RecyclerView的adapter添加头部和尾部

header和footer包装器类

import android.support.v4.util.SparseArrayCompat;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.view.View;
import android.view.ViewGroup;

/**
 * 介绍:一个给RecyclerView添加HeaderView FooterView的装饰Adapter类
 * 重点哦~ RecyclerView的HeaderView将可以被系统回收,不像老版的HeaderView是一个强引用在内存里
 * 作者:zhangxutong
 * 邮箱:zhangxutong@imcoming.com
 * 时间: 2016/8/2.
 */
public abstract class HeaderRecyclerAndFooterWrapperAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    private static final int BASE_ITEM_TYPE_HEADER = 1000000;//headerview的viewtype基准值
    private static final int BASE_ITEM_TYPE_FOOTER = 2000000;//footerView的ViewType基准值

    //存放HeaderViews的layoudID和data,key是viewType,value 是 layoudID和data,
    // 在createViewHOlder里根据layoutId创建UI,
    // 在onbindViewHOlder里依据这个data渲染UI,同时也将layoutId回传出去用于判断何种Header
    private SparseArrayCompat<SparseArrayCompat> mHeaderDatas = new SparseArrayCompat<SparseArrayCompat>();
    private SparseArrayCompat<View> mFooterViews = new SparseArrayCompat<>();//存放FooterViews,key是viewType

    protected RecyclerView.Adapter mInnerAdapter;//内部的的普通Adapter

    public HeaderRecyclerAndFooterWrapperAdapter(RecyclerView.Adapter mInnerAdapter) {
        this.mInnerAdapter = mInnerAdapter;
    }

    public int getHeaderViewCount() {
        return mHeaderDatas.size();
    }

    public int getFooterViewCount() {
        return mFooterViews.size();
    }

    private int getInnerItemCount() {
        return mInnerAdapter != null ? mInnerAdapter.getItemCount() : 0;
    }

    /**
     * 传入position 判断是否是headerview
     *
     * @param position
     * @return
     */
    public boolean isHeaderViewPos(int position) {// 举例, 2 个头,pos 0 1,true, 2+ false
        return getHeaderViewCount() > position;
    }

    /**
     * 传入postion判断是否是footerview
     *
     * @param position
     * @return
     */
    public boolean isFooterViewPos(int position) {//举例, 2个头,2个inner,pos 0 1 2 3 ,false,4+true
        return position >= getHeaderViewCount() + getInnerItemCount();
    }

    /**
     * 添加HeaderView
     *
     * @param layoutId headerView 的LayoutId
     * @param data     headerView 的data(可能多种不同类型的header 只能用Object了)
     */
    public void addHeaderView(int layoutId, Object data) {
        //mHeaderViews.put(mHeaderViews.size() + BASE_ITEM_TYPE_HEADER, v);
        SparseArrayCompat headerContainer = new SparseArrayCompat();
        headerContainer.put(layoutId, data);
        mHeaderDatas.put(mHeaderDatas.size() + BASE_ITEM_TYPE_HEADER, headerContainer);
    }

    /**
     * 设置(更新)某个layoutId的HeaderView的数据
     *
     * @param layoutId
     * @param data
     */
    public void setHeaderView(int layoutId, Object data) {
        boolean isFinded = false;
        for (int i = 0; i < mHeaderDatas.size(); i++) {
            SparseArrayCompat sparse = mHeaderDatas.valueAt(i);
            if (layoutId == sparse.keyAt(0)) {
                sparse.setValueAt(0, data);
                isFinded = true;
            }
        }
        if (!isFinded) {//没发现 说明是addHeaderView
            addHeaderView(layoutId, data);
        }
    }


    /**
     * 设置某个位置的HeaderView
     *
     * @param headerPos 从0开始,如果pos过大 就是addHeaderview
     * @param layoutId
     * @param data
     */
    public void setHeaderView(int headerPos, int layoutId, Object data) {
        if (mHeaderDatas.size() > headerPos) {
            SparseArrayCompat headerContainer = new SparseArrayCompat();
            headerContainer.put(layoutId, data);
            mHeaderDatas.setValueAt(headerPos, headerContainer);
        } else if (mHeaderDatas.size() == headerPos) {//调用addHeaderView
            addHeaderView(layoutId, data);
        } else {
            //
            addHeaderView(layoutId, data);
        }
    }

    /**
     * 添加FooterView
     *
     * @param v
     */
    public void addFooterView(View v) {
        mFooterViews.put(mFooterViews.size() + BASE_ITEM_TYPE_FOOTER, v);
    }

