在另一个C＃类中创建一个对象？

Question

我正在进入oop的第一步，这需要对我的应用程序进行彻底删除，并将其重新设计为3层和面向对象。 叹息。我有一个提交对象，它应该包含一个客户对象（以及一个代理和覆盖对象）;我想在每个包含的对象的字段中存储来自数据库的一些datareader结果，但是当我尝试用新的提交对象调用Customer对象时，我什么也得不到。 VS不承认提交包含一个Customer对象。我明显错过了一些关键点，所以考虑到这一点，想法？下面的代码。

//This is the Submission class here 
public class Submission 
{ 
    public int SubmissionId {get;set;} 
    public int Status { get; set; } 
    public string StatusComment { get; set; } 


    public class Customer 
    { 
     //public Customer() { } 
     public int CustId { get; set; } 
     public string CustName { get; set; } 
     public string CustAddress { get; set; } 
     public string CustState { get; set; } 
     public string CustCity { get; set; } 
     public int CustZip { get; set; } 
     public int SicNaic { get; set; } 

    } 

    public object Customer(); 
} 


//These lines throw an error: 

无法通过表达式引用类型。 VS无法识别TempSubmission.Customer在提交内部对Customer对象的调用。

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Data; 
using System.Data.SqlClient; 


/// This query should selects the relevant data for a gridview on the presentation layer and stores in a list. 
/// Don't quite know how to bind it to the gridview yet, but that's a different question. 

public class SubmissionDatabaseService 
{ 
    public List<Submission> GetAllSubmissions() 
    { 
     string Searchstring = "SELECT Submission.SubmissionId, Customer.CustName, Customer.CustCity, Customer.CustState, Broker.BroName, Broker.BroState, Broker.EntityType, Submission.Coverage, Status.Status FROM Submission INNER JOIN Broker ON Broker.BroId = Submission.BroId INNER JOIN Customer ON Customer.CustId = Submission.CustId INNER JOIN Status ON Status.StatusId = Submission.StatusId"; 
     string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;   
     SqlConnection conn = new SqlConnection(connectionString); 

     SqlDataReader dr = null; 

     try 
     { 
      conn.Open(); 

      SqlCommand Searchcmd = new SqlCommand(Searchstring, conn); 

      dr = Searchcmd.ExecuteReader(); 
      List <Submission> lstSubmission; 
      Submission tempSubmission; 
      while (dr.Read()) 
      { 
       tempSubmission = new Submission(); 
       tempSubmission.SubmissionId = dr.GetInt32(0); 
       tempSubmission.Customer.CustName = dr.GetString(1); 
       tempSubmission.Customer.CustCity = dr.GetString(2); 
       tempSubmission.Customer.CustState = dr.GetString(3); 
       tempSubmission.Broker.BroName = dr.GetString(4); 
       tempSubmission.Broker.BroState = dr.GetString(5); 
       tempSubmission.Broker.EntityType = dr.GetString(6); 
       tempSubmission.SubmissionCoverage.Coverage = dr.GetInt32(7); 
       tempSubmission.Status = dr.GetInt32(8); 

       //Add rest of the fields 
       lstSubmission.Add(tempSubmission); 
      } 
     } 

     return lstSubmission; 
    } 
} 

Answer 1

Ooo ..从哪里开始？把你的客户类它自己的文件Customer.cs，并在其自己的文件Submission.cs您所提交的类

然后，你可以做一个简单的提交类，像这样：

public class Submission 
{ 
     // consider implementing the below as properties to more finely control access 
     public int SubmissionId; 
     public int Status; 
     public string StatusComment; 
     public Customer SubmissionCustomer; // <-- this is null until you set it to a Customer object, either in the constructor or externally. 

     public Submission() { 
      // constructor 
     } 

} 

然后在属性念起来建设者，并将它们洒在你认为合适的地方。请参阅：

http://msdn.microsoft.com/en-us/library/x9fsa0sw(v=vs.80).aspx

性能有私人/公共模式。至于构造函数：

参见：

http://msdn.microsoft.com/en-us/library/ace5hbzh.aspx

构造函数的调用，只要你创建一个类的实例（对象）。

Answer 2

只需在提交内定义客户对象，不会使提交包含客户的实例。对于您想要执行的操作，只需将“客户”提交到“提交”外并在“提交”中定义“客户”属性。

Answer 3

您正试图通过tempSubmission参考实际类型Customer。您必须改为参考Customer的实例，该实例将通过某个物业或类似物品展示。

Answer 4

问题是您的客户类型不够具体，它被定义为对象而不是客户。

达到你想要做的，你将不得不在这种情况下Customer类型的属性添加一个新成员到您Submission类，你public object Customer();做了什么基本meams，定义一个名为类型的对象Customer方法。

，你会想要做的是确定什么，例如RelatedCustomer

Public Customer RelatedCustomer{get;set;} 

Answer 5

我想你想要什么是Customer类是提交类之外，为被叫Customer类型的属性提交类包含Customer的一个实例。

public class Submission 
{ 
    public Submission() 
    { 
     this.Customer = new Customer(); 
    } 

    public int SubmissionId { get; set; } 
    public int Status { get; set; } 
    public string StatusComment { get; set; } 
    public Customer Customer { get; set; } 
} 
public class Customer 
{ 
    //public Customer() { } 
    public int CustId { get; set; } 
    public string CustName { get; set; } 
    public string CustAddress { get; set; } 
    public string CustState { get; set; } 
    public string CustCity { get; set; } 
    public int CustZip { get; set; } 
    public int SicNaic { get; set; } 
}