android - ListView 或 2 个 ListView 中的 GridView 更好？

Question

我试图在我的 Activity 中使用带有 ListView 的 GridView ，但出现错误。

还有其他方法可以得到下面的结果吗？

在我的主要 Activity 中，我想要一个 ListView 显示大 ImageView ，第二个将它们显示为每行 2 个图像，我应该使用 GridView 还是第二个 ListView 就足够了？

这是我的代码

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:fillViewport="true" >

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

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
          android:text="sssss"
            android:textSize="16sp"
            android:padding="10dp"
            android:background="#ffe474" />

        <ListView
            android:id="@+id/list3"
            android:layout_width="wrap_content"
            android:layout_height="1500dp"
            android:background="#eeeeee" >
        </ListView>

         <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center_vertical"
            android:text="Recommanded"
            android:textSize="18sp"
            android:padding="10dp"
            android:background="#ffe474" />


        <ListView
            android:id="@+id/list1"
            android:layout_width="wrap_content"
            android:layout_height="1500dp"
            android:background="#eeeeee" >
        </ListView>

    </LinearLayout>


</ScrollView>

Answer 1

更合适和直接的解决方案是将 RecyclerView 与 GridLayoutManager 一起使用。 GridLayoutManager 采用 SpanSizeLookup 对象，它允许您指定每个项目将占用多少跨度。

此问题的完整解决方案包括以下部分:

带有 RecyclerView、GridLayoutManager 和自定义 SpanSizeLookup 的 Activity

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        // specify that grid will consist of 2 columns
        GridLayoutManager gridLayoutManager = new GridLayoutManager(getApplicationContext(), 2);
        // provide our CustomSpanSizeLookup which determines how many spans each item in grid will occupy
        gridLayoutManager.setSpanSizeLookup(new CustomSpanSizeLookup());
        // provide our GridLayoutManager to the view
        recyclerView.setLayoutManager(gridLayoutManager);
        // this is fake list of images
        List<Integer> imageResList = getMockedImageList();
        // finally, provide adapter to the recycler view
        Adapter adapter = new Adapter(imageResList);
        recyclerView.setAdapter(adapter);
    }


    private List<Integer> getMockedImageList() {
        // fake images list, you'd need to upload your own image resources
        List<Integer> imageResList = new ArrayList<Integer>();

        imageResList.add(R.drawable.img1);
        imageResList.add(R.drawable.img2);
        imageResList.add(R.drawable.img3);
        imageResList.add(R.drawable.img4);
        imageResList.add(R.drawable.img5);
        imageResList.add(R.drawable.img6);

        return imageResList;
    }


    private static class CustomSpanSizeLookup extends GridLayoutManager.SpanSizeLookup {
        @Override
        public int getSpanSize(int i) {
            if(i == 0 || i == 1) {
                // grid items on positions 0 and 1 will occupy 2 spans of the grid
                return 2;
            } else {
                // the rest of the items will behave normally and occupy only 1 span
                return 1;
            }
        }
    }
}

RecyclerView 适配器

public class Adapter extends RecyclerView.Adapter {
    // I assume that you will pass images as list of resources, but this can be easily switched to a list of URLS
    private List<Integer> imageResList = new ArrayList<Integer>();

    public Adapter(List<Integer> imageUrlList) {
        this.imageResList = imageUrlList;
    }


    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View itemView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.recycle_view_item, viewGroup, false);

        return new ItemViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int i) {
        ItemViewHolder itemViewHolder = (ItemViewHolder) viewHolder;
        itemViewHolder.item.setImageResource(imageResList.get(i));
    }

    @Override
    public int getItemCount() {
        return imageResList.size();
    }


    private static class ItemViewHolder extends RecyclerView.ViewHolder {
        private ImageView item;

        public ItemViewHolder(View itemView) {
            super(itemView);

            this.item = (ImageView) itemView.findViewById(R.id.item_image);
        }
    }
}

activity_main.xml布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</RelativeLayout>

recycler_view_item.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="match_parent"
    android:layout_height="150dp"
    android:padding="10dp">

    <ImageView
        android:id="@+id/item_image"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scaleType="centerCrop"/>

</LinearLayout>

最后一部分是确保在 RecyclerView 的 build.gradle 文件中添加依赖项:

dependencies {
    compile 'com.android.support:recyclerview-v7:21.0.+'
}

结果如下:

这个解决方案的优点是:

1. 它具有可扩展性、轻量级并且高度可定制
2. 它很高效，因为它会在您上下滚动时回收 View
3. 它不需要处理触摸事件，一旦您添加任何额外的触摸功能，触摸事件就很容易变得很难处理

希望对您有所帮助。