CODEWITHSUNDEEP
c#entity-frameworkinterface
Vic
Vic

Reputation: 497

Set interface us a properties c#

I've created three interfaces - IUser, ICostCenter, IDepartment. IUser and IDepartment are properties of ICostCenter.

public interface ICostCenter
{
    IDepartment Department { get; set; }
    User.IUser CostCenterHead { get; set; }
}

The class implementing ICostCenter will be used in the DbContext for my db.

public class tblCostCenter : WorkingInterface.Interface.Organization.ICostCenter
{
    public tblCostCenter()
    {
        this.ID = Guid.NewGuid().ToString();
    }

    public string ID { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }

    private WorkingInterface.Interface.User.IUser CostCenterHead { get; set; }
    public string UserID { get; set; }
    [ForeignKey("UserID")]
    public Model.tblUser UserObject
    {
        get { return (Model.tblUser)this.CostCenterHead; }
        set { this.CostCenterHead = value; }
    }

    private WorkingInterface.Interface.Organization.IDepartment Department { get; set; }
    public string DepartmenID { get; set; }
    [ForeignKey("DepartmenID")]
    public Model.tblDepartment DepartmentObject
    {
        get { return (Model.tblDepartment)this.Department; }
        set { this.Department = (Model.tblDepartment)value; }
    }
}

I'm getting an error because I made the IUser and IDepartment properties private. How can I properly implement the interface? I want these properties to be hidden.

Upvotes: 0

Views: 55

Answers (1)

Chris Schaller
Chris Schaller

Reputation: 16554

The interface is declared explicitly as public, that means that all the members declared in that interface MUST be public

So you need to declare both of these properties as public:

public WorkingInterface.Interface.User.IUser CostCenterHead { get; set; } public WorkingInterface.Interface.Organization.IDepartment Department { get; set; }

NOTE: these have been declared as implicit implementations, so they are available to all contexts. If you want to hide them from general use, you can use explicit implementation.

Because you tried to use private accessibility, I assume you generally want to hide these properties from view, you can do this and still honor the interface contract by using explicit implementation syntax:

WorkingInterface.Interface.User.IUser ICostCenter.CostCenterHead { get; set; } WorkingInterface.Interface.Organization.IDepartment ICostCenter.Department { get; set; }

They are still public but can only be accessed by first casting the object to the specific interface type explicitly.

tblCostCenter obj = new tblCostCenter();
...
// this wont work:
Console.WriteLine(obj.CostCenterHead);
// instead you will have to cast the object first
Console.WriteLine((obj as ICostCenter)).CostCenterHead);
// or if the local variable was an ICostCenter
ICostCenter costObj = obj;
Console.WriteLine(costObj.CostCenterHead);
...
// Pattern matching can also be helpful in these scenarios
if (obj is ICostCenter cc)
     Console.WriteLine(cc.CostCenterHead);

If you want to use explicit declaration in your class you could try this:

WorkingInterface.Interface.User.IUser ICostCenter.CostCenterHead { get; set; }
public string UserID { get; set; }
[ForeignKey("UserID")]
public Model.tblUser UserObject
{
    get { return ((ICostCenter)this).CostCenterHead as Model.tblUser; }
    set { ((ICostCenter)this).CostCenterHead = value; }
}

WorkingInterface.Interface.Organization.IDepartment ICostCenter.Department { get; set; }
public string DepartmenID { get; set; }
[ForeignKey("DepartmenID")]
public Model.tblDepartment DepartmentObject
{
    get { return ((ICostCenter)this).Department as Model.tblDepartment; }
    set { ((ICostCenter)this).Department = value; }
}

this only works if:

  • Model.tblDepartment : IDepartment
  • Model.tblUser : User.IUser

Upvotes: 1

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