RecycleView实现查看全部，折叠效果

首先先看图示效果

这个是收起的一个效果

 

这是展示全部的一个效果

代码实现

第一步

题目已经指出，咱用的是recycle  所以就要创建一个recycleview

recyc.xml

<android.support.v7.widget.RecyclerView
    android:id="@+id/recycle"
    android:background="@color/white"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />

有了recycleview之后，咱得自定义一个item

pay_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:gravity="center_horizontal"
    android:orientation="vertical"

    >
    <com.yichen.xuezhifan.util.XCRoundImageView
        android:id="@+id/concern_img"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_margin="10dp"
        android:scaleType="fitCenter"
        app:type="circle"
        android:src="@mipmap/xiaofan_headline"
        />

    <TextView
        android:id="@+id/tea_name"
        android:textColor="@color/black"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="" />
    <!--<TextView-->
        <!--android:layout_width="wrap_content"-->
        <!--android:layout_height="wrap_content"-->
        <!--android:textSize="10dp"-->
        <!--android:padding="5dp"-->
        <!--android:text="数学老师"-->
        <!--/>-->
</LinearLayout>

我一般把这种列表开发称为‘三件套’开发：recycleview（listview）、item、适配器

接下来就是适配器，注意前方高能     因为本人手懒所以一些view都没换， 如果有幸被看到这篇文章而有些地方有些晦涩难懂的话，可以留言评论

public class PayMyTeaAdapter2 extends RecyclerView.Adapter<PayMyTeaAdapter2.MyViewHolder> {
    
    private Context context;
    private List<MyTeacherModel> list;
    
    //判断是footview还是正常的item
    private static final int NORMAL_VIEW = 0;
    private static final int FOOT_VIEW = 1;
    //这个是作为以后扩展留的
    private int view = 0;
    //判断是否显示全部
    private int status = 0;

    public int getStatus() {
        return status;
    }

    public void setStatus(int status) {
        this.status = status;
    }

    public void setNewDate(List<MyTeacherModel> list) {
        //为了延续开发
        this.list = list == null ? new ArrayList<MyTeacherModel>() : list;
        notifyDataSetChanged();
    }

    private OnItemClickListener onItemClickListener = null;


    public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
        this.onItemClickListener = onItemClickListener;
    }

    public PayMyTeaAdapter2(Context context, List<MyTeacherModel> list) {
        this.context = context;
        this.list = list;
    }


    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        View itemView = LayoutInflater.from(context).inflate(R.layout.my_pay_user, viewGroup, false);
        return new MyViewHolder(itemView, i);

    }

    @Override
    public void onBindViewHolder(@NonNull MyViewHolder myViewHolder, int i) {

        if (getItemViewType(i) == NORMAL_VIEW) {
            initView(myViewHolder, i);
            myViewHolder.itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (onItemClickListener != null) {
                        onItemClickListener.onItemClick(v, i, view);
                    }
                }
            });
        } else {
            if (status == 0) {
                changeStaus(myViewHolder);
            } else {
                resumeStatus(myViewHolder);
            }

        }

    }

    public void changeStaus(MyViewHolder myViewHolder) {
        myViewHolder.textView.setText("查看全部");
        GlideApp.with(context).load(R.mipmap.open).into(myViewHolder.imageView);
        myViewHolder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (onItemClickListener != null) {
                    onItemClickListener.onItemClickAll();
                }
            }
        });
    }

    public void resumeStatus(MyViewHolder myViewHolder) {
        myViewHolder.textView.setText("收起");
        GlideApp.with(context).load(R.mipmap.pack).into(myViewHolder.imageView);
        myViewHolder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (onItemClickListener != null) {
                    onItemClickListener.onItemPick();
                }
            }
        });

    }

    public void initView(MyViewHolder myViewHolder, int i) {
        if (list.get(i) != null) {
            if (list.get(i).getYc_avatar() != null) {
                GlideApp.with(context).load(list.get(i).getYc_avatar()).into(myViewHolder.imageView);
            } else {
                GlideApp.with(context).load(R.mipmap.xiaofan_headline).into(myViewHolder.imageView);
            }
            if (list.get(i).getYc_video_name().equals("2")) {
                myViewHolder.textView.setText(list.get(i).getYc_nickname());
            } else {
                myViewHolder.textView.setText(list.get(i).getYc_username());

            }

        }


    }

    @Override
    public int getItemViewType(int position) {
        if (position == getItemCount() - 1 && list.size() > 7) {
            return FOOT_VIEW;
        }
        return NORMAL_VIEW;
    }

    //返回item数量
    @Override
    public int getItemCount() {
        if (status == 0) {
            if (list.size() > 7) {
                return 7;
            } else {
                return list.size();
            }
        } else {
            return list.size() + 1;
        }

    }

    class MyViewHolder extends RecyclerView.ViewHolder {
        ImageView imageView;
        TextView textView;

        public MyViewHolder(@NonNull View itemView, int v) {
            super(itemView);
            textView = itemView.findViewById(R.id.tea_name);
            imageView = itemView.findViewById(R.id.concern_img);

        }
    }

    //回调接口
    public interface OnItemClickListener {
        void onItemClick(View v, int position, int view);

        void onItemClickAll();

        void onItemPick();

    }
}

好了以上就是三件套的内容至于在activity中怎么实现，我只给关键代码咯因为接下来巨简单

 recyclerView2.setAdapter(adapter3);
        adapter3.setOnItemClickListener(new PayMyTeaAdapter2.OnItemClickListener() {
            @Override
            public void onItemClick(View v, int position, int view) {

               

            }

            @Override
            public void onItemClickAll() {
                //这是展示回调
                adapter3.setStatus(1);
                adapter3.setNewDate(myTeacherModel);

            }

            @Override
            public void onItemPick() {
                //这是收起回调
                adapter3.setStatus(0);
                adapter3.setNewDate(myTeacherModel);
            }
        });

以上就是文章开头效果图的代码实现~