ICode9

精准搜索请尝试: 精确搜索
首页 > 其他分享> 文章详细

RecyclerView上拉加载更多

2022-09-09 16:30:08  阅读:244  来源: 互联网

标签:itemView int items data 上拉 context RecyclerView public 加载


为什么要写这个呢,因为RecyclerView的上拉加载不像ListView通过添加FooterView那么方便,很多通过addScrollListener的方式实现的太繁琐,需要添加各种标识,需要交互联动。

不想说废话了,最好的不是好的,适合的才是最好的,代码如下:

public abstract class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    private List<Object> items;
    protected Context context;
    private boolean isLoading;//是否正在加载
    private boolean hasLoadMore;//是否有加载更多,判断依据是如果增加的条目小于 aPageCount,那么就没有了
    private int aPageCount = 10;//每一页多少个,默认10,可根据后台返回的实际情况调节
    private onl oadMoreListener loadMoreListener;
    private int currPage = 1;//当前加载的页标
    private final int TYPE_ITEM = 0, TYPE_FOOTER = 1;

    public MyAdapter(List<? extends Object> items, Context context) {
        if (items != null) {
            this.items = new ArrayList<>();
            this.items.addAll(items);
        }
        this.context = context;
    }

    public MyAdapter(List<? extends Object> items, Context context, int aPageCount) {
        if (items != null) {
            this.items = new ArrayList<>();
            this.items.addAll(items);
        }
        this.context = context;
        this.aPageCount = aPageCount;
    }

    public void setLoadMoreListener(OnLoadMoreListener loadMoreListener) {
        this.loadMoreListener = loadMoreListener;
    }

    public void notifyDataSetAndRefresh(List<? extends Object> data) {
        if (items == null) {
            items = new ArrayList<>();
        } else {
            items.clear();
        }
        currPage = 1;
        hasLoadMore = false;
        if (data != null) {
            if (data.size() >= aPageCount) {
                hasLoadMore = true;
            }
            items.addAll(data);
        }
        super.notifyDataSetChanged();
        isLoading = false;
    }


    public void notifyDataSetAndAdd(List<? extends Object> data) {
        if (items == null) items = new ArrayList<>();
        hasLoadMore = false;
        if (data != null) {
            if (data.size() >= aPageCount) {
                hasLoadMore = true;
            }
            items.addAll(data);
            if (loadMoreListener == null) {
                super.notifyItemRangeInserted(items.size() - data.size(), data.size());
            } else {
                super.notifyItemRangeChanged(items.size() - data.size(), data.size() + 1);
            }
            isLoading = false;
        }
    }

    public abstract void onBindItemData(RecyclerView.ViewHolder holder, Object itemBean);

    public abstract RecyclerView.ViewHolder getItemViewHolder(ViewGroup parent, int viewType);

    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        if (viewType == TYPE_FOOTER) {
            return new MyFooterViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.item_loadmore, parent, false));
        }
        return getItemViewHolder(parent, viewType);
    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
        int itemViewType = getItemViewType(position);
        if (itemViewType == TYPE_FOOTER) {
            MyFooterViewHolder footerViewHolder = (MyFooterViewHolder) holder;
            footerViewHolder.refreshFooter(hasLoadMore);
            if (!isLoading && hasLoadMore) {
                isLoading = true;
                loadMoreListener.onLoadMore(++currPage);
            }
        } else {
            onBindItemData(holder, items.get(position));
        }
    }

    @Override
    public int getItemCount() {
        if (items == null) return 0;
        return loadMoreListener == null ? items.size() : items.size() + 1;
    }

    @Override
    public int getItemViewType(int position) {
        if (loadMoreListener != null && position == getItemCount() - 1) return TYPE_FOOTER;
        return TYPE_ITEM;
    }

    class MyFooterViewHolder extends RecyclerView.ViewHolder {
        LinearLayoutCompat llLoading;
        AppCompatTextView tvEnd;

        public MyFooterViewHolder(@NonNull View itemView) {
            super(itemView);
            llLoading = itemView.findViewById(R.id.ll_loading);
            tvEnd = itemView.findViewById(R.id.tv_end);
        }

