上滑触发事件

      onTouchStart(event) {

            this.deltaY = 0;
            this.direction = '';
            this.startX = event.touches[0].clientX;
            this.startY = event.touches[0].clientY;
        },
        onTouchMove(event) {
            let ifBottom = this.ifAtBottom();
            this.direction = this.direction || this.getDirection(event.touches[0]);

            if (ifBottom && this.direction === 'vertical') {
                this.deltaY = event.touches[0].clientY - this.startY;
            }
        },
        onTouchEnd() {
            let ifBottom = this.ifAtBottom();
            if (!this.ifLoadMore) {
                if (ifBottom && this.deltaY && this.deltaY <= -50) {
                    if (this.activeTabIndex >= this.count - 1) {
                        return;
                    }
                    this.activeTabIndex += 1;
                    this.setScrollTop(this.bannerHeight);
                }

            }
}

getScrollTop () {
            let scrollTop = 0;
            if (document.documentElement && document.documentElement.scrollTop) {
                scrollTop = document.documentElement.scrollTop;
            } else if (document.body) {
                scrollTop = document.body.scrollTop;
            }
            return scrollTop;
        },
        setScrollTop (top) {
            if (document.documentElement && document.documentElement.scrollTop) {
                document.documentElement.scrollTop = top;
            } else if (document.body) {
                document.body.scrollTop = top;
            }
        },

// 上滑查看时继续加载 在scroll事件中处理