加上if判斷，先判斷是否存在，否則不執行
this.getTitleTopY = debounce(() => {
if (this.$refs.param && this.$refs.comment && this.$refs.goodsList) {
this.$nextTick(() => {
//獲取不同組件的offsetTop
this.titleTopY = [];
this.titleTopY.push(0);
this.titleTopY.push(this.$refs.param.$el.offsetTop - 44);
this.titleTopY.push(this.$refs.comment.$el.offsetTop - 44);
this.titleTopY.push(this.$refs.goodsList.$el.offsetTop - 44);
this.titleTopY.push(Number.MAX_VALUE);
console.log("我");
});
}
}, 500);