Async implementation of IValueConverter

Question

I have an asynchronous method which I want to trigger inside an IValueConverter.

Is there a better way than forcing it to be synchronous by calling the

Answer 1

The alternative approach is to make your own control which supports async sources or data.

Here is the example with the image

    public class AsyncSourceCachedImage : CachedImage
{
    public static BindableProperty AsyncSourceProperty = BindableProperty.Create(nameof(AsyncSource), typeof(Task), typeof(AsyncSourceSvgCachedImage), null, propertyChanged: SourceAsyncPropertyChanged);

    public Task AsyncSource
    {
        get { return (Task)GetValue(AsyncSourceProperty); }
        set { SetValue(AsyncSourceProperty, value); }
    }

    private static async void SourceAsyncPropertyChanged(BindableObject bindable, object oldColor, object newColor)
    {
        var view = bindable as AsyncSourceCachedImage;
        var taskForImageSource = newColor as Task;

        if (taskForImageSource != null)
        {
            var awaitedImageSource = await taskForImageSource;

            view.Source = awaitedImageSource;
        }
    }
}

Moreover, you might implement the loading activity indicator over the image until the task will be resolved.