java.lang.IllegalStateException: Horizo​​ntalScrollView 只能承载一个直接子级

Question

I want to realize the Gallery using HorizontalScrollView. But it throws java.lang.illegalStateException. The logcat hint that the HorizontalScrollView can host only one direct child. I only set one direct child - LinearLayout to it. I searched from the Internet, but haven't solved the problem. Hope anyone can help me. Belows are the code.

xml

<HorizontalScrollView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="8dp"
    android:scrollbars="none"
    >

    <LinearLayout
       android:id="@+id/gallery_layout"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:orientation="horizontal">
    </LinearLayout>

</HorizontalScrollView>

item xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:paddingTop="10dp"
    android:paddingLeft="8dp"
    android:paddingRight="8dp"
    android:paddingBottom="20dp"
    >

    <ImageView
        android:id="@+id/trend_item_imageview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingBottom="8dp"
        android:src="@drawable/gallery0"
        />

    <TextView
        android:id="@+id/trend_item_textview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="权利的游戏"
        android:textSize="16sp"
        />

</LinearLayout>

Fragment

public class DiscoverFragment extends Fragment {

    private int[] imageResources = {R.drawable.gallery0, R.drawable.gallery1, R.drawable.gallery2,
        R.drawable.gallery3, R.drawable.gallery4, R.drawable.gallery5};

    private String[] imageDescriptions = {"权利的游戏", "风吹的风景", "插画背景", "美食君", "吃", "你好四月"};

    private List<TrendItem> trendItemList;
    private LinearLayout galleryLayout;

    public DiscoverFragment() {
    // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_discover, container, false);
        ButterKnife.bind(this, view);
        galleryLayout = ButterKnife.findById(view, R.id.gallery_layout);
        initData();
        setView();
        return view;
    }

    private void initData(){
        trendItemList = new ArrayList<>();
        for (int i = 0; i < imageResources.length; i++){
            TrendItem trendItem = new TrendItem();
            trendItem.setImageResource(imageResources[i]);
            trendItem.setText(imageDescriptions[i]);
            trendItemList.add(trendItem);
        }
    }

    private void setView(){
        for (int i = 0; i < trendItemList.size(); i++){
            LayoutInflater inflater = LayoutInflater.from(getContext());
            View view = inflater.inflate(R.layout.trend_item, galleryLayout, false);
            ImageView trendItemImageView = ButterKnife.findById(view, R.id.trend_item_imageview);
            TextView trendItemTextView = ButterKnife.findById(view, R.id.trend_item_textview);
            trendItemImageView.setImageResource(trendItemList.get(i).getImageResource());
            trendItemTextView.setText(trendItemList.get(i).getText());
            galleryLayout.addView(view);
        }
    }
}

Answer 1

Meaning, you have to add the ImageView , TextView to the Linearlayout . when you add the imageview you are adding it to the HorizontalScrollview which also has a LinearLayout in it their by adding 2 child elements to the HorizontalScrollView which you cannot do.

<HorizontalScrollView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="8dp"
android:scrollbars="none">

<LinearLayout
   android:id="@+id/gallery_layout"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:orientation="horizontal">

<ImageView
    android:id="@+id/trend_item_imageview"
    android:layout_width="your_size"
    android:layout_height="your_size"
    android:src="@drawable/gallery0"/>

<TextView
    android:id="@+id/trend_item_textview"
    android:layout_width="your_size"
    android:layout_height="your_size"
    android:text="权利的游戏"
    android:textSize="16sp"/>

</LinearLayout>

</HorizontalScrollView>