private async void Friend_ItemTapped(object sender, ItemTappedEventArgs e) { Trace.WriteLine("DAAN"); bool MemberAlready = false; User selectedUser = FriendsList.SelectedItem as User; foreach (int x in GroupMembers) { Trace.WriteLine("Member id " + x); if (x == selectedUser.ID) { MemberAlready = true; break; } } if (!MemberAlready) { var action = await DisplayAlert((FriendsList.SelectedItem as User).Username, "Add to Participants?", "Yes", "No"); if (action) { gc.AddRemoveMember(group.Id, selectedUser.ID, "add", this, uc.currentUser.Username, uc.currentUser.ID); } } else { var action = await DisplayAlert((FriendsList.SelectedItem as User).Username, "Remove as Participant?", "Yes", "No"); if (action) { gc.AddRemoveMember(group.Id, selectedUser.ID, "remove", this, uc.currentUser.Username, uc.currentUser.ID); } } }