Xamarin Xamarin shell 页之间发送64格式图片

Question

I apologize in advance for my poor spelling due to my reliance on google translate

When sending an image in 64 format between Xamarin shell pages, the property is not affected in the recipient ViewModel

Here is the query sending code

await Shell.Current.GoToAsync(
    state: $"{nameof(SuppliersByProdectID)}?" +
    $"{nameof(Suppliers.SuppliersByProdectID.ItemId)}={item.AIItemId}" + "&" +
  //
  //Image property is string here
  //
    $"{nameof(Suppliers.SuppliersByProdectID.Image)}={item.AIItemImage}");

Here is the Query receipt code

[QueryProperty(nameof(ItemId), nameof(ItemId))]
[QueryProperty(nameof(Image), nameof(Image))]
public class SuppliersByProdectID : MyBaseViewModel
{
    private string image;
    public string Image
    {
        get => image;
        set
        {
            //I set a breakpoint here, but the program does not stop 
            //at it
            SetProperty(ref image, value);
            ItemImage = ImagesConverter.GetImageSource(value);
        }
    }

    private ImageSource itemImage;
    public ImageSource ItemImage
    {
        get => itemImage;
        set => SetProperty(ref itemImage, value);
    }

    private string itemId;
    public string ItemId
    {
        get => itemId;
        set
        {
            SetProperty(ref itemId, value);
            FillSuppliers();
        }
    }
}

Execution does not pass the Image property, although it carries a value in the ViewModel dispatch, and this is when the execution is stopped with a breakpoint

Answer 1

If you want to transfer string of Image to ViewMode l of navigated page. You can use Process navigation data using a single method to achieve it.

Navigation data can be received by implementing the IQueryAttributable interface on the ViewModel : SuppliersByProdectID .The following example shows a view model class that implements the IQueryAttributable interface:

public class MonkeyDetailViewModel : IQueryAttributable, INotifyPropertyChanged
{
    public Animal Monkey { get; private set; }

    public void ApplyQueryAttributes(IDictionary<string, string> query)
    {
        // The query parameter requires URL decoding.
        string name = HttpUtility.UrlDecode(query["name"]);
        LoadAnimal(name);
    }

    void LoadAnimal(string name)
    {
        try
        {
            Monkey = MonkeyData.Monkeys.FirstOrDefault(a => a.Name == name);
            OnPropertyChanged("Monkey");
        }
        catch (Exception)
        {
            Console.WriteLine("Failed to load animal.");
        }
    }
    ...
}

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