CODEWITHSUNDEEP
mvvmmauicommunity-toolkit-mvvm
Sam
Sam

Reputation: 30334

Query Parameters in ViewModels in .NET MAUI

In the Podcast sample app, I see that query parameters are received directly in view models -- as you can see here: https://github.com/microsoft/dotnet-podcasts/blob/main/src/Mobile/ViewModels/EpisodeDetailViewModel.cs

I tried this in my view model but I'm not getting any values i.e. null. I currently do it through code behind but I'd like to do it directly in the ViewModel.

Here's my current approach:

MyPage.xaml.cs

[QueryProperty(nameof(Id), nameof(Id))]
public partial class MyPage: ContentPage
{
   public string Id { get; set; }
   MyPageViewModel _vm;
   public MyPage(MyPageViewModel vm)
   {
       InitializeComponent();
       _vm = vm;
       BindingContext = _vm;
   }

   protected override void OnAppearing()
   {
      base.OnAppearing();
      _vm.InitAsync(Id);
   }
}

MyPageViewModel.cs

public partial class MyPageViewModel : BaseViewModel
{
   IMyService _myService;
   public MyPageViewModel(IMyService myService)
   {
      _myService = myService;
   }

   public async void InitAsync(string id)
   {
      // Get data
      var data = await _myService.Get(id);
   }
}

I'd like to simplify the approach and receive my query parameters directly in my view model.

How do I get my query parameters directly in my view model?

Upvotes: 0

Views: 1610

Answers (1)

lokesh
lokesh

Reputation: 330

You may use MVVM toolkit Docs

[ObservableProperty]
private string? name;

partial void OnNameChanging(string? value)
{
    Console.WriteLine($"Name is about to change to {value}");
}

partial void OnNameChanged(string? value)
{
    Console.WriteLine($"Name has changed to {value}");
}

Upvotes: 0

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