Swift从URLSession返回数据 [英] Swift return data from URLSession

问题描述

我无法从HTTPrequest返回数据，也无法使完成处理程序工作。所以请帮助我解决这个问题：

I cannot return data from my HTTPrequest and I can't get completion handlers to work either. So please assist me in my quest to solve this issue:

public static func createRequest(qMes: message, location: String, method: String) -> String{
    let requestURL = URL(string: location)
    var request = URLRequest(url: requestURL!)

    request.httpMethod = method
    request.httpBody = qMes.toString().data(using: .utf8)

    let requestTask = URLSession.shared.dataTask(with: request) {
        (data: Data?, response: URLResponse?, error: Error?) in

        if(error != nil) {
            print("Error: \(error)")
        }

        return String(data: data!, encoding: String.Encoding.utf8) as String!
    }
    requestTask.resume()
}

它是在void函数中检测非void返回语句。此时我很无能......

It is excpecting non-void return statement in void function. At this point I'm clueless...

推荐答案

您可以使用此完成块方法发送最终响应：

You can use this completion block method to send the final response:

对于实例：
我在完成块中返回了String，成功响应后没有错误只是在块中传递结果。

For Instance: I have returned String in completion block, after successful response without error just pass the result in block.

  public func createRequest(qMes: String, location: String, method: String , completionBlock: @escaping (String) -> Void) -> Void
    {

        let requestURL = URL(string: location)
        var request = URLRequest(url: requestURL!)

        request.httpMethod = method
        request.httpBody = qMes.data(using: .utf8)

        let requestTask = URLSession.shared.dataTask(with: request) {
            (data: Data?, response: URLResponse?, error: Error?) in

            if(error != nil) {
                print("Error: \(error)")
            }else
            {

                let outputStr  = String(data: data!, encoding: String.Encoding.utf8) as String!
                //send this block to required place
                completionBlock(outputStr!);
            }
        }
        requestTask.resume()
    } 

您可以使用以下代码执行上述完成功能块：

You can use this below code to execute the above completion block function:

 self.createRequest(qMes: "", location: "", method: "") { (output) in

        }

这将解决您的以下要求。

This will solve your following requirement.

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