android - Android Docs 中没有关于 RecyclerView 和 StaggeredGridLayoutManager 的好例子

Question

我找不到更好的例子来使用 RecyclerView 和 StaggeredGridLayoutManager。甚至在 Android Docs .

Q1. I need some examples which can give proper explanation about how to use RecyclerView with StaggeredGridLayoutManager.

Q2. Can anyone tell me if it is possible to create following layout using RecyclerView with StaggeredGridLayoutManager

到目前为止，我已经找到了 link一点用处都没有。

我也发现了这个 link对于cardlib，但它的实现过于复杂，并且依赖关系过多，这会不必要地增加我的应用程序大小。

Answer 1

对于那些仍在回答这个问题的人。

您可以根据需要修改以下代码:
首先为Android RecyclerView和CardView添加依赖库

compile 'com.android.support:appcompat-v7:23.4.0'
compile 'com.android.support:cardview-v7:23.4.0'
compile 'com.android.support:recyclerview-v7:23.4.0'

您的主要 Activity 布局 activity_main.xml 就像

<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:padding="7dp"
    tools:context=".MainActivity">

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

</RelativeLayout>

在名为 book_list_item.xml

的布局文件中定义卡片的布局

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
card_view:cardUseCompatPadding="true">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/white"
    android:orientation="vertical">

    <TextView
        android:id="@+id/BookName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:textColor="@android:color/black"
        android:textSize="16sp" />

    <TextView
        android:id="@+id/AuthorName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_below="@+id/country_photo"
        android:background="#1976D2"
        android:gravity="center_horizontal"
        android:paddingBottom="8dp"
        android:paddingTop="8dp"
        android:text="@string/hello_world"
        android:textColor="#ffffff"
        android:textSize="13sp" />
</LinearLayout>

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

将此布局定义为一个类 ItemObject.java

public class ItemObject
{
    private String _name;
    private String _author;

    public ItemObject(String name, String auth)
    {
        this._name = name;
        this._author = auth;
    }

    public String getName()
    {
        return _name;
    }

    public void setName(String name)
    {
        this._name = name;
    }

    public String getAuthor()
    {
        return _author;
    }

    public void setAuthor(String auth)
    {
        this._author = auth;
    }
}

定义一个自定义适配器SampleRecyclerViewAdapter来填充卡片

public class SampleRecyclerViewAdapter extends RecyclerView.Adapter<SampleViewHolders>
{
    private List<ItemObject> itemList;
    private Context context;

    public SampleRecyclerViewAdapter(Context context,
        List<ItemObject> itemList)
    {
        this.itemList = itemList;
        this.context = context;
    }

    @Override
    public SampleViewHolders onCreateViewHolder(ViewGroup parent, int viewType)
    {
        View layoutView = LayoutInflater.from(parent.getContext()).inflate(
            R.layout.book_list_item, null);
        SampleViewHolders rcv = new SampleViewHolders(layoutView);
        return rcv;
    }

    @Override
    public void onBindViewHolder(SampleViewHolders holder, int position)
    {
        holder.bookName.setText(itemList.get(position).getName());
        holder.authorName.setText(itemList.get(position).getAuthor());
    }

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

我们还需要为每个ItemObject 设置一个viewholder。所以定义一个类 SampleViewHolders

public class SampleViewHolders extends RecyclerView.ViewHolder implements
    View.OnClickListener
{
    public TextView bookName;
    public TextView authorName;

    public SampleViewHolders(View itemView)
    {
        super(itemView);
        itemView.setOnClickListener(this);
        bookName = (TextView) itemView.findViewById(R.id.BookName);
        authorName = (TextView) itemView.findViewById(R.id.AuthorName);
    }

    @Override
    public void onClick(View view)
    {
        Toast.makeText(view.getContext(),
            "Clicked Position = " + getPosition(), Toast.LENGTH_SHORT)
            .show();
    }
}

现在在 MainActivity 中，将 StaggeredGridLayoutManager 的实例分配给 recycler_view 以定义组件的显示方式。
同时使用 的实例填充卡片SampleRecyclerViewAdapter，如下

public class MainActivity extends AppCompatActivity
{
    private StaggeredGridLayoutManager _sGridLayoutManager;

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

        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        recyclerView.setHasFixedSize(true);

        _sGridLayoutManager = new StaggeredGridLayoutManager(2,
            StaggeredGridLayoutManager.VERTICAL);
        recyclerView.setLayoutManager(_sGridLayoutManager);

        List<ItemObject> sList = getListItemData();

        SampleRecyclerViewAdapter rcAdapter = new SampleRecyclerViewAdapter(
            MainActivity.this, sList);
        recyclerView.setAdapter(rcAdapter);
    }

    private List<ItemObject> getListItemData()
    {
        List<ItemObject> listViewItems = new ArrayList<ItemObject>();
        listViewItems.add(new ItemObject("1984", "George Orwell"));
        listViewItems.add(new ItemObject("Pride and Prejudice", "Jane Austen"));
        listViewItems.add(new ItemObject("One Hundred Years of Solitude", "Gabriel Garcia Marquez"));
        listViewItems.add(new ItemObject("The Book Thief", "Markus Zusak"));
        listViewItems.add(new ItemObject("The Hunger Games", "Suzanne Collins"));
        listViewItems.add(new ItemObject("The Hitchhiker's Guide to the Galaxy", "Douglas Adams"));
        listViewItems.add(new ItemObject("The Theory Of Everything", "Dr Stephen Hawking"));

        return listViewItems;
    }
}

输出看起来像这样

根据您的要求，您可以在 book_list_item.xml 中合并一个 ImageView 并在 SampleViewHolders 中相应地填充它
另请注意，要将列数从 2 更改为 3。

您可以将 MainActivity 中的声明更改为

_sGridLayoutManager = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL);
recyclerView.setLayoutManager(_sGridLayoutManager);

这将给出这样的输出

这里是 another simple tutorial