我通过使用swift创建的API进行url调用，如下所示：
class API {
let apiEndPoint = "endpoint"
let apiUrl:String!
let consumerKey:String!
let consumerSecret:String!
var returnData = [:]
init(){
self.apiUrl = "https://myurl.com/"
self.consumerKey = "my consumer key"
self.consumerSecret = "my consumer secret"
}
func getOrders() -> NSDictionary{
return makeCall("orders")
}
func makeCall(section:String) -> NSDictionary{
let params = ["consumer_key":"key", "consumer_secret":"secret"]
Alamofire.request(.GET, "\(self.apiUrl)/\(self.apiEndPoint + section)", parameters: params)
.authenticate(user: self.consumerKey, password: self.consumerSecret)
.responseJSON { (request, response, data, error) -> Void in
println("error \(request)")
self.returnData = data! as NSDictionary
}
return self.returnData
}
}
我在UITableViewController中调用此API以使用SwiftyJSON库填充表。但是，API中的returnData始终为空。 Alomofire调用没有问题，因为我可以成功检索值。我的问题是我应该如何将这个data传递给我的表视图控制器？
var api = API()
api.getOrders()
println(api.returnData) // returnData is empty
答案 0 :(得分：93)
正如mattt所指出的，Alamofire通过“完成处理程序”模式异步返回数据，所以你必须这样做。您不能立即return该值，而是希望将您的方法更改为不返回任何内容，而是使用完成处理程序闭包模式。
如今，这可能看起来像：
func getOrders(completionHandler: @escaping (Result<[String: Any]>) -> Void) {
performRequest("orders", completion: completionHandler)
}
func performRequest(_ section: String, completion: @escaping (Result<[String: Any]>) -> Void) {
let url = baseURL.appendingPathComponent(section)
let params = ["consumer_key": "key", "consumer_secret": "secret"]
Alamofire.request(url, parameters: params)
.authenticate(user: consumerKey, password: consumerSecret)
.responseJSON { response in
switch response.result {
case .success(let value as [String: Any]):
completion(.success(value))
case .failure(let error):
completion(.failure(error))
default:
fatalError("received non-dictionary JSON response")
}
}
}
然后，当你想调用它时，你使用这个completion闭包参数（如果你想要的话，在尾随闭包中）：
api.getOrders { result in
switch result {
case .failure(let error):
print(error)
case .success(let value):
// use `value` here
}
}
// but don't try to use the `error` or `value`, as the above closure
// has not yet been called
//
答案 1 :(得分：13)
来自Alamofire README（重点补充）：
Alamofire中的网络是异步完成的。异步编程可能会让不熟悉这个概念的程序员感到沮丧，但是有很好的理由这样做。
不是阻止执行以等待来自服务器的响应，而是指定回调一旦收到响应就处理响应。 请求的结果仅在响应处理程序的范围内可用。根据响应或从服务器接收的数据执行的任何执行都必须在处理程序中完成。
答案 2 :(得分：3)
以下是使用Alamofire和Swift执行'登录操作'的完整流程。
Alamofire v3.3 Swift 2.2 Xcode 7.3
为了方便起见，我使用了 GCD 和 MBProgressHUD 。根据需要重构和使用：）
func loginBtnTapped(sender: AnyObject) {
MBProgressHUD.showHUDAddedTo(self.view, animated: true)
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
let loginInfo : Dictionary<String,AnyObject> = ["email":"abc@g.com","password":"abc123"]
self.loginUser(loginInfo) { responseObject, error in
print("\(responseObject) \n \(error) ")
// Parsing JSON Below
let status = Int(responseObject?.objectForKey("status") as! String)
if status == 1 {
// Login Successfull...Move To New VC
}
else {
print(responseObject?.objectForKey("message"))! as! String)
}
return
}
dispatch_async(dispatch_get_main_queue()) {
MBProgressHUD.hideHUDForView(self.view, animated: true)
}
}
}
func loginUser(parameters:NSDictionary, completionHandler: (NSDictionary?, NSError?) -> ()) {
self.postRequest("http://qa.company.com/project/index.php/user/login",
paramDict: parameters as? Dictionary<String, AnyObject>,
completionHandler: completionHandler)
}
func postRequest(urlString: String, paramDict:Dictionary<String, AnyObject>? = nil,
completionHandler: (NSDictionary?, NSError?) -> ()) {
Alamofire.request(.POST, urlString, parameters: paramDict)
.responseJSON { response in
switch response.result {
case .Success(let JSON):
completionHandler(JSON as? NSDictionary, nil)
case .Failure(let error):
completionHandler(nil, error)
}
}
}
答案 3 :(得分：2)
xCode 9.1，Swift 4
特点：
使用闭包
返回数据Data1.searchRequest(term: "jack johnson") { json, error in
print(error ?? "nil")
print(json ?? "nil")
print("Update views")
}
数据类
import Alamofire
class Data1 {
static fileprivate let queue = DispatchQueue(label: "requests.queue", qos: .utility)
static fileprivate let mainQueue = DispatchQueue.main
fileprivate class func make(request: DataRequest, closure: @escaping (_ json: [String: Any]?, _ error: Error?)->()) {
request.responseJSON(queue: Data1.queue) { response in
// print(response.request ?? "nil") // original URL request
// print(response.response ?? "nil") // HTTP URL response
// print(response.data ?? "nil") // server data
//print(response.result ?? "nil") // result of response serialization
switch response.result {
case .failure(let error):
Data1.mainQueue.async {
closure(nil, error)
}
case .success(let data):
Data1.mainQueue.async {
closure((data as? [String: Any]) ?? [:], nil)
}
}
}
}
class func searchRequest(term: String, closure: @escaping (_ json: [String: Any]?, _ error: Error?)->()) {
let request = Alamofire.request("https://itunes.apple.com/search?term=\(term.replacingOccurrences(of: " ", with: "+"))")
Data1.make(request: request) { json, error in
closure(json, error)
}
}
}
的UIViewController
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
Data1.searchRequest(term: "jack johnson") { json, error in
print(error ?? "nil")
print(json ?? "nil")
print("Update views")
}
}
}
使用委托
返回数据// ....
