xml - 当 XML 位于特定命名空间时如何将 XML 读入 DataTable

Question

我想将一些 XML 数据读入 DataTable - 像这样使用 ReadXml 方法

        var dataTable = new DataTable();
        XmlReader xmlReader = XmlReader.Create(new StringReader(xmlString));
        dataTable.ReadXml(xmlReader);

请参阅下面的 XML 字符串。 XML 包括架构定义，当数据没有命名空间(即在全局命名空间中)时，一切都很好，但我不知道如何指定架构和 XML，以便 XML 数据元素位于另一个命名空间中。

我遇到的异常是“DataTable 'cd:Motorcycles' 与源中的任何 DataTable 都不匹配。”

我知道我犯了一些非常愚蠢的小学生错误，但我现在已经拉扯了一个小时左右的时间 - 摆弄但没有成功。

有人能把我从痛苦中解救出来吗？

有效的 XML

          <NewDataSet xmlns="">
            <xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
              <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:MainDataTable="Motorcycles" msdata:UseCurrentLocale="true">
                <xs:complexType>
                  <xs:choice minOccurs="0" maxOccurs="unbounded">
                    <xs:element name="Motorcycles">
                      <xs:complexType>
                        <xs:sequence>
                          <xs:element name="Manufacturer" type="xs:string" minOccurs="0" />
                          <xs:element name="PercentageOfRiders" type="xs:int" minOccurs="0" />
                        </xs:sequence>
                      </xs:complexType>
                    </xs:element>
                  </xs:choice>
                </xs:complexType>
              </xs:element>
            </xs:schema>
            <Motorcycles>
              <Manufacturer>Honda</Manufacturer>
              <PercentageOfRiders>23</PercentageOfRiders>
            </Motorcycles>
            <Motorcycles>
              <Manufacturer>Yamaha</Manufacturer>
              <PercentageOfRiders>15</PercentageOfRiders>
            </Motorcycles>
            <Motorcycles>
              <Manufacturer>Suzuki</Manufacturer>
              <PercentageOfRiders>16</PercentageOfRiders>
            </Motorcycles>
            <Motorcycles>
              <Manufacturer>BMW</Manufacturer>
              <PercentageOfRiders>6</PercentageOfRiders>
            </Motorcycles>
            <Motorcycles>
              <Manufacturer>Other</Manufacturer>
              <PercentageOfRiders>40</PercentageOfRiders>
            </Motorcycles>
          </NewDataSet>

带有命名空间的 XML(不起作用)

          <cd:NewDataSet xmlns="urn:ChartData" xmlns:cd="urn:ChartData">
            <xs:schema id="NewDataSet" 
                       targetNamespace="urn:ChartData" 
                       xmlns:xs="http://www.w3.org/2001/XMLSchema" 
                       xmlns:msdata="urn:schemas-microsoft-com:xml-msdata"
                       elementFormDefault="qualified">
              <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:MainDataTable="cd:Motorcycles" msdata:UseCurrentLocale="true">
                <xs:complexType>
                  <xs:choice minOccurs="0" maxOccurs="unbounded">
                    <xs:element name="Motorcycles">
                      <xs:complexType>
                        <xs:sequence>
                          <xs:element name="Manufacturer" type="xs:string" minOccurs="0" />
                          <xs:element name="PercentageOfRiders" type="xs:int" minOccurs="0" />
                        </xs:sequence>
                      </xs:complexType>
                    </xs:element>
                  </xs:choice>
                </xs:complexType>
              </xs:element>
            </xs:schema>
            <cd:Motorcycles>
              <cd:Manufacturer>Honda</cd:Manufacturer>
              <cd:PercentageOfRiders>23</cd:PercentageOfRiders>
            </cd:Motorcycles>
            <cd:Motorcycles>
              <cd:Manufacturer>Yamaha</cd:Manufacturer>
              <cd:PercentageOfRiders>15</cd:PercentageOfRiders>
            </cd:Motorcycles>
            <cd:Motorcycles>
              <cd:Manufacturer>Suzuki</cd:Manufacturer>
              <cd:PercentageOfRiders>16</cd:PercentageOfRiders>
            </cd:Motorcycles>
            <cd:Motorcycles>
              <cd:Manufacturer>BMW</cd:Manufacturer>
              <cd:PercentageOfRiders>6</cd:PercentageOfRiders>
            </cd:Motorcycles>
            <cd:Motorcycles>
              <cd:Manufacturer>Other</cd:Manufacturer>
              <cd:PercentageOfRiders>40</cd:PercentageOfRiders>
            </cd:Motorcycles>
          </cd:NewDataSet>

Answer 1

阅读此 XML 时需要考虑两件事:

• XML 命名空间 urn:ChartData

• 数据集中主数据表的名称 - 您可以在此处找到它:

  <xs:element name="NewDataSet" msdata:IsDataSet="true" 
              msdata:MainDataTable="cd:Motorcycles"  <== this name here is important
              msdata:UseCurrentLocale="true">
  

考虑到这两点，您需要更改实例化 DataTable 的方式，然后读取工作正常:

// define the data table's name to be the value of the msdata:MainDataTable 
// attribute on the NewDataSet element, and define the XML namespace to use
DataTable dataTable = new DataTable("Motorcycles", "urn:ChartData");

XmlReader xmlReader = XmlReader.Create(new StringReader(xmlString));
dataTable.ReadXml(xmlReader);

现在，您的 dataTable 应该在其 .Rows 属性中包含一些条目 - 在我的例子中是五个(使用您的第二个示例 XML)。