使用alamofire的multipart/form-data

Question

我正在进行.post API调用，我需要使用multipart/form-data。我知道如何使用JSON进行调用，但我不熟悉multipart/form-data。使用JSON，这是一个超级简单的调用。只要创建一个类型参数：

var parameters:Parameters = [:] 
parameters["username"] = emailTextField.text! 
parameters["password"] = passwordTextField.text! 

Alamofire.request(url, method: .post, parameters: parameters, encoding: JSONEncoding.default, headers: headers).responseJSON { (response) in 
    //Code here 
} 

我们如何写这个使用表单数据。什么是最简单的方法来做到这一点？我不需要上传任何文件或任何东西。我所能做的就是用极其简单的物品打电话。使用表单数据做到这一点的最简洁的方法是什么？我确信这是一个非常基本的问题，我四处寻找堆栈溢出的帮助，但我只看到它用于更高级的文件调用。我只想知道如何以最简单的方式做到这一点，因为它本质上代替了JSON调用。从文档

Answer 1

例子：

Alamofire.upload(
    multipartFormData: { multipartFormData in 
     multipartFormData.append(unicornImageURL, withName: "unicorn") 
     multipartFormData.append(rainbowImageURL, withName: "rainbow") 
    }, 
    to: "https://httpbin.org/post", 
    encodingCompletion: { encodingResult in 
     switch encodingResult { 
     case .success(let upload, _, _): 
      upload.responseJSON { response in 
       debugPrint(response) 
      } 
     case .failure(let encodingError): 
      print(encodingError) 
     } 
    } 
) 

方法的完整描述（如果你需要设置页眉Source）：

/// Encodes `multipartFormData` using `encodingMemoryThreshold` with the default `SessionManager` and calls 
/// `encodingCompletion` with new `UploadRequest` using the `url`, `method` and `headers`. 
/// 
/// It is important to understand the memory implications of uploading `MultipartFormData`. If the cummulative 
/// payload is small, encoding the data in-memory and directly uploading to a server is the by far the most 
/// efficient approach. However, if the payload is too large, encoding the data in-memory could cause your app to 
/// be terminated. Larger payloads must first be written to disk using input and output streams to keep the memory 
/// footprint low, then the data can be uploaded as a stream from the resulting file. Streaming from disk MUST be 
/// used for larger payloads such as video content. 
/// 
/// The `encodingMemoryThreshold` parameter allows Alamofire to automatically determine whether to encode in-memory 
/// or stream from disk. If the content length of the `MultipartFormData` is below the `encodingMemoryThreshold`, 
/// encoding takes place in-memory. If the content length exceeds the threshold, the data is streamed to disk 
/// during the encoding process. Then the result is uploaded as data or as a stream depending on which encoding 
/// technique was used. 
/// 
/// - parameter multipartFormData:  The closure used to append body parts to the `MultipartFormData`. 
/// - parameter encodingMemoryThreshold: The encoding memory threshold in bytes. 
///          `multipartFormDataEncodingMemoryThreshold` by default. 
/// - parameter url:      The URL. 
/// - parameter method:     The HTTP method. `.post` by default. 
/// - parameter headers:     The HTTP headers. `nil` by default. 
/// - parameter encodingCompletion:  The closure called when the `MultipartFormData` encoding is complete. 
public func upload(
    multipartFormData: @escaping (MultipartFormData) -> Void, 
    usingThreshold encodingMemoryThreshold: UInt64 = SessionManager.multipartFormDataEncodingMemoryThreshold, 
    to url: URLConvertible, 
    method: HTTPMethod = .post, 
    headers: HTTPHeaders? = nil, 
    encodingCompletion: ((SessionManager.MultipartFormDataEncodingResult) -> Void)?)