下面是一个非常简单的Swift 4在操场上的例子:

import UIKit
// run asynchronously in a playground
import PlaygroundSupport
PlaygroundPage.current.needsIndefiniteExecution = true

// create a url
let url = URL(string: "http://www.stackoverflow.com")

// create a data task
let task = URLSession.shared.dataTask(with: url!) { (data, response, error) in
    if error != nil {
        print("there's a problem")
    }
    print(String(data: data!, encoding: String.Encoding.utf8) ?? "")
}

//running the task w/ resume
task.resume()

使用URLSession + Swift

只是补充cezar的答案，如果你想使用苹果的URLSession类进行web请求，有多种方法来完成任务

简单的GET请求与URL 简单的GET请求与URL和参数 简单的GET请求与错误处理的URL 简单的POST请求与URL，参数与错误处理

1. 简单的GET请求与URL

func simpleGetUrlRequest()
    {
        let url = URL(string: "https://httpbin.org/get")!

        let task = URLSession.shared.dataTask(with: url) {(data, response, error) in
            guard let data = data else { return }
            print("The response is : ",String(data: data, encoding: .utf8)!)
            //print(NSString(data: data, encoding: String.Encoding.utf8.rawValue) as Any)
        }
        task.resume()
    }

注意:请确保您必须在pList中为http请求添加“NSAppTransportSecurity”键

<key>NSAppTransportSecurity</key>
<dict>
<key>NSAllowsArbitraryLoads</key>
<true/>
</dict>

2. 简单的GET请求与URL和参数

func simpleGetUrlWithParamRequest()
    {
        let url = URL(string: "https://www.google.com/search?q=peace")!
        
        let task = URLSession.shared.dataTask(with: url) {(data, response, error) in
            
            if error != nil || data == nil {
                print("Client error!")
                return
            }
            guard let response = response as? HTTPURLResponse, (200...299).contains(response.statusCode) else {
                print("Server error!")
                return
            }
            print("The Response is : ",response)
        }
        task.resume()
    }

3.简单的GET请求与错误处理的URL

func simpleGetUrlRequestWithErrorHandling()
    {
        let session = URLSession.shared
        let url = URL(string: "https://httpbin.org/get")!
        
        let task = session.dataTask(with: url) { data, response, error in
            
            if error != nil || data == nil {
                print("Client error!")
                return
            }
            
            guard let response = response as? HTTPURLResponse, (200...299).contains(response.statusCode) else {
                print("Server error!")
                return
            }
            
            guard let mime = response.mimeType, mime == "application/json" else {
                print("Wrong MIME type!")
                return
            }
            
            do {
                let json = try JSONSerialization.jsonObject(with: data!, options: [])
                print("The Response is : ",json)
            } catch {
                print("JSON error: \(error.localizedDescription)")
            }
            
        }
        task.resume()
    }

4. 简单的POST请求与URL，参数与错误处理。

func simplePostRequestWithParamsAndErrorHandling(){
        let configuration = URLSessionConfiguration.default
        configuration.timeoutIntervalForRequest = 30
        configuration.timeoutIntervalForResource = 30
        let session = URLSession(configuration: configuration)
        
        let url = URL(string: "https://httpbin.org/post")!
        
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.addValue("application/json", forHTTPHeaderField: "Accept")
        
        let parameters = ["username": "foo", "password": "123456"]
        
        do {
            request.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: .prettyPrinted)
        } catch let error {
            print(error.localizedDescription)
        }
        
        let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in
            
            if error != nil || data == nil {
                print("Client error!")
                return
            }
            
            guard let response = response as? HTTPURLResponse, (200...299).contains(response.statusCode) else {
                print("Oops!! there is server error!")
                return
            }
            
            guard let mime = response.mimeType, mime == "application/json" else {
                print("response is not json")
                return
            }
            
            do {
                let json = try JSONSerialization.jsonObject(with: data!, options: [])
                print("The Response is : ",json)
            } catch {
                print("JSON error: \(error.localizedDescription)")
            }
            
