ios - Swift 从 URLSession 返回数据

Question

我无法从我的 HTTP 请求返回数据，我也无法让完成处理程序工作。所以请帮助我解决这个问题:

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()
}

在 void 函数中期待非 void return 语句。在这一点上我毫 headless 绪...

Answer 1

您可以使用此完成 block 方法发送最终响应:

例如:我在完成 block 中返回了字符串，成功响应后没有错误，只需将结果传递到 block 中。

  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()
    } 

您可以使用下面的代码来执行上面的完成 block 功能:

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

        }

这将解决您的以下需求。