how to populate the tables within xmlDataDocument.DataSet

Question

Hi all:

I am working on a C# application that involves using XML schema file as databases for message definitions and XML file as databases for message data.

I was following the example I found:http://msdn.microsoft.com/en-us/library/system.xml.xmldatadocument.dataset%28v=VS.100%29.aspx

I wrote my own xsd and XML file. I used the same approach in the example, read the xsd file and then load the xml file. But I don't have any "Rows" created for my DataTable. I used debugger to step through my codes. When I am get my DataTable use xmlDataDocument.DataSet.Tables["name of the table"], the Rows property of that tables is 0.

Does anybody know what might cause the DataSet tables not get populated after I loaded the xmlDataDocument with XML file?

Here is a fragment of XSD file:

<?xml version="1.0" encoding="utf-8"?>
<xs:schema id="test"
    targetNamespace="http://tempuri.org/test.xsd"
      elementFormDefault="qualified"
    xmlns="http://tempuri.org/test.xsd"
    xmlns:mstns="http://tempuri.org/test.xsd"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
>

<xs:element name="reboot_msg">
    <xs:complexType>
      <xs:complexContent>
        <xs:extension base="header_s">
          <xs:sequence>

           <xs:element name="que_name">
            <xs:simpleType>
             <xs:restriction base="xs:string">
              <xs:minLength value="4"/>
               <xs:maxLength value="8"/>
              </xs:restriction>
             </xs:simpleType>
            </xs:element>

        <xs:element name="priority" type="xs:unsignedShort"/>

          </xs:sequence>
        </xs:extension>
      </xs:complexContent>
    </xs:complexType>
  </xs:element>

and here is a fragment of the XML file:

<?xml version="1.0" standalone="yes"?>
<test xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >

  <reboot_msg>
    <message_length>16</message_length>
    <message_type>7</message_type>
    <message_sequence>0</message_sequence>
    <que_name>NONE</que_name>
    <priority>5</priority>
  </reboot_msg>

It could be the XML and XSD file I created missed something. Please help.

Thanks

Answer 1

To use an XML Schema with XmlDataDocument, you should only create the schema in the DataSet Designer. XmlDataDocument, and DataSet in general, can only handle a subset of XML Schema. To ensure that your schema only uses that subset, you should create it using the DataSet Designer.