Question

I have an enum and a usercontrol, both in the same assembly (a plain .NET 4 web site).

In the Constants class:

public Enum CrudOperations
    Add
    Edit
    Delete

This controls the columns in a GridView on a UserControl via a property on the UserControl

Public Property Mode() As CrudOperations
        Get
            Return [Enum].Parse(GetType(CrudOperations), If(ViewState.Item("Mode"), "0"), True)
        End Get
        Set(ByVal value As CrudOperations)
            ViewState.Item("Mode") = value
            grdItems.Columns(3).Visible = ((value Or CrudOperations.Add) = CrudOperations.Add)
            grdItems.Columns(4).Visible = ((value Or CrudOperations.Edit) = CrudOperations.Edit)
        End Set
End Property

In C#, I’ve specified the columns to show with markup as Mode="Edit,Delete", but in VB.NET, this does nothing. The only way I can get anything to show is with the codebehind, but if on the containing page I use userGrid.Mode = CrudOperations.Edit And CrudOperations.Delete, I get all the columns (there’s also a delete column), but userGrid.Mode = CrudOperations.Edit Or CrudOperations.Delete shows nothing.

Is there a way to do the C# equivalent?

Answer 1

You need to use the Flags attribute where an enumeration can be treated as a bit field.

C#:

[Flags] 
public enum CrudOperations 
{ 
    Add, 
    Edit, 
    Delete  
}

userGrid.Mode = CrudOperations.Edit | CrudOperations.Delete;

VB.NET:

<Flags> _
Public Enum CrudOperations
    Add
    Edit
    Delete
End Enum

Private test As CrudOperations = CrudOperations.Edit Or CrudOperations.Delete