我在iBooks上读了苹果的编程语言Swift，但不知道如何在Swift中发出HTTP请求(类似cURL)。我需要导入Obj-C类还是只需要导入默认库?或者不能基于原生Swift代码进行HTTP请求?
当前回答
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()
其他回答
基本的Swift 3+解决方案
guard let url = URL(string: "http://www.stackoverflow.com") else { return }
let task = URLSession.shared.dataTask(with: url) { data, response, error in
guard let data = data, error == nil else { return }
print(NSString(data: data, encoding: String.Encoding.utf8.rawValue))
}
task.resume()
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()
你可以使用URL URLRequest URLSession或者NSURLConnection就像你在Objective-C中通常做的那样。注意，对于iOS 7.0及更高版本，URLSession是首选。
使用URLSession
初始化URL对象和URLSession中的URLSessionDataTask。然后使用resume()运行任务。
let url = URL(string: "http://www.stackoverflow.com")!
let task = URLSession.shared.dataTask(with: url) {(data, response, error) in
guard let data = data else { return }
print(String(data: data, encoding: .utf8)!)
}
task.resume()
使用NSURLConnection
首先，初始化URL和URLRequest:
let url = URL(string: "http://www.stackoverflow.com")!
var request = URLRequest(url: url)
request.httpMethod = "POST"
然后，你可以异步加载请求:
NSURLConnection.sendAsynchronousRequest(request, queue: OperationQueue.main) {(response, data, error) in
guard let data = data else { return }
print(String(data: data, encoding: .utf8)!)
}
或者你可以初始化一个NSURLConnection:
let connection = NSURLConnection(request: request, delegate:nil, startImmediately: true)
只是要确保将委托设置为nil以外的东西，并使用委托方法处理接收到的响应和数据。
要了解更多细节，请查看NSURLConnectionDataDelegate协议的文档
在Xcode操场上测试
如果你想在Xcode游乐场上尝试这段代码，添加import PlaygroundSupport到你的游乐场，以及下面的调用:
PlaygroundPage.current.needsIndefiniteExecution = true
这将允许你在操场上使用异步代码。
//这是一个对我有用的例子
//发送请求到服务器的Swift函数
func insertRecords()
{
let usrID = txtID.text
let checkin = lblInOut.text
let comment = txtComment.text
// The address of the web service
let urlString = "http://your_url/checkInOut_post.php"
// These are the keys that your are sending as part of the post request
let keyValues = "id=\(usrID)&inout=\(checkin)&comment=\(comment)"
// 1 - Create the session by getting the configuration and then
// creating the session
let config = NSURLSessionConfiguration.defaultSessionConfiguration()
let session = NSURLSession(configuration: config, delegate: nil, delegateQueue: nil)
// 2 - Create the URL Object
if let url = NSURL(string: urlString){
// 3 - Create the Request Object
var request = NSMutableURLRequest(URL: url)
request.HTTPMethod = "POST"
// set the key values
request.HTTPBody = keyValues.dataUsingEncoding(NSUTF8StringEncoding);
// 4 - execute the request
let taskData = session.dataTaskWithRequest(request, completionHandler: {
(data:NSData!, response:NSURLResponse!, error:NSError!) -> Void in
println("\(data)")
// 5 - Do something with the Data back
if (data != nil) {
// we got some data back
println("\(data)")
let result = NSString(data: data , encoding: NSUTF8StringEncoding)
println("\(result)")
if result == "OK" {
let a = UIAlertView(title: "OK", message: "Attendece has been recorded", delegate: nil, cancelButtonTitle: "OK")
println("\(result)")
dispatch_async(dispatch_get_main_queue()) {
a.show()
}
} else {
// display error and do something else
}
} else
{ // we got an error
println("Error getting stores :\(error.localizedDescription)")
}
})
taskData.resume()
}
}
PHP代码来获取键值
$empID = $_POST['id'];
$inOut = $_POST['inout'];
$comment = $_POST['comment'];
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!!
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