    /**
     * 清空HeaderView数据
     */
    public void clearHeaderView() {
        mHeaderDatas.clear();
    }

    public void clearFooterView() {
        mFooterViews.clear();
    }


    public void setFooterView(View v) {
        clearFooterView();
        addFooterView(v);
    }

    @Override
    public int getItemViewType(int position) {
        if (isHeaderViewPos(position)) {
            return mHeaderDatas.keyAt(position);
        } else if (isFooterViewPos(position)) {//举例:header 2, innter 2, 0123都不是,4才是,4-2-2 = 0,ok。
            return mFooterViews.keyAt(position - getHeaderViewCount() - getInnerItemCount());
        }
        return super.getItemViewType(position - getHeaderViewCount());
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        if (mHeaderDatas.get(viewType) != null) {//不为空,说明是headerview
            //return new ViewHolder(parent.getContext(), mHeaderViews.get(viewType));
            //return createHeader(parent, mHeaderViews.indexOfKey(viewType)); 第一种方法是让子类实现这个方法 构建ViewHolder
            return ViewHolder.get(parent.getContext(), null, parent, mHeaderDatas.get(viewType).keyAt(0), -1);
        } else if (mFooterViews.get(viewType) != null) {//不为空,说明是footerview
            return new ViewHolder(parent.getContext(), mFooterViews.get(viewType));
        }
        return mInnerAdapter.onCreateViewHolder(parent, viewType);
    }

    //protected abstract RecyclerView.ViewHolder createHeader(ViewGroup parent, int headerPos);

    protected abstract void onBindHeaderHolder(ViewHolder holder, int headerPos, int layoutId, Object o);//多回传一个layoutId出去,用于判断是第几个headerview

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        if (isHeaderViewPos(position)) {
            int layoutId = mHeaderDatas.get(getItemViewType(position)).keyAt(0);
            onBindHeaderHolder((ViewHolder) holder, position, layoutId, mHeaderDatas.get(getItemViewType(position)).get(layoutId));
            return;
        } else if (isFooterViewPos(position)) {
            return;
        }
        //举例子,2个header,0 1是头,2是开始,2-2 = 0
        mInnerAdapter.onBindViewHolder(holder, position - getHeaderViewCount());
    }


    @Override
    public int getItemCount() {
        return getInnerItemCount() + getHeaderViewCount() + getFooterViewCount();
    }

    @Override
    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
        mInnerAdapter.onAttachedToRecyclerView(recyclerView);
        //为了兼容GridLayout
        RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
        if (layoutManager instanceof GridLayoutManager) {
            final GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;
            final GridLayoutManager.SpanSizeLookup spanSizeLookup = gridLayoutManager.getSpanSizeLookup();

            gridLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
                @Override
                public int getSpanSize(int position) {
                    int viewType = getItemViewType(position);
                    if (mHeaderDatas.get(viewType) != null) {
                        return gridLayoutManager.getSpanCount();
                    } else if (mFooterViews.get(viewType) != null) {
                        return gridLayoutManager.getSpanCount();
                    }
                    if (spanSizeLookup != null)
                        return spanSizeLookup.getSpanSize(position);
                    return 1;
                }
            });
            gridLayoutManager.setSpanCount(gridLayoutManager.getSpanCount());
        }

    }

    @Override
    public void onViewAttachedToWindow(RecyclerView.ViewHolder holder) {
        mInnerAdapter.onViewAttachedToWindow(holder);
        int position = holder.getLayoutPosition();
        if (isHeaderViewPos(position) || isFooterViewPos(position)) {
            ViewGroup.LayoutParams lp = holder.itemView.getLayoutParams();

            if (lp != null
                    && lp instanceof StaggeredGridLayoutManager.LayoutParams) {

                StaggeredGridLayoutManager.LayoutParams p =
                        (StaggeredGridLayoutManager.LayoutParams) lp;

                p.setFullSpan(true);
            }
        }
    }
}

通用ViewHolder

package mcxtzhang.itemdecorationdemo.utils;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.support.v7.widget.RecyclerView;
import android.text.util.Linkify;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AlphaAnimation;
import android.widget.AbsListView;
import android.widget.Checkable;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.RatingBar;
import android.widget.TextView;

