Android

RecyclerView与CardView的基础使用

2017-07-11  本文已影响50人  Scorpio_青牙

本文主要介绍RecyclerView和CardView的基础使用,首先说下RecyclerView实现ListView、GridView和瀑布流的功能,其次谈下RecyclerView与CardView的结合使用。

在build.gradle中添加依赖

compile 'com.android.support:recyclerview-v7:25.0.1'
compile 'com.android.support:cardview-v7:25.0.1'

基本使用方法

RecyclerView的xml布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorPrimary">

    <android.support.v7.widget.RecyclerView
         android:id="@+id/swipe_target"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:background="@color/C_E2E4E4"
         android:scrollbars="none"/>

</RelativeLayout>

1.作为ListView使用

//数据源
lists = new ArrayList<String>();
mRecyclerView = (RecyclerView)findViewById(R.id.swipe_target);
//创建默认的线性LayoutManager
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);
//如果可以确定每个item的高度是固定的,设置这个选项可以提高性能
mRecyclerView.setHasFixedSize(true);
//创建并设置Adapter
mAdapter = new ItemAdapter(this, lists);
mRecyclerView.setAdapter(mAdapter);

2.作为GridView使用

//数据源
lists = new ArrayList<String>();
mRecyclerView = (RecyclerView)findViewById(R.id.swipe_target);
//创建默认的GridLayoutManager
mLayoutManager = new GridLayoutManager(this, 2);
mRecyclerView.setLayoutManager(mLayoutManager);
//如果可以确定每个item的高度是固定的,设置这个选项可以提高性能
mRecyclerView.setHasFixedSize(true);
//创建并设置Adapter
mAdapter = new ItemAdapter(this, lists);
mRecyclerView.setAdapter(mAdapter);

RecyclerView作为Listview、GridView使用的Adapter

public class ItemAdapter extends RecyclerView.Adapter<ItemAdapter.ItemViewHolder> implements View.OnClickListener, View.OnLongClickListener {

    private Context mContext;
    private List<String> datas = null;

    public ItemAdapter(Context context, List<String> lists){
        mContext = context;
        this.datas = lists;
    }

    //创建新View,被LayoutManager所调用
    @Override
    public ItemViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(mContext).inflate(R.layout.linearlayout_item, parent, false);

        ItemViewHolder holder = new ItemViewHolder(view);
        //view注册事件
        view.setOnClickListener(this);
//        view.setOnLongClickListener(this);

        return holder;
    }

    //将数据与界面进行绑定的操作
    @Override
    public void onBindViewHolder(ItemViewHolder holder, int position) {
        //将数据保存在itemView的Tag中,以便点击时进行获取
        holder.itemView.setTag(datas.get(position));
        //控制绑定数据
        holder.text.setText(datas.get(position));
    }

    //获取数据的数量
    @Override
    public int getItemCount() {
        return datas.size();
    }

    //自定义的ViewHolder, 持有每个Item的的所有界面元素
    static class ItemViewHolder extends RecyclerView.ViewHolder{

        private TextView text;

        public ItemViewHolder(View view){
            super(view);
            text = (TextView)view.findViewById(R.id.item_tv);
        }
    }

    //定义Item点击事件
    public  interface OnRecyclerViewItemClickListener{
        //点击事件
        void onItemClick(View view, String str);
        //长按事件
        void onItemLongClick(View view, String str);
    }

    private OnRecyclerViewItemClickListener mOnItemClickListener;

    public void setOnItemClickListener(OnRecyclerViewItemClickListener listener) {
        mOnItemClickListener = listener;
    }

    //点击事件
    @Override
    public void onClick(View v) {
        if(mOnItemClickListener != null){
            mOnItemClickListener.onItemClick(v, (String)v.getTag());
        }
    }

    //长按事件
    @Override
    public boolean onLongClick(View v) {
        if(mOnItemClickListener != null){
            mOnItemClickListener.onItemLongClick(v, (String)v.getTag());
        }
        return false;
    }
}

3.作为瀑布流样式使用

//数据源
lists = new ArrayList<String>();
mRecyclerView = (RecyclerView)findViewById(R.id.swipe_target);
//创建默认的StaggeredGridLayoutManager
mLayoutManager = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL);
mRecyclerView.setLayoutManager(mLayoutManager);
//如果可以确定每个item的高度是固定的,设置这个选项可以提高性能
mRecyclerView.setHasFixedSize(true);
//创建并设置Adapter
mAdapter = new StaggeredAdapter(this, lists);
mRecyclerView.setAdapter(mAdapter);

RecyclerView作为瀑布流使用的Adapter

public class StaggeredAdapter extends RecyclerView.Adapter<StaggeredAdapter.StaggeredViewHolder> implements View.OnClickListener, View.OnLongClickListener {

    private Context mContext;
    private List<String> datas = null;

    public StaggeredAdapter(Context context, List<String> lists){
        mContext = context;
        this.datas = lists;
    }

    //创建新View,被LayoutManager所调用
    @Override
    public StaggeredViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(mContext).inflate(R.layout.linearlayout_item, parent, false);

        StaggeredViewHolder holder = new StaggeredViewHolder(view);
        //view注册事件
        view.setOnClickListener(this);
//        view.setOnLongClickListener(this);

        return holder;
    }

    //将数据与界面进行绑定的操作
    @Override
    public void onBindViewHolder(StaggeredViewHolder holder, int position) {
        //将数据保存在itemView的Tag中,以便点击时进行获取
        holder.itemView.setTag(datas.get(position));
        //控制绑定数据
        holder.text.setText(datas.get(position));
        //更改高度,不同位置高度不同
        holder.text.setHeight(200 + (position % 2) * 60);
    }

    //获取数据的数量
    @Override
    public int getItemCount() {
        return datas.size();
    }

    //自定义的ViewHolder, 持有每个Item的的所有界面元素
    static class StaggeredViewHolder extends RecyclerView.ViewHolder{

        private TextView text;

        public StaggeredViewHolder(View view){
            super(view);
            text = (TextView)view.findViewById(R.id.item_tv);
        }
    }

    //定义Item点击事件
    public  interface OnRecyclerViewItemClickListener{
        //点击事件
        void onItemClick(View view, String str);
        //长按事件
        void onItemLongClick(View view, String str);
    }

    private OnRecyclerViewItemClickListener mOnItemClickListener;

    public void setOnItemClickListener(OnRecyclerViewItemClickListener listener) {
        mOnItemClickListener = listener;
    }

    //点击事件
    @Override
    public void onClick(View v) {
        if(mOnItemClickListener != null){
            mOnItemClickListener.onItemClick(v, (String)v.getTag());
        }
    }

    //长按事件
    @Override
    public boolean onLongClick(View v) {
        if(mOnItemClickListener != null){
            mOnItemClickListener.onItemLongClick(v, (String)v.getTag());
        }
        return false;
    }
}

CardView的特点就是可以设置圆角、阴影,而以前我们需要自己定义shape文件来实现,下面我们看下CradView新增的属性:

CardView在RecyclerView的item布局的使用xml如下

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="5dp"
    app:cardCornerRadius="8dp"
    app:cardBackgroundColor="@color/white">

    <TextView
        android:id="@+id/item_tv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="20dp"
        android:gravity="center"
        android:text="item数据0"
        android:textSize="24sp"/>

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

效果图

ZJ8OFAD3@@[B@3309]WYJ%1.png

希望能给您带去帮助、感谢您的阅读。

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