如何将一个XML文件“包含”到另一个XML文件中?

I have a XML schema like:

我有一个XML模式:

<?xml version="1.0" encoding="utf-8"?>
<xs:schema id="MySchema"
    targetNamespace="https://tempuri.org/MySchema.xsd"
    elementFormDefault="qualified"
    xmlns="https://tempuri.org/MySchema.xsd"
    xmlns:mstns="https://tempuri.org/MySchema.xsd"
    xmlns:xs="https://www.w3.org/2001/XMLSchema">
  <xs:element name="MyDocument">
    <xs:complexType>
      <xs:all>
        <xs:element name="TextHeader" type="xs:string" minOccurs="0" />
        <xs:element name="TextBody" type="xs:string" minOccurs="0" />
      </xs:all>
    </xs:complexType>
  </xs:element>
</xs:schema>
<?xml