/**
 * 通用的RecyclerView 的ViewHolder ,使用者无需关心
 * Created by zhangxutong .
 * Date: 16/03/11
 */
public class ViewHolder extends RecyclerView.ViewHolder {
    private SparseArray<View> mViews;
    private int mPosition;
    private View mConvertView;
    private Context mContext;
    private int mLayoutId;

    public ViewHolder(Context context, View itemView, ViewGroup parent, int position) {
        super(itemView);
        mContext = context;
        mConvertView = itemView;
        mPosition = position;
        mViews = new SparseArray<View>();
        mConvertView.setTag(this);

    }

    public ViewHolder(Context context, View itemView) {
        super(itemView);
        mContext = context;
        mConvertView = itemView;
        mViews = new SparseArray<View>();
    }


    public static ViewHolder get(Context context, View convertView,
                                 ViewGroup parent, int layoutId, int position) {
        if (convertView == null) {
            View itemView = LayoutInflater.from(context).inflate(layoutId, parent,
                    false);
            ViewHolder holder = new ViewHolder(context, itemView, parent, position);
            holder.mLayoutId = layoutId;
            return holder;
        } else {
            ViewHolder holder = (ViewHolder) convertView.getTag();
            holder.mPosition = position;
            return holder;
        }
    }


    /**
     * 通过viewId获取控件
     *
     * @param viewId
     * @return
     */
    public <T extends View> T getView(int viewId) {
        View view = mViews.get(viewId);
        if (view == null) {
            view = mConvertView.findViewById(viewId);
            mViews.put(viewId, view);
        }
        return (T) view;
    }

    public View getConvertView() {
        return mConvertView;
    }


    /**
     * 设置TextView的值
     *
     * @param viewId
     * @param text
     * @return
     */
    public ViewHolder setText(int viewId, String text) {
        TextView tv = getView(viewId);
        tv.setText(text);
        return this;
    }

    public ViewHolder setSelected(int viewId, boolean selected) {
        View v = getView(viewId);
        v.setSelected(selected);
        return this;
    }

    public ViewHolder setImageResource(int viewId, int resId) {
        ImageView view = getView(viewId);
        view.setImageResource(resId);
        return this;
    }

    public ViewHolder setImageBitmap(int viewId, Bitmap bitmap) {
        ImageView view = getView(viewId);
        view.setImageBitmap(bitmap);
        return this;
    }

    public ViewHolder setImageDrawable(int viewId, Drawable drawable) {
        ImageView view = getView(viewId);
        view.setImageDrawable(drawable);
        return this;
    }

    public ViewHolder setBackgroundColor(int viewId, int color) {
        View view = getView(viewId);
        view.setBackgroundColor(color);
        return this;
    }

    public ViewHolder setBackgroundRes(int viewId, int backgroundRes) {
        View view = getView(viewId);
        view.setBackgroundResource(backgroundRes);
        return this;
    }

    public ViewHolder setTextColor(int viewId, int textColor) {
        TextView view = getView(viewId);
        view.setTextColor(textColor);
        return this;
    }

    public ViewHolder setTextColorRes(int viewId, int textColorRes) {
        TextView view = getView(viewId);
        view.setTextColor(mContext.getResources().getColor(textColorRes));
        return this;
    }

    @SuppressLint("NewApi")
    public ViewHolder setAlpha(int viewId, float value) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            getView(viewId).setAlpha(value);
        } else {
            // Pre-honeycomb hack to set Alpha value
            AlphaAnimation alpha = new AlphaAnimation(value, value);
            alpha.setDuration(0);
            alpha.setFillAfter(true);
            getView(viewId).startAnimation(alpha);
        }
        return this;
    }

    public ViewHolder setVisible(int viewId, boolean visible) {
        View view = getView(viewId);
        view.setVisibility(visible ? View.VISIBLE : View.GONE);
        return this;
    }

    public ViewHolder linkify(int viewId) {
        TextView view = getView(viewId);
        Linkify.addLinks(view, Linkify.ALL);
        return this;
    }

    public ViewHolder setTypeface(Typeface typeface, int... viewIds) {
        for (int viewId : viewIds) {
            TextView view = getView(viewId);
            view.setTypeface(typeface);
            view.setPaintFlags(view.getPaintFlags() | Paint.SUBPIXEL_TEXT_FLAG);
        }
        return this;
    }

    public ViewHolder setProgress(int viewId, int progress) {
        ProgressBar view = getView(viewId);
        view.setProgress(progress);
        return this;
    }

    public ViewHolder setProgress(int viewId, int progress, int max) {
        ProgressBar view = getView(viewId);
        view.setMax(max);
        view.setProgress(progress);
        return this;
    }

