how to use parameter in viewmodel ins xamarin.forms

user_69963 0
Viewed 3582

Im trying to pass parameter to viewmodel in Xamarin.Forms.But Also I want to use it while loading the page ,to call a rest service with that parameter.But In load event parameter is null always.(I can see that parameter if I bind it to a label or etc...) How can I make it work properly and use that parameter inside the load event of viewmodel? Any help is appreciated,thanks

here is the button click event and navigate to Samplepage.

 private void OntaptedBildirimItem(string param)
    {
      this._navigationService.NavigateTo(nameof(Views.SamplePage), param);
    }

this is the Sample Page Viewmodel

      private string _id;
    public string id
    {
        get
        {
            return _id;
        }
        set
        {
            Set(() => id, ref _id, value);
        }
    }    
public SamplePageViewModel(INavigationService navigationService) : base(navigationService)
    {
        this._navigationService = navigationService;
        this.Title = "Sample Page=" + id; // here the id is always null,but if I use it to bind a label in xaml ,it has a value.
    }

This is the SamplePage Code 

     public SamplePage(string parameter)
    {
        InitializeComponent();
        var viewModel = this.BindingContext as ViewModels.SamplePageViewModel;
        if(viewModel != null && parameter != null)
        {
            viewModel.bildirimid = parameter;
        }
    }
xamarin.forms xamarin mvvm visual-studio c#
2 Answers

Thx for this Miguel ,this helps me a lot ,I can do what I want by this approach .You can send parameter while navigating a page in xamarin.forms like this

_navigationService.NavigateToAsync<SamplePageViewModel>("Your_parameter"); and you can get that parameter in that page's viewmodel like this

 public override async Task InitializeAsync(object yourparameter)
        {
            // use yourparameter as you wish
        }
user_699630

We need see NavigationService .

You should add bindingContext in NavigationService not in SamplePage.

In This Sample uses NavigationService with a parameter and a better NavigationService structure. You should see it.

Send feedback please.

user_79337830
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