使用 Alamofire 网络请求设置body为json

let urlString = "  "
        let json = "{\"offset\":0,\"limit\":5}"
        let url = URL(string: urlString)!
        let jsonData = json.data(using: .utf8, allowLossyConversion: false)!

        var request = URLRequest(url: url)
        request.httpMethod = HTTPMethod.post.rawValue
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.httpBody = jsonData

        Alamofire.request(request).responseJSON {
            (response) in

            if response.result.isSuccess {
                let json = JSON(response.data!)
                print(json)

            } else {

            }
        }