如何控制XmlSerializer在何处添加默认名称空间

Question

I'm trying to control at what level the default namespace is added to the output of the XmlSerializer ...

So far I've got ...

<GetAccountDetailRequestStructure>
  <AccountRef xmlns="http://www.govtalk.gov.uk/NAC/GetAccountDetail">4026069</AccountRef>
  <AccountType xmlns="http://www.govtalk.gov.uk/NAC/GetAccountDetail">C</AccountType>
  <SelectionOptions xmlns="http://www.govtalk.gov.uk/NAC/GetAccountDetail">
    <FromDate>2000-01-01</FromDate>
    <ToDate>2015-10-23</ToDate>
    <IncludeAccountSummary>false</IncludeAccountSummary>
  </SelectionOptions>
</GetAccountDetailRequestStructure>

using ...

var ns = new XmlSerializerNamespaces();
ns.Add(string.Empty, "http://www.govtalk.gov.uk/NAC/GetAccountDetail");
var xs = new XmlSerializer(typeof(T));
xs.Serialize(xmlWriter, obj, ns);

but what I'm trying to get is ...

<GetAccountDetailRequestStructure xmlns="http://www.govtalk.gov.uk/NAC/GetAccountDetail">
  <AccountRef>4026069</AccountRef>
  <AccountType>C</AccountType>
  <SelectionOptions>
    <FromDate>2000-01-01</FromDate>
    <ToDate>2015-10-23</ToDate>
    <IncludeAccountSummary>false</IncludeAccountSummary>
  </SelectionOptions>
</GetAccountDetailRequestStructure>

which I believe is an equivalent to the first XML example

Answer 1

Try passing the default namespace to the constructor of XmlSerializer as well:

const string defaultNamespace = "http://www.govtalk.gov.uk/NAC/GetAccountDetail";
var ns = new XmlSerializerNamespaces();
ns.Add(string.Empty, defaultNamespace);

// Note the 2nd constructor argument.
var xs = new XmlSerializer(typeof(T), defaultNamespace);

xs.Serialize(xmlWriter, obj, ns);