我是 Here iOS SDK 的新手,我正在尝试通过搜索某个位置周围的地点来使用地点 API。我做了一个 pod try HEREMapsStarter
并尝试了以下代码:
let places = NMAPlaces()
let location = NMAGeoCoordinates(latitude: yyy, longitude: xxx)
let result2 = places.makeSearchRequest(location: location, query: "restaurant")
let result = places.makeHereRequest(location: location, filters: nil)
result?.start(listener: self)
result2?.start(listener: self)
但这行不通,因为 result 和 result2 都是 nil。我在这里缺少什么?
最佳答案
看来您正在尝试创建 places 对象:
let places = NMAPlaces()
但是 places 对象是单例的,只能通过调用 shared() 来获取
let places = NMAPlaces.shared()
此外,当您使用 result?.start(listener: self)
方法时,您需要实现 NMAResultListener 监听器。简单监听器示例:
class MainViewController: UIViewController, NMAResultListener {
func requestDidComplete(_ request: NMARequest, data: Any?, error inError: Error?) {
print("data = \(String(describing: data))")
guard inError == nil else {
print ("Request error \((inError! as NSError).code)")
return
}
guard data is NMADiscoveryPage, let resultPage = data as? NMADiscoveryPage else {
print ("invalid type returned \(String(describing: data))")
return
}
let resultsArray: [NMALink] = resultPage.discoveryResults;
for link in resultsArray
{
if let placeLink = link as? NMAPlaceLink {
print("PlaceLink position: \(placeLink.position.latitude), \(placeLink.position.longitude)")
}
}
}
....
}
============================================= =====================
假设您正在英国伦敦 (51.514545,-0.131666) 进行搜索,并如上所述使用 NMAResultListener。在这两个请求中,监听器参数 self
实现 NMAResultListener,如上所述。
makeSearchRequest 的代码可能是下一个:
let geoCoordCenter = NMAGeoCoordinates(latitude:51.514545, longitude: -0.131666)
let searchRequest = NMAPlaces.shared().makeSearchRequest(location: geoCoordCenter, query: "restaurant")
searchRequest?.start(listener: self)
当请求完成时,makeSearchRequest 将返回结果:
data = Optional(<NMADiscoveryPage: 0x28241a400>)
PlaceLink position: 51.5117, -0.12565
PlaceLink position: 51.51312, -0.13374
....
PlaceLink position: 51.51371, -0.13155
PlaceLink position: 51.51462, -0.12651
以及 makeHereRequest 的代码:
let geoCoordCenter = NMAGeoCoordinates(latitude:51.514545, longitude: -0.131666)
let hereRequest = NMAPlaces.shared().makeHereRequest(location: geoCoordCenter, filters: nil)
hereRequest?.start(listener: self)
makeHereRequest 将返回结果:
data = Optional(<NMADiscoveryPage: 0x282400f00>)
PlaceLink position: 51.514542, -0.131883
PlaceLink position: 51.514542, -0.131883
....
PlaceLink position: 51.51435, -0.13169
PlaceLink position: 51.51444, -0.13194
PlaceLink position: 51.51444, -0.13194
另请注意,根据网络条件和搜索位置,也可能会出现错误结果,例如 not found
或其他错误。
关于ios - 这里 iOS SDK : Places API make*Request always returns nil,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/56767998/