var data = Data2()
data.delegate = self
data.searchRequest(term: "jack johnson")
// ....
extension ViewController: Data2Delegate {
func searchRequest(response json: [String : Any]?, error: Error?) {
print(error ?? "nil")
print(json ?? "nil")
print("Update views")
}
}
数据类
import Alamofire
protocol Data2Delegate: class {
func searchRequest(response json: [String: Any]?, error: Error?)
}
class Data2 {
fileprivate let queue = DispatchQueue(label: "requests.queue", qos: .utility)
fileprivate let mainQueue = DispatchQueue.main
weak var delegate: Data2Delegate?
fileprivate func make(request: DataRequest, closure: @escaping (_ json: [String: Any]?, _ error: Error?)->()) {
request.responseJSON(queue: queue) { response in
// print(response.request ?? "nil") // original URL request
// print(response.response ?? "nil") // HTTP URL response
// print(response.data ?? "nil") // server data
//print(response.result ?? "nil") // result of response serialization
switch response.result {
case .failure(let error):
self.mainQueue.async {
closure(nil, error)
}
case .success(let data):
self.mainQueue.async {
closure((data as? [String: Any]) ?? [:], nil)
}
}
}
}
func searchRequest(term: String) {
let request = Alamofire.request("https://itunes.apple.com/search?term=\(term.replacingOccurrences(of: " ", with: "+"))")
make(request: request) { json, error in
self.delegate?.searchRequest(response: json, error: error)
}
}
}
的UIViewController
import UIKit
class ViewController: UIViewController {
private var data = Data2()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
data.delegate = self
data.searchRequest(term: "jack johnson")
}
}
extension ViewController: Data2Delegate {
func searchRequest(response json: [String : Any]?, error: Error?) {
print(error ?? "nil")
print(json ?? "nil")
print("Update views")
}
}
_ = data.searchRequest(term: "jack johnson").then { response in
print(response.error ?? "nil")
print(response.json ?? "nil")
print("Update views")
return .void
}
数据类 进口Alamofire 导入PromiseKit
class Data3 {
fileprivate let queue = DispatchQueue(label: "requests.queue", qos: .utility)
fileprivate let mainQueue = DispatchQueue.main
fileprivate func make(request: DataRequest) -> Promise<(json:[String: Any]?, error: Error?)> {
return Promise { fulfill, reject in
request.responseJSON(queue: queue) { response in
// print(response.request ?? "nil") // original URL request
// print(response.response ?? "nil") // HTTP URL response
// print(response.data ?? "nil") // server data
//print(response.result ?? "nil") // result of response serialization
switch response.result {
case .failure(let error):
self.mainQueue.async {
fulfill((nil, error))
}
case .success(let data):
self.mainQueue.async {
fulfill(((data as? [String: Any]) ?? [:], nil))
}
}
}
}
}
func searchRequest(term: String) -> Promise<(json:[String: Any]?, error: Error?)> {
let request = Alamofire.request("https://itunes.apple.com/search?term=\(term.replacingOccurrences(of: " ", with: "+"))")
return make(request: request)
}
}
extension AnyPromise {
class var void: AnyPromise {
return AnyPromise(Promise<Void>())
}
}
的UIViewController
import UIKit
import PromiseKit
class ViewController: UIViewController {
private var data = Data3()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
_ = data.searchRequest(term: "jack johnson").then { response in
print(response.error ?? "nil")
print(response.json ?? "nil")
print("Update views")
return .void
}
}
}
答案 4 :(得分：0)
要使用Swifty JSON解析json，我就是这样做的。
对于@Jenita _Alice4Real
<link rel="stylesheet" type="text/css" href="http://code.jquery.com/ui/1.9.2/themes/base/jquery-ui.css">
<script type="text/javascript" src="//code.jquery.com/jquery-1.9.1.js"></script>
<script type="text/javascript" src="//code.jquery.com/ui/1.9.2/jquery-ui.js"></script>
<link rel="stylesheet" type="text/css" href="//code.jquery.com/ui/1.9.2/themes/base/jquery-ui.css">
<input id="departure-date" type="text" placeholder="Depart Date" >
<input type="text" id="return-date" placeholder="return Date">