XDocument XDeclaration 未出现在 ToString 结果中

Question

我正在尝试形成一个 XML 文档，我将使用它通过 HTTPS 发送到 API，但是我注意到，即使我已经添加了一个 XDeclaration 元素到我的XML XDeclaration 没有出现在我 return 使用 xmlDoc.ToString() 方法的字符串中。

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

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();
                }
            }
        }

注意：xmlDoc.ToString() 值作为第一个参数传递给 SendRequest()，requestContentType 被设置为 "text/xml"

Answer 1

序列化为字符串无法保留 Utf-8 声明，因为它在那时将无效 - 因此它将被删除。

如果您需要Utf-8（默认）编码，您需要将数据保存到流中。示例和更多讨论 - Serializing an object as UTF-8 XML in .NET.

Answer 2

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"，请参阅此处：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。

XDocument XDeclaration 未出现在 ToString 结果中

XDocument XDeclaration not appearing in ToString result

.net

c#

xml

linq-to-xml