在解析XDocument时处理null XElements

Question

做这样的事情是否有更好的方法:

private XElement GetSafeElem(XElement elem, string key)
{
    XElement safeElem = elem.Element(key);
    return safeElem ?? new XElement(key);
}

private string GetAttributeValue(XAttribute attrib)
{
    return attrib == null ? "N/A" : attrib.Value;
}

var elem = GetSafeElem(elem, "hdhdhddh");
string foo = GetAttributeValue(e.Attribute("fkfkf"));

//attribute now has a fallback value

从XML文档解析元素/属性值时？在某些情况下,在执行以下操作时可能找不到该元素:

string foo (string)elem.Element("fooelement").Attribute("fooattribute").Value

因此会发生对象引用错误(假设未找到元素/属性).尝试访问元素值时相同

Answer 1

我只想使用扩展方法.它是一样的,但它更漂亮:

public static XElement SafeElement(this XElement element, XName name)
{
    return element.Element(name) ?? new XElement(name);
}

public static XAttribute SafeAttribute(this XElement element, XName name)
{
    return element.Attribute(name) ?? new XAttribute(name, string.Empty);
}

然后你可以这样做:

string foo = element.SafeElement("fooelement").SafeAttribute("fooattribute").Value;