Windows.ApplicationModel.Contacts.ContactPicker.PickSingleContactAsync C# (CSharp) Method

		public extern IAsyncOperation<ContactInformation> PickSingleContactAsync();
		public extern IAsyncOperation<IVectorView<ContactInformation>> PickMultipleContactsAsync();

        /// <summary>
        /// The click Event. This event will decide wheather to allow Single contact pick or allow used to select multiple
        /// contacts.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void btnCallContact_Click(object sender, RoutedEventArgs e)
        {
            SingleContactDetails = new List<Store_CS_WorkingwithContacts.ContactDetails>(); 
            var contactSelector = new Windows.ApplicationModel.Contacts.ContactPicker();
            //Set the text for the commit button of the ContactPicker UI
            contactSelector.CommitButtonText = "Pick Contact";


            if (selectionType == "Single")
            {
                //Select Single Contact
                var selectedContact = await contactSelector.PickSingleContactAsync();
               SingleContactDetails.Add(new ContactDetails(selectedContact));
            }
            else
            {
                if (selectionType == "Multiple")
                {
                    //Select Multiple Contacts
                    var selectedContact = await contactSelector.PickMultipleContactsAsync();

                    foreach (var item in selectedContact)
                    {
                        SingleContactDetails.Add(new ContactDetails(item));
                    }
                }
                else
                {
                    txtmessage.Text = "Please Select the option";
                }
               
            }
            lstcontactsdetails.ItemsSource = SingleContactDetails;

        }