假设你试图避免接受什么那里不是短名称...
var persons = from person in xmlDoc.Descendants("Table")
let shortNameElement = person.Element("SHORTNAME")
where shortNameElement != null && shortNameElement.Value.Contains("123")
select new
{
shortName = person.Element("SHORTNAME").Value,
longName = person.Element("LONGNAME").Value,
address = person.Element("ADDRESS").Value,
Phone = person.Element("PHONE") != null ?
person.Element("PHONE").Value : "",
zip = person.Element("ZIPCODE") != null ?
person.Element("ZIPCODE").Value : "",
};
或者,您可以使用空合并运算符,以使所有的这些简单一点:
var emptyElement = new XElement("ignored", "");
var persons = from person in xmlDoc.Descendants("Table")
where (person.Element("SHORTNAME") ?? emptyElement).Value.Contains("123")
select new
{
shortName = person.Element("SHORTNAME").Value,
longName = person.Element("LONGNAME").Value,
address = person.Element("ADDRESS").Value,
Phone = (person.Element("PHONE") ?? emptyElement).Value
zip = (person.Element("ZIPCODE") ?? emptyElement).Value
};
或者,您可以写一个扩展方法:
public static string ValueOrEmpty(this XElement element)
{
return element == null ? "" : element.Value;
}
,然后用它是这样的:
var persons = from person in xmlDoc.Descendants("Table")
where person.Element("SHORTNAME").ValueOrEmpty().Contains("123")
select new
{
shortName = person.Element("SHORTNAME").Value,
longName = person.Element("LONGNAME").Value,
address = person.Element("ADDRESS").Value,
Phone = person.Element("PHONE").ValueOrEmpty(),
zip = person.Element("ZIPCODE").ValueOrEmpty()
};
这是行不通的,因为元素返回的XElement,而不是一个字符串。 – 2009-10-05 11:31:39
我的不好,在我写下它的时刻似乎很简单。 – 2009-10-05 11:36:56