一个实现了「上拉加载」的SwipeRefreshLayout

public class RefreshLayout extends SwipeRefreshLayout implements AbsListView.OnScrollListener {

    private int mTouchSlop; //滑动最短距离
    private int mDownY; //按下时的Y坐标
    private int mLastY; //抬起时的Y坐标
    private boolean isLoading = false; //是否处于加载状态

    private ListView mListView; //布局内的ListView实例
    private View mListViewFooter; //上拉加载脚布局

    private OnLoadMoreListener onLoadMoreListener; //上拉加载监听

    public RefreshLayout(Context context) {
        this(context, null);
    }

    public RefreshLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
        mListViewFooter = LayoutInflater.from(context).inflate(R.layout.view_load_more_footer, null, false);
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        //初始化布局内的ListView对象
        if (mListView == null) {
            getListView();
        }
    }

    /**
     * 获取布局内的ListView对象
     */
    private void getListView() {
        int childCount = getChildCount();
        if (childCount > ) {
            View childView = getChildAt();
            if (childView instanceof ListView) {
                mListView = (ListView) childView;
                //设置滚动监听器给ListView, 使得滚动的情况下也可以自动加载
                mListView.setOnScrollListener(this);
            }
        }
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        final int action = ev.getAction();
        switch (action) {
            case MotionEvent.ACTION_DOWN:
                mDownY = (int) ev.getRawY();
                break;
            case MotionEvent.ACTION_MOVE:
                mLastY = (int) ev.getRawY();
                break;
            case MotionEvent.ACTION_UP:
                if (canLoadMore()) {
                    LoadMore();
                }
                break;
        }
        return super.dispatchTouchEvent(ev);
    }

    /**
     * 处理加载更多
     */
    private void LoadMore() {
        if (onLoadMoreListener != null) {
            //设置上拉加载时的状态
            setLoading(true);
            onLoadMoreListener.onLoadMore();
        }
    }

    /**
     * 设置上拉加载时的状态
     */
    public void setLoading(boolean loading) {
        isLoading = loading;
        if (isLoading) {
            mListView.addFooterView(mListViewFooter);
        } else {
            mListView.removeFooterView(mListViewFooter);
            mDownY = ;
            mLastY = ;
        }
    }

    /**
     * 是否满足上拉加载条件
     */
    private boolean canLoadMore() {
        return isBottom() && !isLoading && isPullUp();
    }

    /**
     * ListView是否滑倒最底部
     */
    private boolean isBottom() {
        if (mListView != null && mListView.getAdapter() != null) {
            return mListView.getLastVisiblePosition() == (mListView.getAdapter().getCount() - );
        }
        return false;
    }

    /**
     * 是否是上拉操作
     */
    private boolean isPullUp() {
        return mLastY ==  ? false : (mDownY - mLastY) >= mTouchSlop;
    }

    @Override
    public void onScrollStateChanged(AbsListView absListView, int i) {

    }

    @Override
    public void onScroll(AbsListView absListView, int i, int i1, int i2) {
        if (canLoadMore()) {
            LoadMore();
        }
    }

    /**
     * 上拉加载监听接口
     */
    public interface OnLoadMoreListener {
        void onLoadMore();
    }

    /**
     * 设置监听
     */
    public void setOnLoadMoreListener(OnLoadMoreListener listener) {
        this.onLoadMoreListener = listener;
    }
}