如何通过Swift使用multipart/form-date将文件发送到服务器

   let boundary = generateBoundary()

   request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")

   let body = createBody(with: fileURL, boundary: boundary)

   request.httpBody = body

   let task = URLSession.shared.dataTask(with: request) { (data, response, error) in

       DispatchQueue.main.async {

           completion(error)

       }

   }

   task.resume()

   if let fileData = try? Data(contentsOf: fileURL) {

       let fileName = fileURL.lastPathComponent

       let mimeType = mimeTypeForFileURL(fileURL)

       body.append("--\(boundary)\r\n".data(using: .utf8)!)

       body.append("Content-Disposition: form-data; name=\"file\"; filename=\"\(fileName)\"\r\n".data(using: .utf8)!)

       body.append("Content-Type: \(mimeType)\r\n\r\n".data(using: .utf8)!)

       body.append(fileData)

       body.append("\r\n".data(using: .utf8)!)

   }

   body.append("--\(boundary)--\r\n".data(using: .utf8)!)

   return body

   if let uti = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, pathExtension as CFString, nil)?.takeRetainedValue(),

       let mimeType = UTTypeCopyPreferredTagWithClass(uti, kUTTagClassMIMEType)?.takeRetainedValue() {

       return mimeType as String

   }

   return "application/octet-stream"

   if let error = error {

       print("Error uploading file: \(error)")

   } else {

       print("File uploaded successfully")

   }