <TextView
    android:id="@+id/text"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:textColor="#000000"
    android:singleLine="true"
    android:textSize="20sp" />

</LinearLayout>

page2.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="horizontal" >

    <RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_weight="1"
    android:background="#00000000" >

    </RelativeLayout>

    <Button
    android:id="@+id/button2"
    android:layout_width="70dp"
    android:layout_height="match_parent"
    android:background="#cc2828"
    android:text="削除"
    android:textColor="#ffffff" />

</LinearLayout>

MyListAdapter.java

public class MyListAdapter extends ArrayAdapter<String>{

    private LayoutInflater inflater = null;
    private static final float BUTTON_WIDTH_DP = 70f;
    private int margin;

    public MyListAdapter(Context context, int resource,String[] items) {
        super(context, resource,items);
        inflater = LayoutInflater.from(context);

        //ページ2のRelativeLayoutの幅を計算してmarginへ格納する。
        float density = getContext().getResources().getDisplayMetrics().density; 
        int buttonWidthPX = (int) (BUTTON_WIDTH_DP * density + 0.5f);

        WindowManager wm = (WindowManager)getContext().getSystemService(getContext().WINDOW_SERVICE);
    Display dp = wm.getDefaultDisplay();
        margin = dp.getWidth() - buttonWidthPX;

    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        if(convertView == null){
            convertView = inflater.inflate(R.layout.row,null);
        }

        ViewPager viewPager = (ViewPager)convertView.findViewById(R.id.viewpager);
        viewPager.setPageMargin(-margin);
        MyPagerAdapter adapter = new MyPagerAdapter(getContext(),getItem(position));
        viewPager.setAdapter(adapter);

        return convertView;
    }
}

MyPagerAdapter.java

public class MyPagerAdapter extends PagerAdapter{

    private LayoutInflater inflater;

    private static final int PAGE_NUM = 2;
    private String str;

    public MyPagerAdapter(Context context,String str) {
        super();
        inflater = LayoutInflater.from(context);
        this.str = str;
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {

        LinearLayout layout = null;
        if(position == 0){
            layout = (LinearLayout)inflater.inflate(R.layout.page1, null);
            TextView text = (TextView)layout.findViewById(R.id.text);
            text.setText(str);
        }else{
            layout = (LinearLayout)inflater.inflate(R.layout.page2, null);
        }

        container.addView(layout);

        return layout;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        ((ViewPager) container).removeView((View) object);
    }

    @Override
    public int getCount() {

        return PAGE_NUM;
    }

    @Override
    public boolean isViewFromObject(View view, Object obj) {

        return view.equals(obj);
    }

}

MainActivity.java

public class MainActivity extends Activity {

    private String str[] = {"項目1","項目2","項目3","項目4","項目5","項目6","項目7","項目8","項目9","項目10"};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        ListView listView = (ListView)findViewById(R.id.listView);
        MyListAdapter adapter = new MyListAdapter(this,R.layout.row,str);
        listView.setAdapter(adapter);
    }
}