        public void refreshFooter(boolean hasLoadMore) {
            if (hasLoadMore) {
                if (llLoading.getVisibility() == View.GONE) {
                    llLoading.setVisibility(View.VISIBLE);
                }
                if (tvEnd.getVisibility() == View.VISIBLE) {
                    tvEnd.setVisibility(View.GONE);
                }
            } else {
                if (tvEnd.getVisibility() == View.GONE) {
                    tvEnd.setVisibility(View.VISIBLE);
                }
                if (llLoading.getVisibility() == View.VISIBLE) {
                    llLoading.setVisibility(View.GONE);
                }
            }
        }
    }

    public interface onl oadMoreListener {
        void onl oadMore(int page);
    }
}

item_loadmore.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:padding="5dp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <androidx.appcompat.widget.AppCompatTextView
        android:id="@+id/tv_end"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:text="没有更多了..."
        android:textColor="@android:color/darker_gray" />

    <androidx.appcompat.widget.LinearLayoutCompat
        android:id="@+id/ll_loading"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:orientation="horizontal">

        <ProgressBar
            android:layout_width="30dp"
            android:layout_height="30dp" />

        <androidx.appcompat.widget.AppCompatTextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:text="加载中..."
            android:textColor="@android:color/darker_gray" />
    </androidx.appcompat.widget.LinearLayoutCompat>


</androidx.constraintlayout.widget.ConstraintLayout>

可以看到有两个抽象方法,具体的适配器新建一个类继承他,然后具体的ViewHolder和数据填充在那里面进行,比如:

public class MySearchListAdapter extends MyAdapter {


    public MySearchListAdapter(List<?> items, Context context) {
        super(items, context);
    }

    public MySearchListAdapter(List<?> items, Context context, int aPageCount) {
        super(items, context, aPageCount);
    }

	//带有我自己view的ViewHolder返回回去
    @Override
    public RecyclerView.ViewHolder getItemViewHolder(ViewGroup parent, int viewType) {
        return new MVViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.item_mv, null));
    }

	//具体的自己的数据绑定
    @Override
    public void onBindItemData(RecyclerView.ViewHolder holder, Object movieB) {
        MVViewHolder mvViewHolder = (MVViewHolder) holder;
        MBean mBean = (MBean) movieB;
        mvViewHolder.title.setText(mBean.title);
        mvViewHolder.leader.setText(mBean.leader);
        mvViewHolder.actor.setText(mBean.actor);
        mvViewHolder.country.setText(mBean.country);
        mvViewHolder.desc_simple.setText(mBean.desc_simple);
        Glide.with(context).load(mBean.imgUrl).into(mvViewHolder.iv);
        mvViewHolder.itemData = mBean;
    }

	//MBean是你自己的modal
    class MVViewHolder extends RecyclerView.ViewHolder {
        TextView title, leader, actor, country, desc_simple;
        ImageView iv;
        ConstraintLayout cl;
        MBean itemData;

        public MVViewHolder(@NonNull View itemView) {
            super(itemView);
            title = itemView.findViewById(R.id.title);
            leader = itemView.findViewById(R.id.leader);
            actor = itemView.findViewById(R.id.actor);
            country = itemView.findViewById(R.id.country);
            desc_simple = itemView.findViewById(R.id.desc_simple);
            iv = itemView.findViewById(R.id.iv);
            cl = itemView.findViewById(R.id.cl);
            cl.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                }
            });
        }
    }
}

MyFooterViewHolder是刷新的样式,你也可以自己根据产品需求自定义

标签:itemView,int,items,data,上拉,context,RecyclerView,public,加载
来源: https://www.cnblogs.com/maowuge/p/16673261.html

本站声明: 1. iCode9 技术分享网(下文简称本站)提供的所有内容,仅供技术学习、探讨和分享;
2. 关于本站的所有留言、评论、转载及引用,纯属内容发起人的个人观点,与本站观点和立场无关;
3. 关于本站的所有言论和文字,纯属内容发起人的个人观点,与本站观点和立场无关;
4. 本站文章均是网友提供,不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属;如您发现该文章侵犯了您的权益,可联系我们第一时间进行删除;
5. 本站为非盈利性的个人网站,所有内容不会用来进行牟利,也不会利用任何形式的广告来间接获益,纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。

专注分享技术,共同学习,共同进步。侵权联系[81616952@qq.com]

Copyright (C)ICode9.com, All Rights Reserved.

ICode9版权所有