Question

我正在使用ObjectContent来构建XML请求，如下所示：

private HttpRequestMessage CreateRequest<T>(T content, HttpMethod method) where T : class
{
    // create http message request
    var request = CreateRequest(method);

    // set contents of the HTTP message
    var xmlFormatter = new XmlMediaTypeFormatter
                           {
                               Indent = true,
                               UseXmlSerializer = true
                           };

    var objectContent = new ObjectContent<T>(content, xmlFormatter);
    request.Content = objectContent;

    // return HttpRequestMessage
    return request;
}

这很好用！但是，输出不包括XML前导码，例如

<?xml version="1.0" encoding="UTF-8"?>

如何鼓励XmlSerializer加入该行？

Answer 1

我无法弄清楚如何使用ObjectContent执行此操作，因此我先将其序列化，然后通过StreamContent将其传递给请求：

private HttpRequestMessage CreateRequest<T>(T content, HttpMethod method) where T : class
{
    var request = CreateRequest(method);
    var encoding = Encoding.UTF8;
    var xmlWriterSettings = new XmlWriterSettings { Indent = true, Encoding = encoding };

    // StringWriterWithEncoding courtesy of http://stackoverflow.com/a/9459212/29
    using (var stringWriter = new StringWriterWithEncoding(encoding))
    using (var xmlWriter = XmlWriter.Create(stringWriter, xmlWriterSettings))
    {
        var xmlSerializer = new XmlSerializer(typeof(T));
        xmlSerializer.Serialize(xmlWriter, content);
        request.Content = new StringContent(stringWriter.ToString(), encoding);
    }

    return request;
}

Answer 2

你的旧解决方案非常接近，做得不错。

可以在覆盖类中的设置上更改OmitXmlDeclaration，如此

    public class CustomXmlMediaTypeFormatter : XmlMediaTypeFormatter
    {
        public CustomXmlMediaTypeFormatter()
        {
            UseXmlSerializer = true;
            WriterSettings.OmitXmlDeclaration = false;
        }
    }

我花了一段时间才弄明白，但是人们应该知道，只要将WriterSettings设置为不省略序言就可以了。

如何在我的请求XML中包含序言？

2 个答案: