【发布时间】：2020-03-30 07:54:59
【问题描述】：
我正在尝试找出正确的语法（或者我哪里出错了？）以显示返回的多嵌套 json，其中包含包含更多对象的数组。
我可以设法让嵌套对象工作，但在尝试获取数组中的对象时出现错误。
这是我的结构：
import Foundation
struct spaceXLaunch: Codable {
var flight_number: Int
var mission_name: String?
var launch_date_local: String?
var rocket: rocketResponse
var launch_site: launchSiteResponse
var links: linksResponse
var launch_success: Bool?
var details: String?
}
extension spaceXLaunch: Identifiable {
var id: Int { return flight_number }
}
struct rocketResponse: Codable {
var rocket_name: String
var rocket_id: String
var first_stage: firstStageResponse
var second_stage: secondStageResponse
}
struct firstStageResponse: Codable {
var cores: [coresResponse]
}
struct coresResponse: Codable {
var landing_vehicle: String?
var land_success: Bool?
var reused: Bool?
var landing_type: String?
}
struct secondStageResponse: Codable {
var payloads: [payloadsResponse]
}
struct payloadsResponse: Codable {
var payload_id: String?
var payload_type: String?
var payload_mass_kg: Double?
}
struct launchSiteResponse: Codable {
var site_name: String
}
struct linksResponse: Codable {
var missionPatch: String?
var missionPatchSml: String?
private enum CodingKeys: String, CodingKey {
case missionPatch = "mission_patch"
case missionPatchSml = "mission_patch_small"
}
}
这是我用来渲染视图的 SwiftUI 代码
import SwiftUI
struct listView: View {
@ObservedObject var fetcher = LaunchDataFetcher()
var body: some View {
List(fetcher.launches) { spaceXLaunch in
VStack (alignment: .leading) {
Text(spaceXLaunch.mission_name ?? "No Data Found")
Spacer()
Text(spaceXLaunch.details ?? "No Data Found")
.font(.system(size: 11))
Spacer()
Text(spaceXLaunch.launch_date_local ?? "No Data Found")
Spacer()
Text(spaceXLaunch.rocket.rocket_name)
Spacer()
///This line below comes back with an error of "Cannot subscript a value of incorrect or ambiguous type"
Text(spaceXLaunch.rocket.first_stage.cores[0].landing_type)
Spacer()
}
}
}
}
struct listView_Previews: PreviewProvider {
static var previews: some View {
listView()
.environment(\.colorScheme, .dark)
}
}
这里是为 api 返回的 Json 数据示例
{
"flight_number": 24,
"mission_name": "CRS-7",
"mission_id": [
"EE86F74"
],
"launch_year": "2015",
"launch_date_unix": 1435501260,
"launch_date_utc": "2015-06-28T14:21:00.000Z",
"launch_date_local": "2015-06-28T10:21:00-04:00",
"is_tentative": false,
"tentative_max_precision": "hour",
"tbd": false,
"launch_window": 0,
"rocket": {
"rocket_id": "falcon9",
"rocket_name": "Falcon 9",
"rocket_type": "v1.1",
"first_stage": {
"cores": [
{
"core_serial": "B1018",
"flight": 1,
"block": 1,
"gridfins": true,
"legs": true,
"reused": false,
"land_success": null,
"landing_intent": true,
"landing_type": "ASDS",
"landing_vehicle": "OCISLY"
}
]
},
"second_stage": {
"block": 1,
"payloads": [
{
"payload_id": "CRS-7",
"norad_id": [],
"reused": false,
"cap_serial": "C109",
"customers": [
"NASA (CRS)"
],
"nationality": "United States",
"manufacturer": "SpaceX",
"payload_type": "Dragon 1.1",
"payload_mass_kg": 2477,
"payload_mass_lbs": 5460.9,
"orbit": "ISS",
"orbit_params": {
"reference_system": "geocentric",
"regime": "low-earth",
"longitude": null,
"semi_major_axis_km": null,
"eccentricity": null,
"periapsis_km": null,
"apoapsis_km": null,
"inclination_deg": 51.6,
"period_min": null,
"lifespan_years": null,
"epoch": null,
"mean_motion": null,
"raan": null,
"arg_of_pericenter": null,
"mean_anomaly": null
},
"mass_returned_kg": null,
"mass_returned_lbs": null,
"flight_time_sec": 139,
"cargo_manifest": "https://www.nasa.gov/sites/default/files/atoms/files/spacex_crs-7_mission_overview.pdf",
"uid": "UerI6qmZTU2Fx2efDFm3QQ=="
}
]
},
"fairings": null
},
"ships": [
"ELSBETH3",
"GOQUEST",
"GOSEARCHER"
],
"telemetry": {
"flight_club": null
},
"launch_site": {
"site_id": "ccafs_slc_40",
"site_name": "CCAFS SLC 40",
"site_name_long": "Cape Canaveral Air Force Station Space Launch Complex 40"
},
"launch_success": false,
"launch_failure_details": {
"time": 139,
"altitude": 40,
"reason": "helium tank overpressure lead to the second stage LOX tank explosion"
},
"links": {
"mission_patch": "https://images2.imgbox.com/47/39/stH98Qy1_o.png",
"mission_patch_small": "https://images2.imgbox.com/d0/22/gyTVYo21_o.png",
"reddit_campaign": null,
"reddit_launch": "https://www.reddit.com/r/spacex/comments/3b27hk",
"reddit_recovery": null,
"reddit_media": "https://www.reddit.com/r/spacex/comments/3berj3",
"presskit": "https://www.nasa.gov/sites/default/files/atoms/files/spacex_nasa_crs-7_presskit.pdf",
"article_link": "https://spaceflightnow.com/2015/06/28/falcon-9-rocket-destroyed-in-launch-mishap/",
"wikipedia": "https://en.wikipedia.org/wiki/SpaceX_CRS-7",
"video_link": "https://www.youtube.com/watch?v=PuNymhcTtSQ",
"youtube_id": "PuNymhcTtSQ",
"flickr_images": [
"https://farm1.staticflickr.com/344/19045370790_f20f29cd8d_o.jpg",
"https://farm1.staticflickr.com/287/18999110808_6e153fed64_o.jpg"
]
},
"details": "Launch performance was nominal until an overpressure incident in the second-stage LOX tank, leading to vehicle breakup at T+150 seconds. The Dragon capsule survived the explosion but was lost upon splashdown because its software did not contain provisions for parachute deployment on launch vehicle failure.",
"upcoming": false,
"static_fire_date_utc": "2015-06-26T05:00:00.000Z",
"static_fire_date_unix": 1435294800,
"timeline": {
"webcast_liftoff": 61,
"go_for_prop_loading": -2280,
"rp1_loading": -2100,
"stage1_lox_loading": -2100,
"stage2_lox_loading": -960,
"engine_chill": -420,
"prelaunch_checks": -60,
"propellant_pressurization": -60,
"go_for_launch": -45,
"ignition": -3,
"liftoff": 0,
"maxq": 60,
"meco": 180,
"stage_sep": 180,
"second_stage_ignition": 180,
"seco-1": 540,
"dragon_separation": 600,
"dragon_solar_deploy": 720,
"dragon_bay_door_deploy": 8400
},
"crew": null
},
【问题讨论】：
-
尝试添加?? "" 在错误行中，因为它也是可选的
标签： arrays json xcode swiftui swift5