如何在 C# 中使用 XDocument 在根元素中生成具有多个命名空间的 XML 文件？

Question

我想在 C# 中使用 XDocument 为 Outlook 加载项生成自定义 manifest.xml 文件。

我当前的 XML 文件（我现在要生成的文件）如下所示：

<?xml version="1.0" encoding="UTF-8"?>
<OfficeApp xmlns="http://schemas.microsoft.com/office/appforoffice/1.1"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:bt="http://schemas.microsoft.com/office/officeappbasictypes/1.0"
           xmlns:mailappor="http://schemas.microsoft.com/office/mailappversionoverrides"
           xsi:type="MailApp">
  <Id>{0026EAB0-AFBA-43FE-A3FA-C479B6FEECCA}</Id>
  <Version>2.0.0.0</Version>
  <!-- More elements -->
</OfficeApp>

我的主要问题是，我无法向 OfficeApp 元素添加多个命名空间。

我已经尝试了以下方法：

private readonly XNamespace Xsi = "xsi:";
private readonly XNamespace MicrosoftSchemasAppsForOffice = "http://schemas.microsoft.com/office/appforoffice/1.1";
private readonly XNamespace W3 = "http://www.w3.org/2001/XMLSchema-instance";
private readonly XNamespace MicrosoftSchemasOfficeBasicTypes = "http://schemas.microsoft.com/office/officeappbasictypes/1.0";
private readonly XNamespace MicrosoftSchemasMailAppVersion = "http://schemas.microsoft.com/office/mailappversionoverrides";

private XDocument GenerateDocument()
{
    return new XDocument(
      new XDeclaration("1.0", "utf-8", null),
      new XElement("OfficeApp",
        new XAttribute("xmlns", MicrosoftSchemasAppsForOffice),
        new XAttribute(XNamespace.Xmlns + "xsi", W3),
        new XAttribute(XNamespace.Xmlns + "bt", MicrosoftSchemasOfficeBasicTypes),
        new XAttribute(XNamespace.Xmlns + "mailappor", MicrosoftSchemasMailAppVersion),
        new XAttribute(Xsi + "type", "MailApp"),
        new XElement("Id", "{" + Guid.NewGuid().ToString() + "}"),
        new XElement("Version", "2.0.0.0")
      )
    );
}

这导致了以下异常：

System.Xml.XmlException: 'The prefix '' cannot be redefined from '' to    'http://schemas.microsoft.com/office/appforoffice/1.1' within the same start element tag.'

我也尝试更换线

new XAttribute("xmlns", MicrosoftSchemasAppsForOffice),

和

new XAttribute(XNamespace.Xmlns.NamespaceName, MicrosoftSchemasAppsForOffice),

但这给了我以下异常：

System.Xml.XmlException: 'The ':' character, hexadecimal value 0x3A, cannot be included in a name.'

经过数小时的尝试和失败，我仍然不知道如何正确处理 xmlns-namespace。 我究竟做错了什么？ 我认为我试图生成的 XML 代码是有效的，因为它工作得很好。

我很感激任何提示。 谢谢！

Answer 1

您的根命名空间不必作为属性添加，只需用作元素的命名空间。 此外，您必须将 xsi 命名空间值与 type 属性一起使用：

private readonly XNamespace MicrosoftSchemasAppsForOffice = "http://schemas.microsoft.com/office/appforoffice/1.1";
private readonly XNamespace W3 = "http://www.w3.org/2001/XMLSchema-instance";
private readonly XNamespace MicrosoftSchemasOfficeBasicTypes = "http://schemas.microsoft.com/office/officeappbasictypes/1.0";
private readonly XNamespace MicrosoftSchemasMailAppVersion = "http://schemas.microsoft.com/office/mailappversionoverrides";

private XDocument GenerateDocument()
{
    return new XDocument(
      new XDeclaration("1.0", "utf-8", null),
      new XElement(MicrosoftSchemasAppsForOffice + "OfficeApp",
        new XAttribute(XNamespace.Xmlns + "xsi", W3),
        new XAttribute(XNamespace.Xmlns + "bt", MicrosoftSchemasOfficeBasicTypes),
        new XAttribute(XNamespace.Xmlns + "mailappor", MicrosoftSchemasMailAppVersion),
        new XAttribute(W3 + "type", "MailApp"),
        new XElement(MicrosoftSchemasAppsForOffice + "Id", "{" + Guid.NewGuid().ToString() + "}"),
        new XElement(MicrosoftSchemasAppsForOffice + "Version", "2.0.0.0")
      )
    );
}

Answer 2

尝试在 XDocument 中正确获取命名空间是很困难的，所以我通常只解析一个字符串

            string xml = 
                "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" +
                "<OfficeApp xmlns=\"http://schemas.microsoft.com/office/appforoffice/1.1\"" +
                   " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"" +
                   " xmlns:bt=\"http://schemas.microsoft.com/office/officeappbasictypes/1.0\"" +
                   " xmlns:mailappor=\"http://schemas.microsoft.com/office/mailappversionoverrides\"" +
                   " xsi:type=\"MailApp\">" +
                "</OfficeApp>";

            XDocument doc = XDocument.Parse(xml);
            XElement officeApp = doc.Root;
            XNamespace ns = officeApp.GetDefaultNamespace();
            officeApp.Add(new XElement(ns + "Id","{0026EAB0-AFBA-43FE-A3FA-C479B6FEECCA}"));
            officeApp.Add(new XElement(ns + "Version","2.0.0.0"));