Delete Button in ListView

public override View GetView(int position, View convertView, ViewGroup parent)
        {
            View view = convertView; // re-use an existing view, if one is available
            if (view == null) // otherwise create a new one
            {
                view = context.LayoutInflater.Inflate(Resource.Layout.AccountAddedListItem, null);
            }
            TextView txtAddedAs,txtName;
            Button btnDelete;
            txtAddedAs = view.FindViewById<TextView>(Resource.Id.tvAddedAs);
            txtName = view.FindViewById<TextView>(Resource.Id.tvName);
            btnDelete = view.FindViewById<Button>(Resource.Id.btnDelete);       
            txtAddedAs.Text = AccountsAdded[position].added_as.ToString ();
            txtName.Text = AccountsAdded[position].name.ToString ();
            btnDelete.Click += (object sender, EventArgs e) => {
                AccountsAdded.RemoveAt (position);
                this.NotifyDataSetChanged();
                };
            if(AccountsAdded[position].cancellable)
                btnDelete.Visibility = ViewStates.Gone ;
            else
                btnDelete.Visibility = ViewStates.Visible;
            return view;
        }

i created a custom adapter for a listview also i created custom layout. i don't know why the delete button event handler called twice when i click the delete button. any idea. thanks in advance