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我有一个XML文件名称Customerx.xml。它的父标签为。它有很多。为什么在尝试从XML文件中读取数据时会得到Null Referenfe异常?
我的客户类的定义为:在XML
public class Customer
{
private List<Customer> customerList;
public string CustomerID { get; set; }
public string CompanyName { get; set; }
public string Address { get; set; }
public string City { get; set; }
public string Region { get; set; }
public string PostalCode { get; set; }
public string Country { get; set; }
public string Phone { get; set; }
public string Fax { get; set; }
public List<Customer> GetCustomerList()
{
if (customerList == null)
CreateCustomerLists();
return customerList;
}
private void CreateCustomerLists()
{
var list = from e in XDocument.Load("Customers.xml").Root.Elements("customer")
select new Customer
{
CustomerID = (string) e.Element("id"),
CompanyName = (string) e.Element("name"),
Address = (string) e.Element("address"),
City = (string) e.Element("city"),
Region = (string) e.Element("region"),
PostalCode = (string) e.Element("postalcode"),
Country = (string) e.Element("country"),
Phone = (string) e.Element("phone"),
Fax = (string) e.Element("fax"),
};
customerList = list.ToList();
}
}
的数据是:
<?xml version="1.0"?>
<customers>
<customer>
<id>ALFKI</id>
<name>Alfreds Futterkiste</name>
<address>Obere Str. 57</address>
<city>Berlin</city>
<postalcode>12209</postalcode>
<country>Germany</country>
<phone>030-0074321</phone>
<fax>030-0076545</fax>
</customer>
<customer>
<id>ANATR</id>
<name>Ana Trujillo Emparedados y helados</name>
<address>Avda. de la Constitución 2222</address>
<city>México D.F.</city>
<postalcode>05021</postalcode>
<country>Mexico</country>
<phone>(5) 555-4729</phone>
<fax>(5) 555-3745</fax>
</customer>
在CreateCustomerLists()
方法在阅读我得到一个空引用execption来自xlm文件的数据?这是为什么发生?我怎样才能摆脱它?
哪条线?你的XML是什么样的?一个简短的*完整的*程序展示这个问题真的会有帮助... – 2013-05-01 15:12:14
几乎所有'NullReferenceException'的情况都是一样的。请参阅“[什么是.NET中的NullReferenceException?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-in-net)”的一些提示。 – 2013-05-01 15:19:57
@JonSkeet,我编辑了我的问题。现在我也提供了两个xml数据。我得到错误var list = from ...这行在CreateCustomerLists()mehod上。 – Pankouri 2013-05-01 15:20:56