C# C.Net WinForms应用程序：匿名收集-如何分类返回类型

对我来说，这似乎是一个再出错的问题。当我使用匿名集合时，我再次遇到类型转换问题。我对XML文件的查询返回字符串值的集合。我试图将这些值从数据访问层返回到业务逻辑层。提前谢谢

    public string[] getCustDetails(string customerId)
    {
        //Pulls customer information for selected customer
        var doc = XDocument.Load("Portfolio.xml");
        var custRecord = from account in doc.Descendants("acct")
                         let acct = account.Element("acct")
                         where (string)account.Attribute("custid").Value == customerId
                         select new
                         {
                             Fname = (string)account.Attribute("fname").Value,
                             Lname = (string)account.Attribute("lname").Value,
                             Ssn = (string)account.Attribute("ssn").Value,
                             Dob = (string)account.Attribute("dob").Value,
                             Custid = (string)account.Attribute("custid").Value
                         };
return ?????

    }

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不能使用匿名类型作为方法的参数或返回类型

我建议创建一个具有所需属性的简单类，并使用它而不是匿名类型

public class AccountDetails
{
  public string FName { get; set; }
  public string LName { get; set; }
  public string Ssn { get; set; }
  public string Dob { get; set; }
  public string Custid { get; set; }
}

public IEnumerable<AccountDetails> getCustDetails(string customerId)
{
    //Pulls customer information for selected customer
    var doc = XDocument.Load("Portfolio.xml");
    var custRecords = from account in doc.Descendants("acct")
                     let acct = account.Element("acct")
                     where (string)account.Attribute("custid").Value == customerId
                     select new AccountDetails
                     {
                         Fname = (string)account.Attribute("fname").Value,
                         Lname = (string)account.Attribute("lname").Value,
                         Ssn = (string)account.Attribute("ssn").Value,
                         Dob = (string)account.Attribute("dob").Value,
                         Custid = (string)account.Attribute("custid").Value
                     };

    return custRecords;
}

---

为需求创建新类并将其作为列表返回

    public MyClass[] getCustDetails(string customerId)
    {
        //Pulls customer information for selected customer
        var doc = XDocument.Load("Portfolio.xml");
        var custRecord = (from account in doc.Descendants("acct")
                         let acct = account.Element("acct")
                         where (string)account.Attribute("custid").Value == customerId
                         select new MyClass
                         {
                             Fname = (string)account.Attribute("fname").Value,
                             Lname = (string)account.Attribute("lname").Value,
                             Ssn = (string)account.Attribute("ssn").Value,
                             Dob = (string)account.Attribute("dob").Value,
                             Custid = (string)account.Attribute("custid").Value
                         }).ToArray();
   return custRecord;

    }

将您的类定义为

public class MyClass
{
    public string Fname  { get; set; }
    public string Lname { get; set; }
    public string Ssn { get; set; }
    public string Dob { get; set; }
    public string Custid { get; set; }
}

---

我将创建一个包含以下属性的新类

 string Fname
 string Lname
 string Ssn
 string Dob
 string Custid

---

然后从getCustDetails方法返回此类型

此返回数组的外观如何？我不清楚您打算如何将匿名复合对象表示为字符串数组。如何键入返回到业务逻辑层的集合DLGetCustomers obj=new DLGetCustomers；？？某些集合类型应该是相同的：obj.getcustdailssorry，我真的很难处理这些通用集合。@Susan-鉴于我不知道您期望得到的回报是什么类型，我实在帮不了您。您可以使用建议的AccountDetails类的列表。