我有一個viewmodel,它使用valueinjector從模型(我也實現了TPT繼承)注入值。在此過程中,由於我的自定義屬性(屬性不是在模型中源)中的一個,我不斷收到以下錯誤:視圖模型中的定製屬性在TPT繼承項目中使用valueinjector
Object reference not set to an instance of an object.
我發現valueinjector不斷去該屬性每一個現在,然後。如下面的示例所示,自定義屬性是「FullName」。
public class EmployeeVm
{
public EmployeeVm(Employee employee)
{
this.InjectFrom<Employee>(employee);
}
public EmployeeVm(int id):this(new Context().Employees.Find(id))
{
}
public EmployeeVm()
{
}
public int EmployeeId { get; set; }
[Display(Name = "First Name")]
[Required(ErrorMessage = "Pleae enter First Name"), StringLength(50)]
public string FirstName { get; set; }
[Display(Name="Middle Name"), StringLength(50)]
public string MiddleName { get; set; }
[Display(Name="Last Name"), StringLength(50)]
[Required(ErrorMessage = "Please enter Last Name")]
public string LastName { get; set; }
public string FullName {
get
{
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.Append("<b>");
stringBuilder.Append(LastName.ToUpper());
stringBuilder.Append("</b>");
if (!string.IsNullOrEmpty(MiddleName))
{
stringBuilder.Append(", ");
stringBuilder.Append(MiddleName);
}
stringBuilder.Append(", ");
stringBuilder.Append(LastName);
return stringBuilder.ToString();
}
}
}
掠過我心中唯一的解決方案是讓valueinjector忽略屬性,使之不會嘗試設置其他屬性之前獲得的財產。爲此,我試着寫定製注射器在員工型號如下:
[Table("Person")]
public abstract class Person:ConventionInjection
{
public Person()
{
this.PersonAddresses = new List<PersonAddress>();
this.PersonEmails = new List<PersonEmail>();
this.PersonPhones = new List<PersonPhone>();
}
[Key]
public int PersonId { get; set; }
public string FirstName { get; set; }
public string MiddleName { get; set; }
public string LastName { get; set; }
//public virtual Employee Employee { get; set; }
protected override bool Match(ConventionInfo c)
{
throw new NotImplementedException();
}
public List<PersonAddress> PersonAddresses { get; set; }
public List<PersonEmail> PersonEmails { get; set; }
public List<PersonPhone> PersonPhones { get; set; }
}
public class Employee:Person
{
public Employee()
{
this.Identifications=new List<Identification>();
this.BankAccounts=new List<BankAccount>();
}
public DateTime? DateOfBirth { get; set; }
//Other properties are inherited from Person abstract class
public virtual ICollection<Identification> Identifications { get; set; }
public virtual ICollection<BankAccount> BankAccounts { get; set; }
protected override bool Match(ConventionInfo c)
{
if (c.TargetProp.Name == "FullName")
{
return false;
}
var isMatch = (c.SourceProp.Name == "PersonId" && c.TargetProp.Name == "EmployeeId") ||
(c.SourceProp.Name == c.TargetProp.Name && c.SourceProp.Type == c.TargetProp.Type);
return isMatch;
}
}
在-雖然如此,我一直得到相同的上述錯誤。
我還發現另一個解決方案,它說覆蓋LoopValueInjection的UseSourceProp方法。
http://valueinjecter.codeplex.com/discussions/234706
但是,它不是那麼容易在我的情況,我已經在我的基類和派生類繼承的一個類。並且爲了實現自定義valueinjector也不可能,因爲您可以從EmployeeVm viewmodel中看到它。
this.InjectFrom<Employee>(employee);
如果有人能幫助我實現這個實現或者有其他解決方案,我將不勝感激。
另外,thanx爲觀衆。
非常感謝。它工作得很好。天才 ... –