c# - 检查 XElement(Record) 是否存在？

Question

如何检查 XElement 是否具有 Record 和 INVID 属性？我的函数只返回单个 XElement。即，

<INVENTORY>
  <Record>
    <INVID>1315</INVID>
    <INVNAME>TEST LOCATIONTEST</INVNAME>
    <HOSPNAME>TEST LOCATION</HOSPNAME>
    <INVTYPE>CLINICAL</INVTYPE>
    <INVDT>2013-09-30T09:30:00</INVDT>
    <INVDEF>YES</INVDEF>
    <INVACT>YES</INVACT>
    <UPDDTTM />
    <UPDUSR />
    <ENBREF>true</ENBREF>
    <INVPWD>101315</INVPWD>
  </Record>
</INVENTORY>


XElement xInventory = GetDefaultInventory();        
bool hasInventory = xInventory.Elements("INVID").Any();  //What to do here ? 

if (hasInventory)
{  
    //TO DO Some action 
}

Answer 1

如果你想检查 inventory 元素是否有 Record 元素和 INVID 子元素，那么你可以使用 XPath:

XElement inventory = GetDefaultInventory();
XElement invid = inventory.XPathSelectElement("Record/INVID");
if (invid == null) 
    // not exist

或者 LINQ 方式:

bool exists = inventory.Elements("Record").Elements("INVID").Any();