子组件的 animationfinish: function animationfinish(e) { console.log(e) console.log(this.data) var _data = this.data, _last = _data._last, _change = _data._change, curQueue = _data.curQueue, prevQueue = _data.prevQueue, nextQueue = _data.nextQueue; var current = e.detail.current; var diff = current - _last; if (diff === 0) return; this.data._last = current; this.playCurrent(current); this.triggerEvent('change', { activeId: curQueue[current].id }); var direction = diff === 1 || diff === -2 ? 'up' : 'down'; console.log(direction) if (direction === 'up') { if (this.data._invalidDown === 0) { var change = (_change + 1) % 3; var add = nextQueue.shift(); var remove = curQueue[change]; if (add) { prevQueue.push(remove); curQueue[change] = add; this.data._change = change; } else { this.data._invalidUp += 1; } } else { this.data._invalidDown -= 1; } } if (direction === 'down') { if (this.data._invalidUp === 0) { var _change2 = _change; //2 var _remove = curQueue[_change2]; var _add = prevQueue.pop(); if (_add) { curQueue[_change2] = _add; nextQueue.unshift(_remove); this.data._change = (_change2 - 1 + 3) % 3; } else { this.data._invalidDown += 1; } } else { this.data._invalidUp -= 1; } } var circular = true; if (nextQueue.length === 0 && current !== 0) { circular = false; } if (prevQueue.length === 0 && current !== 2) { circular = false; } this.setData({ curQueue: curQueue, circular: circular }); }, 这些属性都代表啥意思? _last: 1, _change: -1, _invalidUp: 0, _invalidDown: 0,