c# - Async Task to Youtube -

i'm new actually. have short application check whether application can authentication asynchronously youtube , return application it's track. here snippet of code

private async void button1_click(object sender, routedeventargs e) {     await youtubeauth();      messagebox.show(token); }  private async task youtubeauth() {     oauth2credential = await googlewebauthorizationbroker.authorizeasync(         new clientsecrets { clientid = youtubeclientid, clientsecret = youtubeclientsecret },         // oauth 2.0 access scope allows application upload files         // authenticated user's youtube channel, doesn't allow other types of access.         new[] { youtubeservice.scope.youtubeupload },         "user",         cancellationtoken.none     );      token = oauth2credential.token.tokentype; } 

the code messagebox.show(token); never been executed.

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edit:

i have tried other simpler code below , still messagebox never triggered

private async void button1_click(object sender, routedeventargs e) {     await youtubeauth();      messagebox.show(token); }  private async task youtubeauth() {     token = "test token"; } 

this seems interesting. have written fastly wpf example app verify

mainwindow.xaml

<window x:class="testasynctasktoyoutube.mainwindow"         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"         xmlns:local="clr-namespace:testasynctasktoyoutube"         mc:ignorable="d"         title="mainwindow" height="350" width="525">     <grid>         <button x:name="button" content="button" />     </grid> </window> 

mainwindow.xaml.cs

using system.threading.tasks; using system.windows;  namespace testasynctasktoyoutube {     public partial class mainwindow : window     {         private string token;          public mainwindow()         {             initializecomponent();             button.click += button_click;         }          private async void button_click(object sender, routedeventargs e)         {             await youtubeauth();             messagebox.show(token);         }          private task<int> youtubeauth()         {             token = "test token";             return task.fromresult(0);         }     } } 

no problems here. messagebutton fires should be. sure code bit different mine anywhere :|

how can you?

edit: avoiding task.fromresult() (.net 4.5 feature)

private async task youtubeauth() {     token = "test token"; }