swift - 有人可以找到错误并验证我的 Swift NSURLSession 代码吗？

Question

我正在使用 Swift 编写我的第一个基本 IOS 应用程序，它将轮询 Proliphix IP 恒温器并显示温度。我已经使用 Paw 将 HTTP Post 转换为 NSURLSession，但是当我在 Xcode Playground 中加载转换后的代码时，它似乎有 3 个语法错误。

我现在的目标是让它在 Playground 中运行，但最终在我的应用程序代码中使用它。有人可以在您自己的 Xcode Playground 中加载此代码并修复错误并使其正常工作吗？该 URL 是恒温器的公共(public) IP 地址，如果工作正常，它将轮询恒温器并返回 OID4.3.2.3 和 = 类似 772& 的值(当前为 77.2 度)。

class MyRequestController {
    func sendRequest() {
        /* Configure session, choose between:
           * defaultSessionConfiguration
           * ephemeralSessionConfiguration
           * backgroundSessionConfigurationWithIdentifier:
         And set session-wide properties, such as: HTTPAdditionalHeaders,
         HTTPCookieAcceptPolicy, requestCachePolicy or timeoutIntervalForRequest.
         */
        let sessionConfig = NSURLSessionConfiguration.defaultSessionConfiguration()

        /* Create session, and optionally set a NSURLSessionDelegate. */
        let session = NSURLSession(configuration: sessionConfig, delegate: nil, delegateQueue: nil)

        /* Create the Request:
           My API (POST http://my-thermostat.dyndns.org:8083/get)
         */

        var URL = NSURL(string: "http://my-thermostat.dyndns.org:8083/get")
        let request = NSMutableURLRequest(URL: URL!)
        request.HTTPMethod = "POST"

        // Headers

        request.addValue("Basic dXNlcjpwYXNzd29yZA==", forHTTPHeaderField: "Authorization")

        // Form URL-Encoded Body

        let bodyParameters = [
            "OID4.3.2.3": "",
        ]
        let bodyString = self.stringFromQueryParameters(bodyParameters)
        request.HTTPBody = bodyString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)

        /* Start a new Task */
        let task = session.dataTaskWithRequest(request, completionHandler: { (data : NSData!, response : NSURLResponse!, error : NSError!) -> Void in
            if (error == nil) {
                // Success
                let statusCode = (response as NSHTTPURLResponse).statusCode
                println("URL Session Task Succeeded: HTTP \(statusCode)")
            }
            else {
                // Failure
                println("URL Session Task Failed: %@", error.localizedDescription);
            }
        })
        task.resume()
    }

    /**
     This creates a new query parameters string from the given NSDictionary. For
     example, if the input is @{@"day":@"Tuesday", @"month":@"January"}, the output
     string will be @"day=Tuesday&month=January".
     @param queryParameters The input dictionary.
     @return The created parameters string.
    */
    func stringFromQueryParameters(queryParameters : Dictionary<String, String>) -> String {
        var parts: [String] = []
        for (name, value) in queryParameters {
            var part = NSString(format: "%@=%@",
                name.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!,
                value.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!)
            parts.append(part)
        }
        return "&".join(parts)
    }

    /**
     Creates a new URL by adding the given query parameters.
     @param URL The input URL.
     @param queryParameters The query parameter dictionary to add.
     @return A new NSURL.
    */
    func NSURLByAppendingQueryParameters(URL : NSURL!, queryParameters : Dictionary<String, String>) -> NSURL {
        let URLString : NSString = NSString(format: "%@?%@", URL.absoluteString!, self.stringFromQueryParameters(queryParameters))
        return NSURL(string: URLString)!
    }
}

我假设我需要在 Playground 中使用此代码上方的以下内容才能正常工作？

import Foundation
import XCPlayground

最后，我用来转换的 HTTP Post 来自以下内容，Paw 将其转换为上面的 NSURLSession。

POST /get HTTP/1.1
Authorization: Basic dXNlcjpwYXNzd29yZA==
Content-Type: application/x-www-form-urlencoded
Host: my-thermostat.dyndns.org:8083
Connection: close
User-Agent: Paw/2.2.2 (Macintosh; OS X/10.10.4) GCDHTTPRequest
Content-Length: 11

OID4.3.2.3=

感谢您的帮助!

