can abstract class inherit another abstract class c#

Question

I'm beginner in C# & EF. I got a silly doubt while designing my new sample aplication. Can an abstract inherits another abstract class

using System;
using System.ComponentModel.DataAnnotations;

namespace Spark.BusinessObjects.Common
{
   public abstract class BOBase
   {
    public virtual int UpdatedBy { get; set; }

    [DataType(DataType.DateTime)]
    public virtual DateTime UpdatedOn { get; set; }
 }

  public abstract class MasterBOBase : BOBase
 {
    public virtual int CreatedBy { get; set; }

    [DataType(DataType.DateTime)]
    public virtual DateTime CreatedOn { get; set; }
 }
}

namespace Spark.BusinessObjects.UserManagement
{
 using System;
using System.Data.Linq.Mapping;
using System.ComponentModel.DataAnnotations;

using Spark.BusinessObjects.Common;

[Table(Name = "tblUser")]
public class User:BOBase
{
    [Key]        
    public virtual int UserID { get; set; }

    [StringLength(maximumLength:40,MinimumLength=10)]
    [DataType(DataType.EmailAddress)]
    public virtual string EMailID { get; set; }

    [StringLength(maximumLength: 20, MinimumLength = 6)]
    [DataType(DataType.Password)]
    public virtual string Password { get; set; }

    [StringLength(maximumLength: 20, MinimumLength = 3)]
    public virtual string FirstName { get; set; }

    [StringLength(maximumLength: 20, MinimumLength = 1)]
    public virtual string LastName { get; set; }

    [DataType(DataType.Date)]
    public virtual DateTime DOB { get; set; }

}

public class UserRole:MasterBOBase
{
    [Key]
    public virtual int UserID { get; set; }
    public virtual  int UserRoleName { get; set; }
}
}

I don't need CreatedBy & CreatedOn properties in my master tables.Can i use like above. Is it correct?

Answer 1

Sure, an abstract class can inherit from another class!!

The only time a class cannot inherit from another is when the class you wish to inherit from is sealed or has private constructors only.

Answer 2

Yes you can inherit an abstract class from another abstract class.

You can find a example below:

public abstract class BaseClass1
{
    public abstract string Method();
}

public abstract class BaseClass2 : BaseClass1
{
}

public class UserClass : BaseClass2
{
    string name;
    public override string Method()
    {
      return name;
    }
}

If you want to use the method Method() in BaseClass2 also you can override the method from BaseClass1

in BaseClass2 you can putpublic override abstract string Method(); within in, but with or without it the intended action is moreover the same.