Problem setting the Error to the GridView Cell using the INotifyDataErrorInfo.

[SivaPrasad Bevara]

Hi,

I am using Telerik controls for silverlight 5 and Domain services.

I wanted to validate a filed against the database. I am using service method from the ViewModel to the validate that field.
As the Domain service is asynchronous, I am not able to set the error message to the RowEventArgs, once after the validation.

So I have implemented "INotifyDataErrorInfo" interfcae to notify the errors.

I am using "INotifyDataErrorInfo" in my ViewModel as below.

1) I have my DTO class in the server (EmployeeDTO in ther server project).

2) I am loading this object to the GridView through ViewModel.

3) In the "EmployeeDTO" I want to validate the "EmpId".
     For this I have created following 2 properties in the ViewModel
     a) CurrentItem (points to the seletedItem in the Grid)
     b) EmpId (points to the EmpId of the currentItem)

public EmployeeDTO CurrentItem
        {
            get { return _currentItem; }
            set { _currentItem = value; OnPropertyChanged("CurrentItem"); }
        }

public string EmpId
        {
            get { return CurrentItem.EmpId; }
            set
            {

                if (CurrentItem.EmpId != value)
                {
                    CurrentItem.EmpId = value;
                    OnPropertyChanged("EmpId");
                }
            }
        }

4) I am validating this field in the RowValidating event and setting the error as below in the
        operation_completed event of the Domain service.

AddErrorToPropertyAndNotifyErrorChanges("EmpId", new ValidationErrorInfo() 
            { ErrorMessage = "Should be Unique" });

NotifyErrorsChanged("EmpId");

    It is properly setting the error to that cell.
    
     But the problem is, its not displaying the error when I add the error message to that property(in the Operation_Completed event).
     This is displaying the error only when I go to that error field again.
      I mean its not noifying the error automatically when the error is set. 

     Does GridViewCell has any issue displaying the error on notification?

Please help.

Regards,
SivaPrasad.B