import MobileCoreServices


func createRequest(userid: String, image: [UIImage]) throws -> NSMutableURLRequest {

   var parameters: [String : AnyObject] = [
       "userid": userid,
       "Image1": image[0],  // You need to set the UIImage Type image parameters 
       "Image2": image[1],   
       "Image3": image[2],
       "Image4": image[3]
   ]

    print(parameters)

    let boundary = generateBoundaryString()

    let url = URL(string: Your URL String)!
    let request = NSMutableURLRequest(url: url)
    request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")

    request.httpBody = try createBody(with: parameters as [String : AnyObject], boundary: boundary)

    return request
}

以下是multipart / form-data中的上传图像和参数代码

Here is Code of Upload Image and Parameters in multipart/form-data

func createBody(with parameters: [String: AnyObject], boundary: String) throws -> Data {

    var body = Data()

    for (key, value) in parameters {

        if(value is String || value is NSString) {
            body.append("--\(boundary)\r\n")
            body.append("Content-Disposition: form-data; name=\"\(key)\"\r\n\r\n")
            body.append("\(value)\r\n")
        }else if(value is UIImage) {
            let r = arc4random()
            let filename = "image\(r).jpg"
            let data = UIImageJPEGRepresentation(value as! UIImage,1);
            let mimetype = mimeTypeForPath(path: filename)

            body.append("--\(boundary)\r\n")
            body.append("Content-Disposition: form-data; name=\"\(key)\"; filename=\"\(filename)\"\r\n")
            body.append("Content-Type: \(mimetype)\r\n\r\n")
            body.append(data!)
            body.append("\r\n")
        }

    }

    body.append("--\(boundary)--\r\n")

    return body

}

func mimeTypeForPath(path: String) -> String {
    let pathExtension = path.pathExtension
    var stringMimeType = "application/octet-stream";
    if let uti = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, pathExtension as! CFString, nil)?.takeRetainedValue() {
        if let mimetype = UTTypeCopyPreferredTagWithClass(uti, kUTTagClassMIMEType)?.takeRetainedValue() {
            stringMimeType = mimetype as NSString as String
        }
    }
    return stringMimeType;
}

extension String {
   var ns: NSString {
       return self as NSString
   }
   var pathExtension: String? {
       return ns.pathExtension
   }
   var lastPathComponent: String? {
       return ns.lastPathComponent
   }
}