        })
        
        task.resume()
    }

谢谢你的建议!!

 var post:NSString = "api=myposts&userid=\(uid)&page_no=0&limit_no=10"

    NSLog("PostData: %@",post);

    var url1:NSURL = NSURL(string: url)!

    var postData:NSData = post.dataUsingEncoding(NSASCIIStringEncoding)!

    var postLength:NSString = String( postData.length )

    var request:NSMutableURLRequest = NSMutableURLRequest(URL: url1)
    request.HTTPMethod = "POST"
    request.HTTPBody = postData
    request.setValue(postLength, forHTTPHeaderField: "Content-Length")
    request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
    request.setValue("application/json", forHTTPHeaderField: "Accept")

    var reponseError: NSError?
    var response: NSURLResponse?

    var urlData: NSData? = NSURLConnection.sendSynchronousRequest(request, returningResponse:&response, error:&reponseError)

    if ( urlData != nil ) {
        let res = response as NSHTTPURLResponse!;

        NSLog("Response code: %ld", res.statusCode);

        if (res.statusCode >= 200 && res.statusCode < 300)
        {
            var responseData:NSString  = NSString(data:urlData!, encoding:NSUTF8StringEncoding)!

            NSLog("Response ==> %@", responseData);

            var error: NSError?

            let jsonData:NSDictionary = NSJSONSerialization.JSONObjectWithData(urlData!, options:NSJSONReadingOptions.MutableContainers , error: &error) as NSDictionary

            let success:NSInteger = jsonData.valueForKey("error") as NSInteger

            //[jsonData[@"success"] integerValue];

            NSLog("Success: %ld", success);

            if(success == 0)
            {
                NSLog("Login SUCCESS");

                self.dataArr = jsonData.valueForKey("data") as NSMutableArray
                self.table.reloadData()

            } else {

                NSLog("Login failed1");
                ZAActivityBar.showErrorWithStatus("error", forAction: "Action2")
            }

        } else {

            NSLog("Login failed2");
            ZAActivityBar.showErrorWithStatus("error", forAction: "Action2")

        }
    } else {

        NSLog("Login failed3");
        ZAActivityBar.showErrorWithStatus("error", forAction: "Action2")
}

它一定会对你有帮助

答:吻

URLSession.shared.dataTask(with: URL(string: "https://google.com")!) {(data, response, error) in
    print(String(data: data!, encoding: .utf8))
}.resume()

斯威夫特3.0

通过一个小抽象 https://github.com/daltoniam/swiftHTTP

例子

    do {
        let opt = try HTTP.GET("https://google.com")
        opt.start { response in
            if let err = response.error {
                print("error: \(err.localizedDescription)")
                return //also notify app of failure as needed
            }
            print("opt finished: \(response.description)")
            //print("data is: \(response.data)") access the response of the data with response.data
        }
    } catch let error {
        print("got an error creating the request: \(error)")
    }

你可以使用Just，一个python-requests风格的HTTP库。

使用Just发送HTTP请求的示例:

// synchronous GET request with URL query a=1
let r = Just.get("https://httpbin.org/get", params:["a":1])

// asynchronous POST request with form value and file uploads
Just.post(
    "http://justiceleauge.org/member/register",
    data: ["username": "barryallen", "password":"ReverseF1ashSucks"],
    files: ["profile_photo": .URL(fileURLWithPath:"flash.jpeg", nil)]
) { (r)
    if (r.ok) { /* success! */ }
}

在这两种情况下，可以通过类似于python-request的方式访问请求r的结果:

r.ok            // is the response successful?
r.statusCode    // status code of response
r.content       // response body as NSData?
r.text          // response body as text?
r.json          // response body parsed by NSJSONSerielization

你可以在这个操场上找到更多的例子

在操场上以同步模式使用这个库是Swift中最接近cURL的东西。