private async void Button_Clicked(object sender, EventArgs e)
        {
            if (!Regex.IsMatch(this.Naziv.Text, @"^[a-zA-Z ]+$"))
            {
                await DisplayAlert("Greška", "Naziv se sastoji samo od slova", "OK");
            }
            else
            {
                try
                {
                    ZanrInsertRequest req = new ZanrInsertRequest()
                    {
                        Naziv = this.Naziv.Text,
                    };

                    await _apiServiceZanr.Update <dynamic>(zanrVM.Zanr.ZanrID, req);
                    await DisplayAlert("OK", "Uspješno uneseni podaci", "OK");

                    // await  Navigation.PushAsync(new ZanrPage());
                }
                catch (Exception err)
                {
                    throw new Exception(err.Message);
                }
            }
        }
 private async void btnSnimi_Click(object sender, EventArgs e)
 {
     if (this.ValidateChildren())
     {
         var request = new ZanrInsertRequest()
         {
             Naziv = txtNaziv.Text
         };
         if (_id.HasValue)
         {
             await _apiService.Update <Model.Zanr>(_id.Value, request);
         }
         else
         {
             await _apiService.Insert <Model.Zanr>(request);
         }
         MessageBox.Show("Uspješno sačuvani podaci");
         this.Close();
     }
 }