ScrollView

Question

我在ViewPager内ScrollView遇到了问题。我创建了适配器，当LinearLayout是根布局时，它可以正常工作。但是当我切换到ScrollView时，它并没有显示任何图像。我需要ScrollView，因为我要显示一些元素，并且它必须是可滚动的。我的布局位于activity_exercises_preview.xml文件中。

布局，不起作用：

<ScrollView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="5dp"
    android:background="@color/colorBackground">

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

        <android.support.v7.widget.CardView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:cardCornerRadius="0dp"
            android:id="@+id/cv"
            >

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical"
                android:minHeight="200dp">

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

                </android.support.v4.view.ViewPager>

            </LinearLayout>

        <android.support.v7.widget.CardView...>

        <android.support.v7.widget.CardView...>

        <android.support.v7.widget.CardView...>

    </LinearLayout>

</ScrollView>

布局，有效，但没有ScrollView：

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="5dp"
    android:background="@color/colorBackground">

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

        <android.support.v7.widget.CardView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:cardCornerRadius="0dp"
            android:id="@+id/cv"
            >

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical"
                android:minHeight="200dp">

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

                </android.support.v4.view.ViewPager>

            </LinearLayout>

        <android.support.v7.widget.CardView...>

        <android.support.v7.widget.CardView...>

        <android.support.v7.widget.CardView...>

    </LinearLayout>

</LinearLayout>

我的适配器：

public class CustomAdapter extends PagerAdapter{

    Context context;
    int[] imageId = {R.drawable.icon, R.drawable.gwiazdki, R.drawable.arnoldki_3};

    public CustomAdapter(Context context){
        this.context = context;
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        // TODO Auto-generated method stub

        LayoutInflater inflater = ((Activity)context).getLayoutInflater();

        View viewItem = inflater.inflate(R.layout.image_item, container, false);
        ImageView imageView = (ImageView) viewItem.findViewById(R.id.imageView);
        imageView.setImageResource(imageId[position]);
        ((ViewPager)container).addView(viewItem);

        return viewItem;
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return imageId.length;
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        // TODO Auto-generated method stub

        return view == ((View)object);
    }


    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        // TODO Auto-generated method stub
        ((ViewPager) container).removeView((View) object);
    }
}

    Activity:



public class ExercisesPreview extends AppCompatActivity {
        List<Exercise> exercises;
        Exercise exercise;
        ViewPager viewPager;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_exercises_preview);

            viewPager = (ViewPager) findViewById(R.id.viewPager);
            PagerAdapter adapter = new CustomAdapter(ExercisesPreview.this);
            viewPager.setAdapter(adapter);
            viewPager.setOnTouchListener(new View.OnTouchListener() {
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    viewPager.getParent().requestDisallowInterceptTouchEvent(true);
                    return false;
                }
            });

        }
    (...)
    }

image_item.xml：

<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/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />

</LinearLayout>

有什么想法吗？

Answer 1

在scrollView中使用此自定义ViewPager：

public class WrapContentHeightViewPager extends ViewPager {
public WrapContentHeightViewPager(Context context) {
    super(context);
}

public WrapContentHeightViewPager(Context context, AttributeSet attrs) {
    super(context, attrs);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    int height = 0;
    for (int i = 0; i < getChildCount(); i++) {
        View child = getChildAt(i);
        child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
        int h = child.getMeasuredHeight();
        if (h > height) height = h;
    }
    heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}}