c#-5.0

问题 Consider the following to be extracts from a Windows 8 Metro / WinRT app, which have been reduced to the bare minimum required to show the anomaly: public class App : Application { public App() { UnhandledException += (sender, e) => e.Handled = true; } } public class MainPage : Page { private void Button_Click_1(object sender, RoutedEventArgs e) { throw new NotSupportedException(); } private async void Button_Click_2(object sender, RoutedEventArgs e) { throw new NotSupportedException(); } }

问题 I am trying to learn/understand more about async/await in C# and I would put myself in rookie category so all your comments/suggestions are welcome. I wrote small test to have better understanding and clarification about await/async. My program freezes after "GetStringLength" call I tried reading several things but looks like I am stuck and I thought of taking expert opinion on what I might be doing wrong. Can you please guide me or point me in right direction here? using System; using System

问题 Hi I am on trial with twilio. I have seen this link: https://www.twilio.com/help/faq/twilio-basics/how-does-twilios-free-trial-work It says "You must verify a phone number before you can send SMS messages to it from your trial phone number." And also restricts on the outgoing text But what if I just want to verfiy the number, using: var twilio = new TwilioRestClient( Keys.TwilioSid, Keys.TwilioToken ); var result = twilio.SendMessage( Keys.FromPhone, message.Destination, message.Body); //

问题 New to async await integration in C# 5. I'm working with some basic Task based methods to explore async await and the TPL. In this example below I'm calling a web service with a timeout of 5 seconds. If the timeout expires it should throw an exception so I can return false from the method. However, the timeout never occurs, or maybe it does but the Task never returns. public static Task<bool> IsConnectedAsync() { return Task.Run(() => { try { using (WSAppService.AppService svc = new

问题 I must implement an ObservableHashSet<T> that can quickly ( O(1) ) test for object existence: public class ObservableHashSet<T> : ObservableCollection<T>{ readonly ISet<T> _set = new HashSet<T>(); protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e){ base.OnCollectionChanged(e); if (e.Action == NotifyCollectionChangedAction.Move) return; if (e.OldItems != null) foreach (var old in e.OldItems.Cast<T>()) _set.Remove(old.GetHashable()); if (e.NewItems == null) return;

问题 I just saw on the Async CTP website that the next version of VB.NET will have iterators. I guess they included iterators because the rewriting process is similar to the one used for the new async / await feature. But reading the document that explains the feature, I realized that VB.NET iterators will actually have features that are not available in C# today, namely: iterator blocks in a try/catch block anonymous iterator blocks These were known limitations in C#. Is there any chance that

问题 I have found example of async using of XmlWriter within msdn documentation http://msdn.microsoft.com/en-us/library/system.xml.xmlwriter.aspx async Task TestWriter(Stream stream) { XmlWriterSettings settings = new XmlWriterSettings(); settings.Async = true; using (XmlWriter writer = XmlWriter.Create(stream, settings)) { await writer.WriteStartElementAsync("pf", "root", "http://ns"); await writer.WriteStartElementAsync(null, "sub", null); await writer.WriteAttributeStringAsync(null, "att", null

问题 I am new to async and await style of programming. How can I solve the following problem: I am calling the below code first. The problem here is that the first line is awaiting which need to populate the categoriesvm.Categorieslist , which it does not, but the second line is called. (which I think is the default behaviour of await) How can I make sure that the second line is called only when the categoriesvm.Categorieslist is populated in the first line? protected override void OnNavigatedTo

问题 I'm implementing a set of RESTful services for some developments and one of these is an authentication service . This authentication service authenticates two kinds of identities: Applications . AppKey-based authentication so clients must register for a key in order to access to the rest of the services . Users . Well-known credentials (user+password)-based user authentication so humans and machines can work with these RESTful services through client applications. These RESTful services are

问题 Let say I have an async method: public async Task Do() { await Task.Delay(1000); } Another method is trying to call Do method inside catch block public async Task DoMore() { try { } catch (Exception) { await Do(); //compiled error. } } But this way, the compiler does not allow using await inside catch , is there any reason behind the scene why we could not use it that way? 回答1: Update This will be supported in C# 6. It turned out that it wasn't fundamentally impossible, and the team worked