How not to reload CollectionView after clicking on Back button

Question

Hi I'm facing a problem with my small xamarin app.

I have my small xamarin-form app that everytime the user enter a product Id click OK button retrieves a single (data related to that product Id only) data thru Web API from page A, and then pass it to a collectionview in another page B.

then there is a back button to go back to page A and the user must enter another product Id again and the app must fetch data thru web api again and pass it again to page B in the collectionview.

So the problem is now, when I click on back button in Page B, it's clear the collectionview data, whereas I need the collectionview to keep the state even If I pop back.

I'm not using any MVVM pattern or complicated stuff from now as I'm new to xamarin; it's just a simple architecture.

Or maybe I'm using wrong technics to achieve this and can advise me a better way to achieve that. I'm please open to your suggestion !!!

In brief, I need to be able not to reload CollectionView after clicking on Back button.

Below is the code that Bind to the View on Page B

public async void OnGetProductDetailButton(object sender, EventArgs e)
{

await Navigation.PushAsync(new ProductDetailPage
{
    BindingContext = productDetails
});

}

Answer 1

Hello,

Welcome to Microsoft Q&A!

We could create a global variable to store the data from Web API in page A ,and pass the data when pushing to page B .

   private ProductDetail productDetails ;  
     
   public async void OnGetProductDetailButton(object sender, EventArgs e)  
   {  
     
       if(productDetails == null){  
            //call web api  
           // productDetails  = data;   
     
       }  
       await Navigation.PushAsync(new ProductDetailPage  
       {  
           BindingContext = productDetails  
       });  
   }  

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