1、主要用到下面四个方法。

2、方法开源于 鸿洋_ 的这篇文章 Android 优雅的为RecyclerView添加HeaderView和FooterView

大神是通过类似装饰者模式，去设计一个类，在不改变原有的Adapter基础上去增强其功能，使其支持addHeaderView和addFooterView。

3、而此篇文章是直接对RecyclerView.Adapter动手，使其支持addHeaderView和addFooterView，removeHeaderView和removeFooterView。

4、原理大神已给出，直接代码。直接继承此adapter即可。

import java.util.List; import android.content.Context; 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; import com.huahan.readerviewpager.adapter.ViewHolder; /** * Created by android.mtj on 2017/4/1. */ public abstract class BaseRecyclerViewAdapter<T> extends RecyclerView.Adapter<ViewHolder> { private static final int BASE_ITEM_TYPE_HEADER = 100000; private static final int BASE_ITEM_TYPE_FOOTER = 200000; private SparseArrayCompat<View> mHeaderViews = new SparseArrayCompat<>(); private SparseArrayCompat<View> mFootViews = new SparseArrayCompat<>(); private Context context; private List<T> list; public BaseRecyclerViewAdapter(Context context, List<T> list) { this.context = context; this.list = list; } @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { ViewHolder holder = null; if (mHeaderViews.get(viewType) != null) { holder = ViewHolder.createViewHolder(context, mHeaderViews.get(viewType)); } else if (mFootViews.get(viewType) != null) { holder = ViewHolder.createViewHolder(context, mFootViews.get(viewType)); } else { holder = ViewHolder.createViewHolder(context, parent, getViewHolderLaoutId()); } return holder; } /** * 获取ViewHolder layoutID * * @return */ protected abstract int getViewHolderLaoutId(); /** * 绑定ViewHolder */ @Override public void onBindViewHolder(ViewHolder holder, int position) { if (!(isHeaderViewPos(position) || isFooterViewPos(position))) { bindViewHolderData(holder, position); } } /** * 子类实现绑定ViewHolder * * @param holder * @param position */ protected abstract void bindViewHolderData(ViewHolder holder, int position); /** * 获取数据 * * @return */ public List<T> getListData() { return list; } /** * 获取总条目 */ @Override public int getItemCount() { return getHeadersCount() + getRealItemCount() + getFootersCount(); } /** * 判断是否是头部 * * @param position * @return */ private boolean isHeaderViewPos(int position) { return position < getHeadersCount(); } /** * 判断是否是底部 * * @param position * @return */ private boolean isFooterViewPos(int position) { return position >= getHeadersCount() + getRealItemCount(); } /** * 添加头部 * * @param view */ public void addHeaderView(View view) { mHeaderViews.put(mHeaderViews.size() + BASE_ITEM_TYPE_HEADER, view); } /** * 添加底部 * * @param view */ public void addFootView(View viewid) { mFootViews.put(mFootViews.size() + BASE_ITEM_TYPE_FOOTER, viewid); } /** * 获取数据条目 * * @return */ public int getRealItemCount() { return list.size(); } /** * 获取头部条目 * * @return */ public int getHeadersCount() { return mHeaderViews.size(); } /** * 获取底部条目 * * @return */ public int getFootersCount() { return mFootViews.size(); } /** * 移除第 i 个头部（0开始） * * @param i */ public void removeHeaderView(int i) { if (mHeaderViews.get(BASE_ITEM_TYPE_HEADER + i) != null) { mHeaderViews.remove(BASE_ITEM_TYPE_HEADER + i); } } /** * 移除第 i 个底部（0开始） * * @param i */ public void removeFooterView(int i) { if (mFootViews.get(BASE_ITEM_TYPE_FOOTER + i) != null) { mFootViews.remove(BASE_ITEM_TYPE_FOOTER + i); } } @Override public int getItemViewType(int position) { if (isHeaderViewPos(position)) { return mHeaderViews.keyAt(position); } else if (isFooterViewPos(position)) { return mFootViews.keyAt(position - getHeadersCount() - getRealItemCount()); } return position - getHeadersCount(); } /** * GridLayoutManager 时，头部和底部都要占据整行 * * @param recyclerView */ @Override public void onAttachedToRecyclerView(RecyclerView recyclerView) { super.onAttachedToRecyclerView(recyclerView); if (recyclerView == null) { return; } final RecyclerView.LayoutManager layoutManager = recyclerView .getLayoutManager(); if (layoutManager instanceof GridLayoutManager) { ((GridLayoutManager) layoutManager) .setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() { @Override public int getSpanSize(int position) { return (isHeaderViewPos(position) || isFooterViewPos(position)) ? ((GridLayoutManager) layoutManager) .getSpanCount() : 1; } }); } } /** * StaggeredGridLayoutManager 时，头部和底部都要占据整行 * * @param holder */ @Override public void onViewAttachedToWindow(ViewHolder holder) { super.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); } } } }

5、文中用到的ViewHolder的封装

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.Checkable; import android.widget.ImageView; import android.widget.ProgressBar; import android.widget.RatingBar; import android.widget.TextView; public class ViewHolder extends RecyclerView.ViewHolder { private SparseArray<View> mViews; private View mConvertView; private Context mContext; public ViewHolder(Context context, View itemView) { super(itemView); mContext = context; mConvertView = itemView; mViews = new SparseArray<View>(); } public static ViewHolder createViewHolder(Context context, View itemView) { ViewHolder holder = new ViewHolder(context, itemView); return holder; } public static ViewHolder createViewHolder(Context context, ViewGroup parent, int layoutId) { View itemView = LayoutInflater.from(context).inflate(layoutId, parent, false); ViewHolder holder = new ViewHolder(context, itemView); 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; } /**** 以下为辅助方法 *****/ /** * 获取控件 */ public ImageView getImageView(int viewId) { ImageView iv = getView(viewId); return iv; } public TextView getTextView(int viewId) { TextView tv = getView(viewId); return tv; } /** * 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 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; } }