从 Firestore Swift 在谷歌地图上显示多个位置

Question

我正在尝试在谷歌地图上显示位置，我从 Firestore 获取经度和纬度。

我创建了一个存储经纬度的结构

struct Location {

var latitude: String = ""
var longitute: String = ""
}

这是我获取经度和纬度的 Firestore 代码

for document in snapshot!.documents {
self.location.append(Location(latitude: "\(document.data()["Latitude"] ?? "")", longitute: "\(document.data()["longitude"] ?? "")"))
print(self.location)

    guard let long = document.data()["Latitude"] as? String else { return}
    guard let lat = document.data()["longitude"] as? String else { return}
    let markerStart = GMSMarker(position: CLLocationCoordinate2D(latitude: Double(long) ?? 0.0, longitude: Double(lat) ?? 0.0))
    markerStart.map = self.mapView
}

我在控制台中获取位置，但是当我将其转换为双打试图在谷歌地图上显示它时，它不起作用。请帮忙？

 Document Value is ["userid": 24xDkrtBV6cJrBvRD3U0PmyBF3o2, "createddatetime": FIRTimestamp: seconds=1546584489 nanoseconds=461000000>, "user_role": sales man, "Latitude": 20.6108261, "longitude": 72.9269003, "batterypercentage": 66, "name": Keyur , "company_code": 001]

Answer 1

所以你有这个数据：

["userid": 24xDkrtBV6cJrBvRD3U0PmyBF3o2, "createddatetime": FIRTimestamp: seconds=1546584489 nanoseconds=461000000>, "user_role": sales man, "Latitude": 20.6108261, "longitude": 72.9269003, "batterypercentage": 66, "name": Keyur , "company_code": 001]

代替这种代码：

for document in snapshot!.documents {
self.location.append(Location(latitude: "\(document.data()["Latitude"] ?? "")", longitute: "\(document.data()["longitude"] ?? "")"))
print(self.location)

    guard let long = document.data()["Latitude"] as? String else { return}
    guard let lat = document.data()["longitude"] as? String else { return}
    let markerStart = GMSMarker(position: CLLocationCoordinate2D(latitude: Double(long) ?? 0.0, longitude: Double(lat) ?? 0.0))
    markerStart.map = self.mapView
}

我们可以这样更好，

    for document in snapshot!.documents {
        self.location.append(Location(latitude: "\(document.data()["Latitude"] ?? "")", longitute: "\(document.data()["longitude"] ?? "")"))
        print(self.location)

        guard let latitude = document.data()["Latitude"] as? Double,
            let longitude = document.data()["Latitude"] as? Double else { return }

        let markerStart = GMSMarker(position: CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
        markerStart.map = self.mapView
    }

程序没有到达第 72 73 74 行的原因是因为guard let。它无法从您的document.data() 转换为您假定的Double 纬度和经度String。像我上面的代码那样做，然后你可以根据需要进一步改进它。