    public ViewHolder setMax(int viewId, int max) {
        ProgressBar view = getView(viewId);
        view.setMax(max);
        return this;
    }

    public ViewHolder setRating(int viewId, float rating) {
        RatingBar view = getView(viewId);
        view.setRating(rating);
        return this;
    }

    public ViewHolder setRating(int viewId, float rating, int max) {
        RatingBar view = getView(viewId);
        view.setMax(max);
        view.setRating(rating);
        return this;
    }

    public ViewHolder setTag(int viewId, Object tag) {
        View view = getView(viewId);
        view.setTag(tag);
        return this;
    }

    public ViewHolder setTag(int viewId, int key, Object tag) {
        View view = getView(viewId);
        view.setTag(key, tag);
        return this;
    }

    public ViewHolder setChecked(int viewId, boolean checked) {
        Checkable view = (Checkable) getView(viewId);
        view.setChecked(checked);
        return this;
    }

    /**
     * 关于事件的
     */
    public ViewHolder setOnClickListener(int viewId,
                                         View.OnClickListener listener) {
        View view = getView(viewId);
        view.setOnClickListener(listener);
        return this;
    }

    public ViewHolder setOnTouchListener(int viewId,
                                         View.OnTouchListener listener) {
        View view = getView(viewId);
        view.setOnTouchListener(listener);
        return this;
    }

    public ViewHolder setOnLongClickListener(int viewId,
                                             View.OnLongClickListener listener) {
        View view = getView(viewId);
        view.setOnLongClickListener(listener);
        return this;
    }

    public void updatePosition(int position) {
        mPosition = position;
    }

    public int getLayoutId() {
        return mLayoutId;
    }

    /**
     * 隐藏或展示Item
     *
     * @param visible
     */
    public void setItemVisible(boolean visible) {
        View v = getConvertView();
        if (null != v) {
            if (visible) {
                if (null != v.getLayoutParams()) {
                    v.getLayoutParams().width = AbsListView.LayoutParams.MATCH_PARENT;
                    v.getLayoutParams().height = AbsListView.LayoutParams.WRAP_CONTENT;
                } else {
                    v.setLayoutParams(new AbsListView.LayoutParams(AbsListView.LayoutParams.MATCH_PARENT, AbsListView.LayoutParams.WRAP_CONTENT));
                }
                v.setVisibility(View.VISIBLE);
            } else {
                if (null != v.getLayoutParams()) {
                    v.getLayoutParams().width = -1;
                    v.getLayoutParams().height = 1;
                } else {
                    v.setLayoutParams(new AbsListView.LayoutParams(-1, 1));
                }
                v.setVisibility(View.GONE);
            }
        }
    }

    public void setHItemVisible(boolean visible) {
        View v = getConvertView();
        if (null != v) {
            if (visible) {
                if (null != v.getLayoutParams()) {
                    v.getLayoutParams().width = AbsListView.LayoutParams.WRAP_CONTENT;
                    v.getLayoutParams().height = AbsListView.LayoutParams.WRAP_CONTENT;
                } else {
                    v.setLayoutParams(new AbsListView.LayoutParams(AbsListView.LayoutParams.MATCH_PARENT, AbsListView.LayoutParams.WRAP_CONTENT));
                }
                v.setVisibility(View.VISIBLE);
            } else {
                if (null != v.getLayoutParams()) {
                    v.getLayoutParams().width = -1;
                    v.getLayoutParams().height = 1;
                } else {
                    v.setLayoutParams(new AbsListView.LayoutParams(-1, 1));
                }
                v.setVisibility(View.GONE);
            }
        }
    }

}

使用

   mRv = (RecyclerView) findViewById(R.id.rv);
        mRv.setLayoutManager(mManager = new LinearLayoutManager(this));

        mAdapter = new CityAdapter(this, mDatas);
        mHeaderAdapter = new HeaderRecyclerAndFooterWrapperAdapter(mAdapter) {
            @Override
            protected void onBindHeaderHolder(ViewHolder holder, int headerPos, int layoutId, Object o) {
                holder.setText(R.id.tvCity, (String) o);
            }
        };
        mHeaderAdapter.setHeaderView(R.layout.item_city, "测试头部");

        mRv.setAdapter(mHeaderAdapter);
    原文作者:ProcessZ
    原文地址: https://www.jianshu.com/p/2851e77cc006
    本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。
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