我设法将一个XElement成功链接到我的程序中虽然我没有运气，但我已经尝试使用其他两个;
IEnumerable query =来自doc.Descendants的预订（＆＃34; Booking＆＃34;）
虽然我很幸运将这些值放入列表框中。
以下是功能代码：
private void btnimport_Click(object sender, EventArgs e)
{
OpenFileDialog open = new OpenFileDialog();
open.CheckFileExists = true;
open.InitialDirectory = "@C:\\";
open.Filter = "XML Files (*.xml)|*.xml|All Files(*.*)|*.*";
open.Multiselect = false;
if (open.ShowDialog() == DialogResult.OK)
{
try
{
XDocument doc = XDocument.Load(open.FileName);
//Grabs the customer elements
var query = from booking in doc.Descendants("Booking")
select new
{
//Customer Elements
CustomerId = booking.Element("CustomerId").Value,
Title = booking.Element("Title").Value,
Firstname = booking.Element("FirstName").Value,
Lastname = booking.Element("LastName").Value,
DateofBirth = booking.Element("DateofBirth").Value,
Email = booking.Element("Email").Value,
HouseNo = booking.Element("HouseNo").Value,
Street = booking.Element("Street").Value,
Postcode = booking.Element("Postcode").Value,
Town = booking.Element("Town").Value,
County = booking.Element("County").Value,
ContactNo = booking.Element("ContactNo").Value,
//Holiday Elements
HolidayId = booking.Element("HolidayId").Value,
HotelName = booking.Element("HotelName").Value,
Location = booking.Element("Location").Value,
BookFrom = booking.Element("BookFrom").Value,
BookTo = booking.Element("BookTo").Value,
CheckInTime = booking.Element("CheckInTime").Value,
CheckOutTime = booking.Element("CheckOutTime").Value,
NoOfRoomsBooked = booking.Element("NoOfRoomsBooked").Value,
RoomType = booking.Element("RoomType").Value,
RoomServices = booking.Element("RoomServices").Value,
Parking = booking.Element("Parking").Value,
Pet = booking.Element("Pet").Value,
//TravelInfo Elements
TravelInfoId = booking.Element("TravelInfoId").Value,
TravellingFrom = booking.Element("TravellingFrom").Value,
Destination = booking.Element("Destination").Value,
Fare = booking.Element("Fare").Value,
TravelInsurance = booking.Element("TravelInsurance").Value,
InFlightMeals = booking.Element("In-FlightMeals").Value,
LuggageAllowance = booking.Element("LuggageAllowance").Value,
ExtraLuggage = booking.Element("ExtraLuggage").Value,
CarHire = booking.Element("CarHire").Value,
ReturnTransfer = booking.Element("ReturnTransfer").Value,
};
//Inputs all of the values in bookings
foreach (var booking in query)
{
//Customer values
txtCustomerId.Text = txtCustomerId.Text + booking.CustomerId;
txttitle.Text = txttitle.Text + booking.Title;
txtfname.Text = txtfname.Text + booking.Firstname;
txtlname.Text = txtlname.Text + booking.Lastname;
txtdob.Text = txtdob.Text + booking.DateofBirth;
txtemail.Text = txtemail.Text + booking.Email;
txthouseno.Text = txthouseno.Text + booking.HouseNo;
txtstreet.Text = txtstreet.Text + booking.Street;
txtpostcode.Text = txtpostcode.Text + booking.Postcode;
txttown.Text = txttown.Text + booking.Town;
txtcounty.Text = txtcounty.Text + booking.County;
txtcontactno.Text = txtcontactno.Text + booking.ContactNo;
//Holiday Values
txtHolidayId.Text = txtHolidayId.Text + booking.HolidayId;
txthname.Text = txthname.Text + booking.HotelName;
txtl.Text = txtl.Text + booking.Location;
txtbf.Text = txtbf.Text + booking.BookFrom;
txtbt.Text = txtbt.Text + booking.BookTo;
txtcit.Text = txtcit.Text + booking.CheckInTime;
txtcot.Text = txtcot.Text + booking.CheckOutTime;
txtnorb.Text = txtnorb.Text + booking.NoOfRoomsBooked;
txtrt.Text = txtrt.Text + booking.RoomType;
txtrs.Text = txtrs.Text + booking.RoomServices;
txtpark.Text = txtpark.Text + booking.Parking;
txtpet.Text = txtpet.Text + booking.Pet;
//TravelInfo Values
txtTravelInfoId.Text = txtTravelInfoId.Text + booking.TravelInfoId;
txttf.Text = txttf.Text + booking.TravellingFrom;
txtd.Text = txtd.Text + booking.Destination;
txtf.Text = txtf.Text + booking.Fare;
txtti.Text = txtti.Text + booking.TravelInsurance;
txtifi.Text = txtifi.Text + booking.InFlightMeals;
txtla.Text = txtla.Text + booking.LuggageAllowance;
txtel.Text = txtel.Text + booking.ExtraLuggage;
txtch.Text = txtch.Text + booking.CarHire;
txtrtrans.Text = txtrtrans.Text + booking.ReturnTransfer;
}
MessageBox.Show("XML has been imported");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
如果有人知道我出错的地方或我需要添加/更改的内容，请告诉我们：）
非常感谢， 10gez10
答案 0 :(得分：1)
你有几个问题：
首先，您的数据元素不是booking元素的直接子元素，有中间元素<Customer>，<Holiday>和<TravelInfo>。因此，您需要执行类似
var query = from booking in doc.Descendants("Booking")
let customer = booking.Element("Customer")
let holiday = booking.Element("Holiday")
let travelInfo = booking.Element("TravelInfo")
select new
{
//Customer Elements
CustomerId = customer.Element("CustomerId").Value,
Title = customer.Element("Title").Value,
HolidayId = holiday.Element("HolidayId").Value,
TravelInfoId = travelInfo.Element("TravelInfoId").Value,
}
其次，几个元素拼写错误：
因此，当您执行（例如）Element("In-FlightMeals").Value时，Element()将返回null，因此您将获得空引用异常并且代码将被中止。
第三，元素BookTo完全缺失，因此BookTo = holiday.Element("BookTo").Value会生成空引用异常。
更一般地说，我不推荐这种编码方法。如果缺少任何XML元素，则查询将抛出异常，因为element.Element("name")将为null。更糟糕的是，Visual Studio似乎没有报告出现空引用的准确行号，而是提供select new语句的行号。并且（至少在我的版本上），也不可能进入匿名类型的构造函数。这使调试几乎不可能。
相反，跳过中间匿名类型并以更直接，更传统的方式执行操作：
foreach (var booking in doc.Descendants("Booking"))
{
var customer = booking.Element("Customer");
var holiday = booking.Element("Holiday");
var travelInfo = booking.Element("TravelInfo");
XElement element;
if (customer != null)
{
if ((element = customer.Element("CustomerId")) != null)
txtCustomerId.Text = txtCustomerId.Text + element.Value;
}
// And so on.
}