C#创建有前缀命名空间的元素和属性

要求创建如

….

XmlDocument docuemnt = new XmlDocument();
XmlElement output = docuemnt.CreateElement(“Output”);
XmlElement row = docuemnt.CreateElement(“Row”);
row.SetAttribute(“nil”, “http://www.w3.org/2001/XMLSchema”, “true”);
output.AppendChild(row);
docuemnt.AppendChild(output);

XmlWriter writer = XmlWriter.Create(Console.Out);
docuemnt.WriteTo(writer);
writer.Flush();
Console.ReadKey();

创建的XML形如

缺点是nil的前缀不是自定义的。我需要前缀是xs。

XmlDocument docuemnt = new XmlDocument();
XmlElement output = docuemnt.CreateElement(“Output”);
XmlElement row = docuemnt.CreateElement(“Row”);
XmlAttribute nil = docuemnt.CreateAttribute(“xs”, “nil”, “http://www.w3.org/2001/XMLSchema”);
nil.Value = “true”;
row.SetAttributeNode(nil);
output.AppendChild(row);
docuemnt.AppendChild(output);

XmlWriter writer = XmlWriter.Create(Console.Out,new XmlWriterSettings { Indent=true});
docuemnt.WriteTo(writer);
writer.Flush();
Console.ReadKey();

创建的XML形如

可是我想把 xmlns:xs=”http://www.w3.org/2001/XMLSchema”移动到Output元素。

方法是直接用SetAttribute方法写出XML命名空间。我本来以为会有专门的方法，或使用XmlNamespace类。
XmlDocument docuemnt = new XmlDocument();
XmlElement output = docuemnt.CreateElement(“Output”);
output.SetAttribute(“xmlns:xs”, “http://www.w3.org/2001/XMLSchema”);
XmlElement row = docuemnt.CreateElement(“Row”);
XmlAttribute nil = docuemnt.CreateAttribute(“xs”, “nil”, “http://www.w3.org/2001/XMLSchema”);
nil.Value = “true”;
row.SetAttributeNode(nil);
//row.SetAttribute(“nil”, “http://www.w3.org/2001/XMLSchema”, “true”);
output.AppendChild(row);
docuemnt.AppendChild(output);

XmlWriter writer = XmlWriter.Create(Console.Out,new XmlWriterSettings { Indent=true});
docuemnt.WriteTo(writer);
writer.Flush();
Console.ReadKey();