C# IReactiveCommand.ExecuteAsync方法代码示例

        private static async Task AssertThrowsOnExecuteAsync(IReactiveCommand<Unit> command, Exception exception)
        {
            command.ThrownExceptions.Subscribe();

            var failed = false;

            try
            {
                await command.ExecuteAsync();
            }
            catch (Exception ex)
            {
                failed = ex == exception;
            }

            Assert.True(failed);
        }

        /// <summary>
        /// Setup the lookup logic, and use the interface to do the web call.
        /// </summary>
        /// <param name="caller"></param>
        public WebCallViewModel(IWebCaller caller)
        {
            // Do a search when nothing new has been entered for 800 ms and it isn't
            // an empty string... and don't search for the same thing twice.

            var newSearchNeeded = this.WhenAny(p => p.InputText, x => x.Value)
                .Throttle(TimeSpan.FromMilliseconds(800), RxApp.TaskpoolScheduler)
                .DistinctUntilChanged()
                .Where(x => !string.IsNullOrWhiteSpace(x));

            _doWebCall = ReactiveCommand.CreateAsyncObservable(x => caller.GetResult(x as string));

            newSearchNeeded.InvokeCommand(_doWebCall);

            // Run the web call and save the results back to the UI when done.
            var webResults =
                _doWebCall.ExecuteAsync();

            // The results are stuffed into the property, on the proper thread
            // (ToProperty takes care of that) when done. We never want the property to
            // be null, so we give it an initial value of "".
            webResults
                .ToProperty(this, x => x.ResultText, out _ResultTextOAPH, "");
        }

        private static async Task assertExceptionForwardedToThrownExceptions(IReactiveCommand<Unit> command, Exception exception)
        {
            var exceptions = command.ThrownExceptions.CreateCollection();

            await command.ExecuteAsync()
                         .Catch(Observable.Empty<Unit>())
                         .DefaultIfEmpty(Unit.Default);

            Assert.Equal(1, exceptions.Count);
            Assert.Contains(exception, exceptions);
        }