字典仅检索以前的值，而不用新值更新

Question

当我点击确实点击了标记时，它会为我提供当前标记，但是添加新标记时它不会追加，而是在添加了较新的子项之后将其追加。

  func mapView(_ mapView: GMSMapView, didTap marker: GMSMarker) -> Bool {
        DispatchQueue.main.async(execute: {
            self.infoWindow.removeFromSuperview()
            self.locationMarker = nil
            self.locationMarker = marker
            var markerData: NSDictionary?
            if let data = marker.userData! as? NSDictionary {
                markerData = data
            }
            print(markerData as Any)

            self.infoWindow.markData = markerData
            self.infoWindow = self.loadNiB()
            if let keyData = markerData?["key"] {
                self.keyDataStored = keyData
                markerData = nil
            }
            guard let location = self.locationMarker?.position else {
                print("locationMarker is nil")
                return
            }

            self.infoWindow.center = mapView.projection.point(for: location)
            self.infoWindow.center.y = self.infoWindow.center.y - self.sizeForOffset(view: self.infoWindow)
            UIView.transition(with: self.view, duration: 0.25, options: [.transitionCrossDissolve], animations: {
                self.view.addSubview(self.infoWindow)
            }, completion: nil) 
        return false
    }

print（markerData as Any）的结果是

Optional({
    Vote = 0;
    key = "-LVIje0829RH0EkwUuiz";
    latitude = "37.33233141";
    longitude = "-122.0312186";
})

针对大孩子

但是，如果我添加了新的孩子，则用xchild标记它，结果是

Optional({
    latitude = "37.49707671";
    longitude = "-122.31324792";
})

如果我再次添加了新孩子，我们假设它是ychild，那么xchild将被更新并成为

Optional({
        Vote = 0;
        key = "-LVICnM6l5TMdsqkpP70";
        latitude = "37.49707671";
        longitude = "-122.31324792";
    })

并且ychild会丢失投票和关键，直到添加新的