RecyclerView的三种布局排列方式以及两种点击事件的实现

1. RecyclerView的三种内置布局排列方式LinearLayoutManager，GridLayoutManager，以及StaggeredGridLayoutManager。

1) LinearLayoutManager

• LinearLayoutManager实现纵向排列

LinearLayoutManager layoutManager = new LinearLayoutManager(this);
layoutManager.setOrientation(LinearLayoutManager.VERTICAL); //可以不写，因为LinearLayoutManager默认的就是纵向排列方式
recyclerView.setLayoutManager(layoutManager);

• LinearLayoutManager实现横向排列

        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
        recyclerView.setLayoutManager(layoutManager);

2) GridLayoutManager 网格式排列

        GridLayoutManager layoutManager = new GridLayoutManager(this,2);
        recyclerView.setLayoutManager(layoutManager);

其中new GridLayoutManager();有两个参数，上下文和列数

3） StaggeredGridLayoutManager 瀑布流布局

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

2.RecyclerView的两种点击事件

• 在RecyclerVIew的适配器中的onCreateViewHolder()方法里

    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.gril_item, parent, false);
        final ViewHolder holder = new ViewHolder(view);
        holder.gril_image.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int position = holder.getAdapterPosition();
                Intent intent = new Intent(context,SecondActivity.class);
                context.startActivity(intent);
            }
        });
        return holder;
    }

• 通过接口回调

public class recyclerViewClickAdapter extends RecyclerView.Adapter<recyclerViewClickAdapter.ViewHolder> implements View.OnClickListener, View.OnLongClickListener {

    private Context context;
    private List<StoryBean> mList;

    //接口回调步骤二：定义成员变量
    private MyOnClickListener myOnClickListener;
    private MyOnLongClickListener myOnLongClickListener;


    public recyclerViewClick(Context context, List<StoryBean> mList) {
        this.context = context;
        this.mList = mList;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.item_daily, parent, false);
        ViewHolder holder = new ViewHolder(view);
        view.setOnClickListener(this);
        view.setOnLongClickListener(this);
        return holder;
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        //设置数据
        holder.imageView.setImageResource(mList.get(position).getImage());
        holder.textView.setText(mList.get(position).getTitle());
        //将数据保存在itemView的id中，以便编辑时进行获取
        holder.itemView.setId(position);
    }

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

    class ViewHolder extends RecyclerView.ViewHolder {
        TextView textView;
        ImageView imageView;
        public ViewHolder(View itemView) {
            super(itemView);
            textView = itemView.findViewById(R.id.textview);
            imageView = itemView.findViewById(R.id.imageview);
        }
    }

    //接口回调步骤一：定义监听接口类
    public static interface MyOnClickListener{
        public void OnItemClickListener(View view, int position);
    }

    public static interface MyOnLongClickListener{
        public void OnItemLongClickListener(View view, int position);
    }

    //接口回调步骤三：实例化 暴露给外面的调用者， 定义Listener方法
    public void setOnClickListener(MyOnClickListener listener){
        this.myOnClickListener = listener;
    }

    public void setOnLongClickListener(MyOnLongClickListener listener){
        this.myOnLongClickListener = listener;
    }

    //接口回调步骤四：实现接口回调方法，将点击事件转移给外面的调用者
    @Override
    public void onClick(View v) {
        if (myOnClickListener != null){
            myOnClickListener.OnItemClickListener(v,v.getId());
        }
    }

    @Override
    public boolean onLongClick(View v) {
        if (myOnLongClickListener != null){
            myOnLongClickListener.OnItemLongClickListener(v, v.getId());
        }
        return true;
    }
}

在activit.java中实现RecyclerView的监听

    //添加监听
    adapter.setOnClickListener(new recyclerViewClickAdapter.MyOnClickListener() {
        @Override
        public void OnItemClickListener(View view, int position) {

        }
    });
        adapter.setOnLongClickListener(new recyclerViewClickAdapter.MyOnLongClickListener() {
        @Override
        public void OnItemLongClickListener(View view, int position) {

        }

    });