openLayers 避免地图 canvas 重复绘制

   this.$nextTick(() => {
        let mapNode = document.querySelector(".map"); // finds the class
        if (mapNode) {
          // 避免地图 canvas 重复绘制
          mapNode.innerHTML = "";
        }
        this.initialMap([this.form.longitude, this.form.latitude]);
      });