所以我是愚蠢的。主要的事情是我错过了设置消息的主体到SOAP请求。我的更新更正代码如下：

//
//  ViewController.swift
//  TestWebServiceSoap
//
//  Created by George M. Ceaser Jr on 6/2/15.
//  Copyright (c) 2015 George M. Ceaser Jr. All rights reserved.
//

import UIKit

class ViewController: UIViewController {
var is_SoapMessage: String = "<soapenv:Envelope xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:cgs=\"http://www.cgsapi.com/\"><soapenv:Header/><soapenv:Body><cgs:GetSystemStatus/></soapenv:Body></soapenv:Envelope>"

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

@IBAction func btnClicked(sender: AnyObject)
{
    var is_URL: String = "http://www.cgsapi.com/CGSWebService.asmx"

    var lobj_Request = NSMutableURLRequest(URL: NSURL(string: is_URL)!)
    var session = NSURLSession.sharedSession()
    var err: NSError?

    lobj_Request.HTTPMethod = "POST"
    lobj_Request.HTTPBody = is_SoapMessage.dataUsingEncoding(NSUTF8StringEncoding)
    lobj_Request.addValue("www.cgsapi.com", forHTTPHeaderField: "Host")
    lobj_Request.addValue("text/xml; charset=utf-8", forHTTPHeaderField: "Content-Type")
    lobj_Request.addValue(String(count(is_SoapMessage)), forHTTPHeaderField: "Content-Length")
    //lobj_Request.addValue("223", forHTTPHeaderField: "Content-Length")
    lobj_Request.addValue("http://www.cgsapi.com/GetSystemStatus", forHTTPHeaderField: "SOAPAction")

    var task = session.dataTaskWithRequest(lobj_Request, completionHandler: {data, response, error -> Void in
        println("Response: \(response)")
        var strData = NSString(data: data, encoding: NSUTF8StringEncoding)
        println("Body: \(strData)")

        if error != nil
        {
            println("Error: " + error.description)
        }

    })
    task.resume()
}

}

Swift 5.2，XCode 12

我或多或少遵循了乔治在自我回复中所做的方法。我认为留下一个最新的Swift和Xcode代码样本可能对一些人有帮助：

private func exampleSoapRequest() {
    let url = URL(string: ProvidedData.urlString)!
    let request = NSMutableURLRequest(url: url)
    request.httpMethod = "POST"
    request.httpBody = ProvidedData.envelope.data(using: .utf8)
    request.addValue(String(ProvidedData.envelope.count), forHTTPHeaderField: "Content-Length")
    request.addValue("text/xml; charset=utf-8", forHTTPHeaderField: "Content-Type")
    request.addValue("<PUT HERE YOUR SOAP ACTION IF NEEDED>", forHTTPHeaderField: "SOAPAction")

    let task = URLSession.shared
        .dataTask(with: request as URLRequest,
                  completionHandler: { data, response, error in
                    guard error == nil else {
                        // Handle the error
                        print(error)
                    }

                    guard let data = data else {
                        return
                    }
                    // Continue checking response or data...
        })
    task.resume()
}

在ProvidedData中，我假设你会以某种方式传递你的url和信封。
除此之外，如果你想拥有一个更结构化和“基于参数”的信封，并且你不介意使用外部库，@Pulkit Kumar Singh提出的AEXML解决方案也很有趣。

参考这个链接https://github.com/blastar/Swift-SOAP-with-Alamofire。它给你一个更结构化的方法来处理肥皂与Almofire。
1.使用可可pod可以导入以下pod
https://cocoapods.org/了解如何设置可可荚

use_frameworks!

target 'Swift-SOAP-with-Alamofire' do
pod 'Alamofire'
pod 'SWXMLHash'
pod 'AEXML'
pod 'StringExtensionHTML'
end

post_install do |installer|
  installer.pods_project.targets.each do |target|
    target.build_configurations.each do |config|
      config.build_settings['CONFIGURATION_BUILD_DIR'] = '$PODS_CONFIGURATION_BUILD_DIR'
    end
  end
end

