检查xml节点是否不存在并执行某些操作而不是失败

Given the following XML.

给出以下XML。

<?xml version="1.0" encoding="UTF-8"?>
<xmldata>
   <Products>
       <ProductCode>M406789</ProductCode>
       <ProductID>858</ProductID>
       <ProductName>M406789 Ignition Box</ProductName>
       <ProductDescriptionShort>&lt;img alt="" src="/v/vspfiles/assets/images/alliance_small.jpg" align="right" /&gt;Ignition Box</ProductDescriptionShort>
       <ListPrice>134.2200</ListPrice>
       <ProductPrice>80.5300</ProductPrice>
       <SalePrice>59.9500</SalePrice>
   </Products>
</xmldata>
<?xml ve