Not able to pass parameters to a shell content page

Question

I have created a shell page and trying to call a content page as per following code in xamarin forms public

 AppShell() { Routing.RegisterRoute("itemdetails", typeof(ItemDetailPage)); }

Following is the event on which i am calling content page - itemdetails page alongwith selected categoryid as parameter

   private async void CategoriesCollectionView_SelectionChanged(object sender, SelectionChangedEventArgs e) 
  {
    int selectedCategoryId = ((CategoryMasterWithImage)e.CurrentSelection[0]).CategoryId; 
    Application.Current.Properties["SelectedCategoryId"] = selectedCategoryId.ToString(); 
    await Shell.Current.GoToAsync($"itemdetails?name={selectedCategoryId}"); 

  public ItemDetailPage(int categoryId) 
  { 
      InitializeComponent(); 
      productCategoryId = categoryId; 

   } 

This is constructor of ItemDetailPage.. When i am calling this is saying: No Default Constructor found for ItemDetailPage

Answer 1

Hello,

Welcome to our Microsoft Q&A platform!
When you used the following code to pass parameter to next pageItemDetailPage` ,

  await Shell.Current.GoToAsync($"itemdetails?name={selectedCategoryId}");   

We could get the passed data by using QueryProperty to get the data in next page ItemDetailPage, and we should add a default constructor for Page ItemDetailPage ,for example:

[QueryProperty(nameof(ProductCategoryId), "name")]  
public partial class ItemDetailPage : ContentPage  
{  
    public string ProductCategoryId  
    {  
        set  
        {  
            LoadData(value);  
        }  
    }  
  
    void LoadData(string id)  
    {  
        try  
        {  
            Console.WriteLine(" the passed data ProductCategoryId = " + id);      
            // set BindingContext for you page      
        }  
        catch (Exception)  
        {  
            Console.WriteLine("Failed to load animal.");  
        }  
    }  
  
    public ItemDetailPage()  
    {  
        InitializeComponent();  
  
        //BindingContext = new ItemDetailViewModel();  
    }  
}  

For more details, you can check: https://learn.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/shell/navigation#pass-data

You can also refer to the sample :https://github.com/xamarin/xamarin-forms-samples/blob/master/UserInterface/Xaminals/Xaminals/Views/CatDetailPage.xaml.cs

Best Regards,

Jessie Zhang

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