混淆我的Xpath表达式应该是什么？

Question

我的categories.xml文件如下所示

<categories>
  <root name="Cars -Vehicles" id="CV"></root>
  <root name="Personals" id="PER"></root>
  <root name="Real Estate" id="RE"></root>
  <root name="Property For Rent" id="PFR"></root>
  <root name="Community" id="COM"></root>
</categories>

和我的attibutes.xml文件如下

<attributes>

  <attribute value="ethnicity=ethnicity_african_american" name ="American Indian" categoryid="PER"/>
  <attribute value="ethnicity=ethnicity_asian_pacific_islander" name ="Asian - Pacific Islander" categoryid="PER"/>
  <attribute value="ethnicity=ethnicity_caucasian" name ="Caucasian" categoryid="PER"/>


  <attribute value="amenities=amenities_ac" name ="AC" categoryid="RE, PFR"/>
  <attribute value="amenities=amenities_alarm" name ="Alarm" categoryid="RE, PFR"/>

</attributes>

我限制了我attributeDropdown的选择categoriesDropDown.代码如下

 protected void ddCategories_SelectedIndexChanged(object sender, EventArgs e)
 {
            XmlDataSource xd = new XmlDataSource();
            xd.DataFile = Server.MapPath("Xmls") + "\\attributes.xml";
            xd.XPath = "/attributes/attribute[@categoryid='" + 
                        categoriesDropDown.SelectedValue.ToString() + "']";

            attributeDropdown.DataSource = xd;
            attributeDropdown.DataTextField = "name";
            attributeDropdown.DataValueField = "value";

            attributeDropdown.DataBind();

         // categoriesDropDown.DataTextField = "name";
         // categoriesDropDown.DataValueField = "id";

 }

现在的问题是两个名为AC和Alarm的属性分为房地产和房产出租两类.如何在选择这些类别时绑定这些属性？

如果属性属于多个类别,请说明我的Xpath表达式应该是什么？

Answer 1

也许这不是一个好的解决方案，但您可以使用contains函数，例如：

/attributes/attribute[contains(@categoryid, 'category')]

根据你的代码：

xd.XPath = string.Format("/attributes/attribute[contains(@categoryid, '{0}')]",
    categoriesDropDown.SelectedValue);