Xamarin Portable OnAppearing() XAML page loading

Question

i am using the Xamarin Forms Portable project and i am using the MVVM method. Right now I am stuck. I want to build a LOADING page. So when the (Custom) Page starts it must load a XAML page loading and when the Loading (call to a webservice) is done the XAML page loading must be set to visible = false.

I have the next code that wont work:

    protected override async void OnAppearing()
    {

        base.OnAppearing();

        var page = Navigation.PushAsync(new ActivityIndicatorPage());

        await Task.Delay(1000);

        BindingContext = new ProductViewModel(_ProductId);

    }

So how do i Call the 'ActivityIndicatorPage' Page and then set it to invisible after the 'BindingContext = new ProductViewModel(_ProductId);' call is done.

Thanx.

Answer 1

You need an AcitvityIndicator Just include this code in your xaml page where you want to show the loading and bind IsVisible property of StackLayout or whatever you choose as a container.

<StackLayout HorizontalOptions="Center" VerticalOptions="Center" IsVisible="{Binding IsLoading}">
    <ActivityIndicator Color="Red" IsRunning="true" />
</StackLayout>

then you can set its bindable property(or name of StackLayout whatever in your case) to true or false based on your background task completion for example: in your code behind or in viewModel you can do something like this

public async Task<bool> MyBackgroundTask(){
    IsLoading=true
    //your background task
    if(successful){
        IsLoading = false
    }
}