DataForm Validation

[Harald]

Hello,

how can I prevent the user can exit the form?

private void AddressDetails_ValidatingItem(object sender, System.ComponentModel.CancelEventArgs e)
        {
            Address address = this.AddressDetails.CurrentItem as Address;
            try
            {
                if (address.LastName == null)
                {
                    throw new ValidationException("Das Feld Nachname darf nicht leer sein.");
                }
                //Save Changes
                SaveChanges();
            }
            catch (ValidationException ex)
            {
               RadWindow.Alert(ex.Message);
            }
        }

[Stefan]

Hi Harald,

Can you please share some details on what exactly do you mean by exiting the form?

Additionally, I suggest you taking a look at our documentation on Validation, as the supported by RadDataForm validation approaches are demonstrated in it. You may also find the DataForm Validation - ValidatingItem() useful on the matter.

Regards,
Stefan X1
Telerik

[Harald]

If a required field is empty, the Click on Commit-Button show a Alert and the User can´t leave the Editmode of the DataForm.

[Petya]

Hi Harald,

One way to achieve that is through the CancelEventArgs exposed by the ValidatingItem event. Just set the Cancel property to true:

if (address.LastName == null)
    {
        throw new ValidationException("Das Feld Nachname darf nicht leer sein.");
        e.Cancel = true;
    }

Hope this helps.

Regards,
Petya
Telerik