这是 vis.js 源代码的摘录。您会注意到它尝试做的第一件事是找到事件的中心值。
Timeline.prototype.getEventProperties = function (event) {
var clientX = event.center ? event.center.x : event.clientX;
var clientY = event.center ? event.center.y : event.clientY;
var x;
if (this.options.rtl) {
x = util.getAbsoluteRight(this.dom.centerContainer) - clientX;
} else {
x = clientX - util.getAbsoluteLeft(this.dom.centerContainer);
}
var y = clientY - util.getAbsoluteTop(this.dom.centerContainer);
var item = this.itemSet.itemFromTarget(event);
var group = this.itemSet.groupFromTarget(event);
var customTime = CustomTime.customTimeFromTarget(event);
var snap = this.itemSet.options.snap || null;
var scale = this.body.util.getScale();
var step = this.body.util.getStep();
var time = this._toTime(x);
var snappedTime = snap ? snap(time, scale, step) : time;
var element = util.getTarget(event);
var what = null;
if (item != null) {
what = 'item';
} else if (customTime != null) {
what = 'custom-time';
} else if (util.hasParent(element, this.timeAxis.dom.foreground)) {
what = 'axis';
} else if (this.timeAxis2 && util.hasParent(element, this.timeAxis2.dom.foreground)) {
what = 'axis';
} else if (util.hasParent(element, this.itemSet.dom.labelSet)) {
what = 'group-label';
} else if (util.hasParent(element, this.currentTime.bar)) {
what = 'current-time';
} else if (util.hasParent(element, this.dom.center)) {
what = 'background';
}
return {
event: event,
item: item ? item.id : null,
group: group ? group.groupId : null,
what: what,
pageX: event.srcEvent ? event.srcEvent.pageX : event.pageX,
pageY: event.srcEvent ? event.srcEvent.pageY : event.pageY,
x: x,
y: y,
time: time,
snappedTime: snappedTime
};
};
因此,您的问题很可能是由于没有为该方法提供有效事件。我相信这是因为您没有为 getEventProperties 方法提供任何参数。我会尝试类似的东西:
myDropCallback: function (event) {
console.log('value', this.$refs.timeline.getEventProperties(event))
},
此外,这里有一个很好的堆栈溢出帖子,由 vis.js 的一位作者回答:vis.js 时间轴如何将鼠标悬停事件添加到 vis-item box-box