android - 是否可以在 ScrollView 中有一个 ViewPager？

Question

我正在尝试在 ScrollView 中使用 ViewPager，但没有出现 ViewPager。如果我删除 ScrollView，ViewPager 会显示得很好。

我用以下内容创建了一个简单的测试项目:

main.xml 布局:

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

        <android.support.v4.view.ViewPager
            android:layout_width="fill_parent" 
            android:layout_height="fill_parent"
            android:id="@+id/viewpager" />

    </ScrollView>
</LinearLayout>

Activity 类:

public class ScrollViewWithViewPagerActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        ViewPager vp = (ViewPager) findViewById(R.id.viewpager);
        vp.setAdapter(new MyPagerAdapter(this));
    }
}

class MyPagerAdapter extends PagerAdapter {

    private Context ctx;

    public MyPagerAdapter(Context context) {
        ctx = context;
    }

    @Override
    public int getCount() {
        return 2;
    }

    @Override
    public Object instantiateItem(View collection, int position) {

        TextView tv =  new TextView(ctx);
        tv.setTextSize(50);
        tv.setTextColor(Color.WHITE);
        tv.setText("SMILE DUDE, SMILE DUDE, SMILE DUDE, SMILE DUDE, SMILE DUDE, " +
                "SMILE DUDE, SMILE DUDE, SMILE DUDE, SMILE DUDE, SMILE DUDE, " +
                "SMILE DUDE, SMILE DUDE, SMILE DUDE, SMILE DUDE, SMILE DUDE, " +
                "SMILE DUDE, SMILE DUDE, SMILE DUDE");

        ((ViewPager) collection).addView(tv);

        return tv;

    }

    @Override
    public void destroyItem(View collection, int position, Object view) {
         ((ViewPager) collection).removeView((View) view);
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == object;
    }

    @Override
    public Parcelable saveState() {
        return null;
    }

    @Override
    public void restoreState(Parcelable arg0, ClassLoader arg1) {
    }

    @Override
    public void startUpdate(View arg0) {
    }

    @Override
    public void finishUpdate(View arg0) {
    }
}

感谢您的宝贵时间。

Answer 1

我想通了；

我需要将 android:fillViewport="true" 添加到 ScrollView 元素。