cancellation_token_source fileTaskTokenSource;

// Cancel button event handler:
fileTaskTokenSource.cancel();

// task chain

StorageFolder^ documentsFolder = KnownFolders::DocumentsLibrary;
    task<StorageFile^> getFileTask(documentsFolder->GetFileAsync(fileName));

getFileTask.then([](StorageFile^ storageFileSample) {       
        return storageFileSample->DeleteAsync();
    }).then([](task<void> t) {

try
        {
            t.get();

// .get() didn't throw, so we succeeded.
            OutputDebugString(L"File deleted.");
        }
        catch (Exception^ e)
        {
                 //Example output: The system cannot find the specified file.
                 OutputDebugString(e->Message->Data());
        }

IAsyncOperation<T>^ asyncOperation = create_async( []() {
    return create_task(FirstAsync(...))
    .then( [](X val){
        return SecondAsync(val, ...);
    }).then( [](Y val)
        return ThirdAsync(val, ...);
    });

IAsyncOperationWithProgress<int,String^>^ TestWithProgressAsync(int input)
{
    return create_async([input](progress_reporter<String^> reporter) {
        if(input==0)
             throw ref new InvalidArgumentException();
        bool moreToDo = true;
        while (moreToDo)
        {
            // Check for cancellation.
            if (is_task_cancellation_requested()) {                
                // Cancel the current task.
                cancel_current_task();
                return 32;
                moreToDo = false;
            }
            else {
                // Perform work.
                reporter.report("Running");
            }
        }
        reporter.report("Finished");
        return 42;
    });

cancellation_token_source TaskTokenSource;
        task<int> t;

// In BlankPage.xaml.cpp

BlankPage::BlankPage()
{
    InitializeComponent();
    // TestWithProgressAsync(0) will throw a execption
    t=task<int>(TestWithProgressAsync(1),TaskTokenSource.get_token());
}

c+=res;

safe_cast<TextBlock^>(this->FindName("result"))->Text+=res;
        }catch(Exception^ ex)
        {
            safe_cast<TextBlock^>(this->FindName("result"))->Text+=ref new String(ex->Message->Data());
        }
    },task_continuation_context::use_arbitrary());
}

{
    InitializeComponent();
    // TestWithProgressAsync(0) will throw a execption
    AsyncOper=TestWithProgressAsync(0);

AsyncOper->Progress=ref new AsyncOperationProgressHandler<int,String^>(
        [this](IAsyncOperationWithProgress<int,String^>^ pretask,  String^ progressInfo){
            safe_cast<TextBlock^>(this->FindName("result"))->Text+=progressInfo+"\n";

});

AsyncOper->Completed=ref new AsyncOperationWithProgressCompletedHandler<int,String^>(
        [this](IAsyncOperationWithProgress<int,String^>^ pretask, AsyncStatus asyncStatus){
            if(asyncStatus==AsyncStatus::Completed)
            {
                int res=pretask->GetResults();
            }
            if(asyncStatus==AsyncStatus::Canceled)
            {
                safe_cast<TextBlock^>(this->FindName("result"))->Text="Cancel";
            }
            if(asyncStatus==AsyncStatus::Error)
            {
                try
                {
                    int res=pretask->GetResults();

}catch(Exception^ ex)
                {
                    safe_cast<TextBlock^>(this->FindName("result"))->Text+=ref new String(ex->Message->Data());
                }
            }
    });
}

void Application3::BlankPage::Button_Click_Cancel(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
    AsyncOper->Cancel();
}