2.这只是通过almofire实现soap的一种方法，almofire更有结构化。你必须根据你的实现做一些小的任务来定制

func getCountries(completion: (result: [Country]) -> Void) -> Void {

        var result = [Country]()
        let soapRequest = AEXMLDocument()
        let envelopeAttributes = ["xmlns:SOAP-ENV" : "http://schemas.xmlsoap.org/soap/envelope/", "xmlns:ns1" : "http://www.webserviceX.NET"]
        let envelope = soapRequest.addChild(name: "SOAP-ENV:Envelope", attributes: envelopeAttributes)
        let body = envelope.addChild(name: "SOAP-ENV:Body")
        body.addChild(name: "ns1:GetCountries")

        let soapLenth = String(soapRequest.xmlString.characters.count)
        let theURL = NSURL(string: "http://www.webservicex.net/country.asmx")

        let mutableR = NSMutableURLRequest(URL: theURL!)
        mutableR.addValue("text/xml; charset=utf-8", forHTTPHeaderField: "Content-Type")
        mutableR.addValue("text/html; charset=utf-8", forHTTPHeaderField: "Content-Type")
        mutableR.addValue(soapLenth, forHTTPHeaderField: "Content-Length")
        mutableR.HTTPMethod = "POST"
        mutableR.HTTPBody = soapRequest.xmlString.dataUsingEncoding(NSUTF8StringEncoding)

        Alamofire.request(mutableR)
            .responseString { response in
                if let xmlString = response.result.value {
                    let xml = SWXMLHash.parse(xmlString)
                    let body =  xml["soap:Envelope"]["soap:Body"]
                    if let countriesElement = body["GetCountriesResponse"]["GetCountriesResult"].element {
                        let getCountriesResult = countriesElement.text!
                        let xmlInner = SWXMLHash.parse(getCountriesResult.stringByDecodingHTMLEntities)
                        for element in xmlInner["NewDataSet"]["Table"].all {
                            if let nameElement = element["Name"].element {
                                var countryStruct = Country()
                                countryStruct.name = nameElement.text!
                                result.append(countryStruct)
                            }
                        }
                    }
                    completion(result: result)
                }else{
                    print("error fetching XML")
                }
        }
    }

希望能帮上忙。

您可以使用下面的代码来进行Web服务调用。

let url = NSURL(string: "https://www.google.com/")

        var request:NSMutableURLRequest = NSMutableURLRequest(URL:url!)
        var bodyData = "data=something"
        request.HTTPMethod = "POST"
        request.HTTPBody = bodyData.dataUsingEncoding(NSUTF8StringEncoding);
        NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue())
            {
                (response, data, error) in
                print(response)
                if let HTTPResponse = response as? NSHTTPURLResponse {
                    let statusCode = HTTPResponse.statusCode

                    if statusCode == 200 {
                        // Yes, Do something. 
                    }else{
                         print("Error")
                         }
                }

        }

*api calling for returning data type soap 
 swift 2.2. and above*


let urlForService = NSURL.init(string: "enter your url string")

 let postString = String(format: "TokenId=%@&LoggedUserId=%@&UserDeviceId=%@", arguments: ["parameter value","parameter value","parameter value"])

    do
    {
        let urlSession:NSURLSession = NSURLSession.sharedSession()

        let urlRequest:NSMutableURLRequest = NSMutableURLRequest(URL: urlForService!)

        urlRequest.HTTPShouldHandleCookies = false
        urlRequest.timeoutInterval = 120 ;
        urlRequest.HTTPMethod = "POST";

        urlRequest.addValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
        urlRequest.addValue("\(postString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)?.length)", forHTTPHeaderField: "Content-Length")
        urlRequest.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)

        let session = urlSession.dataTaskWithRequest(urlRequest, completionHandler: { (data, response, errorResponse) in

            if errorResponse != nil {
                print(errorResponse!.localizedDescription)
            }
            else
            {
                if data != nil
                {
                    do {