Answer 1

如果我使用您的代码创建一个 Playground ，我会收到三个错误。

函数 sendRequest() 中的一个，您必须更改此行:

let statusCode =(响应为 NSHTTPURLResponse).statusCode

到

let statusCode = (response as!NSHTTPURLResponse).statusCode

(as!而不是as)

函数 stringFromQueryParameters 中的一个，您必须更改以下行

parts.append(part)

至

parts.append(part as String)

(添加作为字符串)

函数 NSURLByAppendingQueryParameters 中的一个必须更改:

返回 NSURL(string: URLString)!

对此:

返回 NSURL(string: URLString as String)!

(添加作为字符串)

然后编译器似乎很满意......至少在我的机器上:-)

是的，您需要导入 Foundation 和 XCPlayground，正如您已经想到的那样。

此外，如果您需要进行异步调用...就像这里的情况一样，您需要在代码顶部使用此方法:

XCPSetExecutionShouldContinueIndefinitely()

(您可以阅读更多相关信息 here )

最后，要实际查看代码运行，您可以将其添加到代码底部的类定义之后:

let requestController = MyRequestController()
requestController.sendRequest()

这是完整的代码

import Foundation
import XCPlayground

XCPSetExecutionShouldContinueIndefinitely()

class MyRequestController {
    func sendRequest() {
        /* Configure session, choose between:
        * defaultSessionConfiguration
        * ephemeralSessionConfiguration
        * backgroundSessionConfigurationWithIdentifier:
        And set session-wide properties, such as: HTTPAdditionalHeaders,
        HTTPCookieAcceptPolicy, requestCachePolicy or timeoutIntervalForRequest.
        */
        let sessionConfig =   NSURLSessionConfiguration.defaultSessionConfiguration()

        /* Create session, and optionally set a NSURLSessionDelegate. */
        let session = NSURLSession(configuration: sessionConfig, delegate: nil, delegateQueue: nil)

        /* Create the Request:
        My API (POST http://my-thermostat.dyndns.org:8083/get)
        */

        var URL = NSURL(string: "http://my-thermostat.dyndns.org:8083/get")
        let request = NSMutableURLRequest(URL: URL!)
        request.HTTPMethod = "POST"

       // Headers

        request.addValue("Basic dXNlcjpwYXNzd29yZA==", forHTTPHeaderField: "Authorization")

        // Form URL-Encoded Body

        let bodyParameters = [
            "OID4.3.2.3": "",
         ]
        let bodyString = self.stringFromQueryParameters(bodyParameters)
        request.HTTPBody = bodyString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)

        /* Start a new Task */
        let task = session.dataTaskWithRequest(request, completionHandler: { (data : NSData!, response : NSURLResponse!, error : NSError!) -> Void in
            if (error == nil) {
                // Success
                let statusCode = (response as! NSHTTPURLResponse).statusCode
                println("URL Session Task Succeeded: HTTP \(statusCode)")
            }
            else {
                // Failure
                println("URL Session Task Failed: %@", error.localizedDescription);
            }
        })
        task.resume()
    }

    /**
    This creates a new query parameters string from the given NSDictionary. For
    example, if the input is @{@"day":@"Tuesday", @"month":@"January"}, the output
    string will be @"day=Tuesday&month=January".
    @param queryParameters The input dictionary.
    @return The created parameters string.
    */
    func stringFromQueryParameters(queryParameters : Dictionary<String, String>) -> String {
        var parts: [String] = []
        for (name, value) in queryParameters {
            var part = NSString(format: "%@=%@",
               name.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!,
            value.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!)
            parts.append(part as String)
        }
        return "&".join(parts)
    }

    /**
    Creates a new URL by adding the given query parameters.
    @param URL The input URL.
    @param queryParameters The query parameter dictionary to add.
    @return A new NSURL.
    */
    func NSURLByAppendingQueryParameters(URL : NSURL!, queryParameters : Dictionary<String, String>) -> NSURL {
        let URLString : NSString = NSString(format: "%@?%@", URL.absoluteString!, self.stringFromQueryParameters(queryParameters))
       return NSURL(string: URLString as String)!
    }
}

let requestController = MyRequestController()
requestController.sendRequest()

希望这有帮助