Save data from picker's selected item to firebase realtime database in xamarin form

Question

So I got this problem.
Our other platform( web) insert a data to firebase, data like product. So in our mobile which is I am assign to, I fetch those product data and display to a picker.
So this is How I fetch those data

   //My model  
           public int DeliveryPrice { get; set; }  
           public int PickUp_Price { get; set; }  
           public string gallonType { get; set; }  
           public string refillName { get; set; }  
         
           public int refill_id { get; set; }  
           public string waterType { get; set; }  
     
     
   //function where I fetch data from our database  
     
       public async Task<List<PRODUCT_REFILL>> GetAllProductRefill()  
           {  
               return   
                   (await firebaseClient.Child  
                   (nameof(PRODUCT_REFILL))  
                   .OnceAsync<PRODUCT_REFILL>()).Select(item => new PRODUCT_REFILL  
               {  
                     
                 DeliveryPrice=item.Object.DeliveryPrice,  
                 PickUp_Price=item.Object.PickUp_Price,  
                 gallonType=item.Object.gallonType,  
                 refillName=item.Object.refillName,  
                 waterType=item.Object.waterType,  
                 refill_id=item.Object.refill_id  
         
               }).ToList();  
           }  



   //My xaml  
       <Picker x:Name="Picker_ProductType"                                          
              ItemsSource="{Binding refillName}"  
             ItemDisplayBinding="{Binding refillName}">  
            <Picker.Items  >                                                         
                                               <x:String >  
                                               </x:String>   
                                                <x:String>  
                                               </x:String>  
              </Picker.Items>  
       </Picker>  
     
     
   //xaml.cs code behind  
       Product_RefillRepo productrefill = new Product_RefillRepo();  
         
       async protected override void OnAppearing()  
           {  
              var productRefill = await productrefill.GetAllProductRefill();  
               Picker_ProductType.ItemsSource = productRefill;  
         
            }  

Then in my code behind also I have an button_clicked event and inside that, I have this line.
string orderProductType = Picker_ProductType.SelectedItem.ToString();

but I when I click the order button, I got this error.
Error says; System.InvalidCastException: 'Specified cast is not valid.'

Please help me if how to fix that error cause I cant insert data to firebase realtime. Thank you so much.

Answer 1

Hello,

When you use Picker_ProductType.SelectedItem, you get the PRODUCT_REFILL object, if you want to the value of refillName, you need to cast Picker_ProductType.SelectedItem to PRODUCT_REFILL, then you can get the refillName like following code.

   private void OnBtnClicked(object sender, EventArgs e)  
       {  
           PRODUCT_REFILL pRODUCT_REFILL = Picker_ProductType.SelectedItem as PRODUCT_REFILL;  
           string orderProductType=pRODUCT_REFILL.refillName;  
       }  

Best Regards,

Leon Lu

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