                        if let dictionary = try NSJSONSerialization.JSONObjectWithData(data!, options: .MutableContainers) as? NSDictionary {

                            let dateformaterweb = NSDateFormatter()
                            dateformaterweb.dateFormat = "DD/MM/YYYY"
                            let tempwitnohdate = dictionary.valueForKey("AllContact") as! NSArray

                            for i in tempwitnohdate{

                                if String(i.valueForKey("Birthdate")!) != ""{

                                    let name = String(i.valueForKey("ContactName")!)
                                    let number = String(i.valueForKey("ContactNo")!)

                                    let temparray = String(i.valueForKey("Birthdate")!).componentsSeparatedByString("/")
                                    let month = temparray[1]
                                    let day = temparray[0]

                                    let dateweb = ([temparray[0]] + [temparray[1]]).joinWithSeparator(",")
                                    self.usercontact.append(Utility(name: name, number: number, date: dateweb, month:Int(month)!, day:Int(day)!))

                                }
                                else{
                                    let name = String(i.valueForKey("ContactName")!)
                                    let number = String(i.valueForKey("ContactNo")!)
                                    let dateweb = self.formater.stringFromDate(self.date)
                                    self.usercontactsort.append(Utility(name: name, number: number, date:  dateweb, month:13, day:32))

                                }

                            }

                            self.usercontactsort  = self.usercontactsort.sort { $0.strName.localizedStandardCompare($1.strName) == NSComparisonResult.OrderedAscending }

                            self.usercontact.sortInPlace{$0.monthorder < $1.monthorder}
                            for i in 0...self.usercontact.count - 1{

                                for j in i...self.usercontact.count - 1{

                                    if self.usercontact[i].monthorder == self.usercontact[j].monthorder &&  i != j{
                                        if self.usercontact[i].dayorder > self.usercontact[j].dayorder{
                                            let temp = self.usercontact[i]
                                            self.usercontact[i] = self.usercontact[j]
                                            self.usercontact[j] = temp
                                        }
                                    }

                                }
                            }
                            self.finaldata = self.usercontact + self.usercontactsort
                        }
                        self.tableview.reloadData()
                    }
                    catch {
                        print("Error \(error)")
                    }

                }
            }
        })
        session.resume()

    }

- (BOOL)callWebService {
    NSString *soapMessage = @"<soapenv:Envelope xmlns:soapenv=""http://schemas.xmlsoap.org/soap/envelope/"" xmlns:cgs=""http://www.cgsapi.com/""><soapenv:Header/><soapenv:Body><cgs:GetSystemStatus/></soapenv:Body></soapenv:Envelope>";

    // SOAP request settings
    NSURL *url = [NSURL URLWithString:@"http://www.cgsapi.com/CGSWebService.asmx"];

    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    NSURLSession *session = [NSURLSession sharedSession];
    NSError *error;

    request.HTTPMethod = @"POST";
    request.HTTPBody = [soapMessage dataUsingEncoding:NSUTF8StringEncoding];

    [request addValue:@"www.cgsapi.com" forHTTPHeaderField:@"Host"];
    [request addValue:@"text/xml; charset=utf-8" forHTTPHeaderField:@"Content-Type"];
    [request addValue:[NSString stringWithFormat:@"%i", soapMessage.length] forHTTPHeaderField:@"Content-Length"];
    [request addValue:@"http://www.cgsapi.com/GetSystemStatus" forHTTPHeaderField:@"SOAPAction"];

    NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
        NSLog(@"response: %@", response);
        NSString *output = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

        NSLog(@"output: %@", output);
        if (error !=nil) {
            NSLog(@"error: %i %@", error.code, error.description);
        }
    }];

    [task resume];

    return true;
}