No, you cannot have a delegate as an attribute constructor parameter. See available types: Attribute parameter types
As a workaround (although it’s hacky and error prone) you can create a delegate with reflection:
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface, AllowMultiple = false, Inherited = true)]
public class WorkspaceAttribute : Attribute
{
public ConnectionPropertiesDelegate ConnectionDelegate { get; set; }
public WorkspaceAttribute(Type delegateType, string delegateName)
{
ConnectionDelegate = (ConnectionPropertiesDelegate)Delegate.CreateDelegate(typeof(ConnectionPropertiesDelegate), delegateType, delegateName);
}
}
[Workspace(typeof(TestDelegate), "GetConnection")]
public class Test
{
}