我正在尝试形成一个 XML 文档，我将使用它通过 HTTPS 将其发送到 API，但是我注意到，即使我已将 XDeclaration 元素添加到我的 XML，XDeclaration 也没有出现在字符串中我返回使用 xmlDoc.ToString()方法。

有谁知道我是否缺少特定设置或 <?xml version="1.0" encoding="UTF-8" ?> 的任何原因？元素没有出现？

xmlDoc = new XDocument(
            new XDeclaration("1.0", "UTF-8", "yes"),
            new XElement("NABTransactMessage",
                new XElement("MessageInfo",
                    new XElement("MessageID", "5167813675aa47d181a7c76979f2de00"),
                    new XElement("MessageTimeStamp", "20152701024752898882+000"),
                    new XElement("timeoutValue", 60),
                    new XElement("apiVersion", "spxml-4.2")
                ),
                new XElement("MerchantInfo",
                    new XElement("MerchantID", "XYZ0010"),
                    new XElement("password", "abcd1234")
                ),
                new XElement("RequestType", "Periodic"),
                new XElement("Periodic",
                    new XElement("PeriodicList", new XAttribute("count", 1),
                        new XElement("PeriodicItem", new XAttribute("ID", 1),
                            new XElement("actionType", "addcrn"),
                            new XElement("periodicType", 5),
                            new XElement("crn", "85c2960d-1422326872"),
                            new XElement("CreditCardInfo", 
                                new XElement("cardNumber", 4111111111111111),
                                new XElement("expiryDate", "08/20"),
                                new XElement("cvv", 123)
                            )
                        )
                    )
                )
            )
        );

return xmlDoc.ToString(SaveOptions.None);

通过 HTTPS 发送请求的代码:

    public static string SendRequest(string requestContent, string requestContentType, string requestUrl)
    {
        try
        {
            var request = (HttpWebRequest)WebRequest.Create(requestUrl);
            byte[] bytes;

            bytes = System.Text.Encoding.UTF8.GetBytes(requestContent);

            request.ContentType = requestContentType + "; encoding='utf-8'";
            request.ContentLength = bytes.Length;
            request.Method = "POST";
            //request.Timeout = 5000;

            ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;

            using (var requestStream = request.GetRequestStream())
            {
                requestStream.Write(requestContent, 0, requestContent.Length);
            }

            using (var response = (HttpWebResponse)request.GetResponse())
            {
                using (var responseStream = response.GetResponseStream())
                {
                    return new StreamReader(responseStream).ReadToEnd();
                }
            }
        }

备注:xmlDoc.ToString()值正在传递给 SendRequest()作为第一个参数，requestContentType被设置为 "text/xml"

最佳答案

XDocument.ToString() 不包含声明。相反，使用 XDocument.Save() ，例如:

    public static string ToXml(this XDocument xDoc)
    {
        StringBuilder builder = new StringBuilder();
        using (TextWriter writer = new StringWriter(builder))
        {
            xDoc.Save(writer);
            return builder.ToString();
        }
    }

如果您特别需要将编码字符串设为“UTF-8”，请参见此处:Force XDocument to write to String with UTF-8 encoding

请注意，此扩展适用于 XDocument，而不是具有 OuterXml 的 XmlDocument。

关于c# - XDocument XDeclaration 未出现在 ToString 结果中，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/28183461/