如何调试 ObservedObject 不再接收 Published 变量更改的原因？

Question

在我的应用程序中实施新功能后，我收到报告说我的搜索栏不再正常运行。进一步调试后，我将其缩小到 ObservedObject 没有收到来自我的 Published 变量的更改。

LocationHandler class 中的调试语句打印出来，我可以在不同的位置放置断点以获得 @Published 变量打印输出但是，当我放置断点时我使用 ObservedObject、locationHandler.lhLatitude 的 UIViewRepresentable 正在打印 0.0，我不确定为什么会这样。我很乐意继续对此进行进一步调试，但是我不确定如何继续进行此类调试。

class LocationHandler: ObservableObject {
    @Published var lhLatitude: Double
    @Published var lhLongitude: Double

    internal init(lhLatitude: Double, lhLongitude: Double) {
        self.lhLatitude = lhLatitude
        self.lhLongitude = lhLatitude
    }
    
    func changeRegion(searchArea: String) {
        let searchRequest = MKLocalSearch.Request()
        searchRequest.naturalLanguageQuery = searchArea
        
        let search = MKLocalSearch(request: searchRequest)
        search.start { (response, error) in
            guard let response = response else {
                // MARK: Consider an alert here or some sort of thing notice rather then having no resposne?
                return
            }
            
            let freshLocation = response.mapItems.first?.placemark.coordinate
            self.lhLatitude = freshLocation!.latitude
            self.lhLongitude = freshLocation!.longitude
            
            // MARK: Debugging.
            if (freshLocation!.latitude > 0.0) {
                print("Fresh Latitude: \(self.lhLatitude)")
                print("Fresh Longitude: \(self.lhLongitude)")
            }
        }
    } // End of changeRegion function.
}

// This is on a UIViewRepresentable.

    @ObservedObject var locationHandler: LocationHandler

// This is located in the updateView function and this is it's use-case, I've yet to have an issue with it until this immediate instance.
       if locationHandler.lhLongitude > (0.0) {
            print("Location Handler Latitude : \(locationHandler.lhLatitude)")
            view.setRegion(MKCoordinateRegion(center: CLLocationCoordinate2D(latitude: locationHandler.lhLatitude, longitude: locationHandler.lhLongitude), latitudinalMeters: defaultSpan, longitudinalMeters: defaultSpan), animated: true)
            // MARK: Debug
            print(#function)
        }

Answer 1

原因被确定为不当使用传递 MKCoordinateRegion 的状态。每次用户提交搜索时，它都会触发但会重新加载子视图，然后更改状态。

如何调试 ObservedObject 不再接收 Published 变量更改的原因？

How can I debug why an ObservedObject is no longer receiving a Published variable change?

uikit

ios

swift