RecycleView下拉刷新控件的封装(包括下拉刷新和加载更多 ）

最近学习了RecycleView控件的使用，就尝试封装了RecycleView 下拉刷新控件，实现的功能有（下拉刷新和加载更多）

转载请注明原博客地址：http://blog.csdn.net/gdutxiaoxu/article/details/51473358

1 思路解析

1）我是通过继承LinearLayout来实现的，里面拥有SwipeRefreshLayout和RecycleView

2）下拉刷新是通过SwipeRefreshLayout设置监听器实现的

mSwipeRfl.setOnRefreshListener(mRefreshListener);

3）加载更多是通过监听RecycleView的OnScrollListener

mScrollListener = new RecyclerView.OnScrollListener() {    private int mLastVisibleItem;    private int mDy;    @Override    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {        super.onScrollStateChanged(recyclerView, newState);        if (newState != RecyclerView.SCROLL_STATE_IDLE) {            return;        }        //最后显示的项        mLastVisibleItem = mLayoutManager.findLastCompletelyVisibleItemPosition();        int totalItemCount = mLayoutManager.getItemCount();        /**         * 只有在下拉，并且没有早加载更多，并且允许加载更多，并且在最后一个条目，才调用加载更多的接口         */        if (mDy >= 0 && !isLoadMore && (mLastVisibleItem >= totalItemCount - 1) &&                enableLoadMore) {            loadMore();        }    }

