How to create a ReactiveCommand that receives a string in ReactiveUI 7 with Xamarin Forms

2
votes

In my LoginPage.xaml.cs I have a webview wview. I want to execute a command in my ViewModel when the Navigated event is triggered om my wview. My command should receive the url from my webview.

LoginPage.xaml.cs:

protected override void OnAppearing()
{
    base.OnAppearing();
    Observable.FromEventPattern<WebNavigatedEventArgs>(
        ev => wview.Navigated += ev,
        ev => wview.Navigated -= ev)
        .Select(x => x.EventArgs.Source.ToString())
        .InvokeCommand(ViewModel.VerifyCallbackUrl);
}

How do I create a command that can react on this? The following code doesn't compile (Delegate action does not take 1 argument) :

public ReactiveCommand<string,System.Reactive.Unit> VerifyCallbackUrl { get; protected set; }

public LoginViewModel(IScreen hostScreen = null) : base(hostScreen) 
{   
    VerifyCallbackUrl = ReactiveCommand<string, System.Reactive.Unit>
        .Create(xUrl => 
        {
            DoSomethingUseful();
        }); 
}
1
xamarin.formsreactiveui

1 Answers

1
votes

Be explicit about the type argument of the Action and it will compile:

public LoginViewModel(IScreen hostScreen = null) : base(hostScreen)
{
    VerifyCallbackUrl = ReactiveCommand.Create(new Action<string>(xUrl => { DoSomethingUseful(); }));
}