2 下面给出源码

public class PulltoRefreshRecyclerView extends LinearLayout {    String Tag = "xujun";    /**     * 内容控件     */    private RecyclerView mRecyclerView;    /**     * 刷新布局控件     */    private SwipeRefreshLayout mSwipeRfl;    private LinearLayoutManager mLayoutManager;    /*     * 刷新布局的监听     */    private OnRefreshListener mRefreshListener;    /**     * 内容控件滚动监听     */    private RecyclerView.OnScrollListener mScrollListener;    /*     * 刷新加载监听事件     */    private onRefreshListener mRefreshLoadMoreListner;    /**     * 是否正在刷新     */    private boolean isRefresh = false;    /**     * 是否正在加载更多     */    private boolean isLoadMore = false;    private FrameLayout mFootView;    //    是否允许加载更多    private boolean enableLoadMore = true;    private int mMeasuredHeight;    public PulltoRefreshRecyclerView(Context context) {        this(context, null);    }    @SuppressWarnings("deprecation")    public PulltoRefreshRecyclerView(Context context, AttributeSet attrs) {        super(context, attrs);        // 导入布局        initView(context);        /**         * 监听上拉至底部滚动监听         */        initListener();        mRecyclerView.setHasFixedSize(true);        mLayoutManager = new LinearLayoutManager(context);        mRecyclerView.setLayoutManager(mLayoutManager);        mRecyclerView.setOnScrollListener(mScrollListener);    }    private void setFootViewHeight(int height) {        ViewGroup.LayoutParams layoutParams = mFootView.getLayoutParams();        layoutParams.height = height;        mFootView.setLayoutParams(layoutParams);    }    private void initListener() {        mScrollListener = new RecyclerView.OnScrollListener() {            private int mLastVisibleItem;            private int mDy;            @Override            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {                super.onScrollStateChanged(recyclerView, newState);                if (newState != RecyclerView.SCROLL_STATE_IDLE) {                    return;                }                //最后显示的项                mLastVisibleItem = mLayoutManager.findLastCompletelyVisibleItemPosition();                int totalItemCount = mLayoutManager.getItemCount();                /**                 * 只有在下拉，并且没有早加载更多，并且允许加载更多，并且在最后一个条目，才调用加载更多的接口                 */                if (mDy >= 0 && !isLoadMore && (mLastVisibleItem >= totalItemCount - 1) &&                        enableLoadMore) {                    loadMore();                }            }            @Override            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {                super.onScrolled(recyclerView, dx, dy);                mDy = dy;            }        };        /**         * 下拉至顶部刷新监听         */        mRefreshListener = new OnRefreshListener() {            @Override            public void onRefresh() {            /*    Log.i("Tag", "onRefresh1");                Log.i("Tag", isRefresh + "");                Log.i("Tag", isRefresh + "");                Log.i("Tag", isLoadMore + "");*/                LUtils.i("isLoadMore=" + isLoadMore);                if (!isRefresh && !isLoadMore) {//没有正在刷新或者正在加载更多                    isRefresh = true;                    refresh();                }            }        };        mSwipeRfl.setOnRefreshListener(mRefreshListener);    }    private void initView(Context context) {        View.inflate(context, R.layout.pulltorefreshrecyclerview,this);        mSwipeRfl = (SwipeRefreshLayout) findViewById(R.id.all_swipe);        mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);        initFootView();    }    private void initFootView() {        mFootView = (FrameLayout) findViewById(R.id.ll_load_more);        LUtils.i("mFootView=" +(mFootView==null));        mFootView.measure(0, 0);        mMeasuredHeight = mFootView.getMeasuredHeight();        setFootViewHeight(0);    }    public void setFooterView(View view) {        if (getFooterView() != null) {            getFooterView().removeAllViews();            mFootView.addView(view);        }    }    public FrameLayout getFooterView() {        return mFootView;    }    public RecyclerView getRecyclerView() {        return mRecyclerView;    }    public void setLayoutManager(LayoutManager layoutManager) {        if (mRecyclerView != null) {            mRecyclerView.setLayoutManager(layoutManager);        }    }    /**     * 设置是否允许下拉刷新     *     * @param enable     */    public void setPullRefreshEnable(boolean enable) {        setRefreshEnabled(enable);    }    public boolean getPullRefreshEnable() {        return mSwipeRfl.isEnabled();    }    public void setLoadMoreListener() {        mRecyclerView.setOnScrollListener(mScrollListener);    }    public void loadMore() {        if (mRefreshLoadMoreListner != null) {            isLoadMore = true;            //设置在加载更多的时候swipeLayout不允许加载更多，同时需要设置在加载更多完毕的时候允许swipeLayout加载更多            setRefreshEnabled(false);            mLayoutManager.scrollToPosition(mLayoutManager.findLastVisibleItemPosition());            showFootView();            mRefreshLoadMoreListner.onLoadMore(mRecyclerView);        }    }    public void setRefreshEnabled(boolean enabled) {        mSwipeRfl.setEnabled(enabled);    }    private void showFootView() {        setFootViewHeight(mMeasuredHeight);    }    public void OnRefreshCompleted() {        if (isRefresh) {//如果是正在刷新，就调用这个方法            stopRefresh();        } else if (isLoadMore) {//如果是正在加载更多，就调用这个方法            setLoadMoreCompleted();        }    }    /**     * 加载更多完毕,为防止频繁网络请求,isLoadMore为false才可再次请求更多数据     */    private void setLoadMoreCompleted() {//因为在加载更多的时候设置swipeLayout不允刷新，// 所以加载更多完毕的时候需要设置允许swipeLayout允许刷新        setRefreshEnabled(true);        isLoadMore = false;        hideFootView();    }    private void hideFootView() {//        setFootViewHeight(0);        rollbackFootView(mFootView);    }    private void stopRefresh() {        isRefresh = false;        mSwipeRfl.setRefreshing(false);    }    public void setOnRefreshListener(onRefreshListener listener) {        mRefreshLoadMoreListner = listener;    }    public void refresh() {        if (mRefreshLoadMoreListner != null) {            mRefreshLoadMoreListner.onRefresh(mRecyclerView);        }    }    public void setAdapter(RecyclerView.Adapter adapter) {        if (adapter != null)            mRecyclerView.setAdapter(adapter);    }    public interface onRefreshListener {        public void onRefresh(RecyclerView recyclerView);        public void onLoadMore(RecyclerView recyclerView);    }    /**     * 回滚下拉刷新头部控件     */    private void rollbackFootView(View view) {        final ValueAnimator rbAnimator = ValueAnimator.ofInt(0, mMeasuredHeight);        rbAnimator.setDuration(800);        rbAnimator.setInterpolator(new AccelerateDecelerateInterpolator());        rbAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {            @Override            public void onAnimationUpdate(ValueAnimator animation) {                float animatedFraction = animation.getAnimatedFraction();                /**                 * 当刷新完毕后，进行headerView的隐藏                 */                setFootViewHeight((int) (mMeasuredHeight - animatedFraction * mMeasuredHeight));            }        });        rbAnimator.addListener(new AnimatorListenerAdapter() {            @Override            public void onAnimationEnd(Animator animation) {                rbAnimator.removeAllListeners();            }        });        rbAnimator.start();    }    public boolean isLoadMore() {        return isLoadMore;    }    public boolean isRefresh() {        return isRefresh;    }    public boolean isEnableLoadMore() {        return enableLoadMore;    }}

3 存在的问题

1）在判断是够加载更多的时候 需要mLastVisibleItem 

/** * 只有在下拉，并且没有早加载更多，并且允许加载更多，并且在最后一个条目，才调用加载更多的接口 */if (mDy >= 0 && !isLoadMore && (mLastVisibleItem >= totalItemCount - 1) &&        enableLoadMore) {    loadMore();}

//最后显示的项mLastVisibleItem = mLayoutManager.findLastCompletelyVisibleItemPosition();但是findLastCompletelyVisibleItemPosition()这个方法是LinearLayoutManger里面的 方法 ，LinearLayoutManger的父类里面 RecyclerView.LayoutManager没有这个方法findLastCompletelyVisibleItemPosition()；这样导致我们 无法动态更改我们当前RecycleView实例的 LayoutManger

2）暂时没有实现SwipeLayoutProgress下拉刷新显示进度条 离我们第一个item之间的距离，可以参考
http://www.cnblogs.com/sunzn/p/3795009.html

3）暂时没有实现自定义属性，使用起来没有那么方便

4）源码下载地址：https://github.com/gdutxiaoxu/RecycleViewDemo