How to attach CancellationTokenSource to DownloadStringTaskAsync method and cancel the async call?

Question

I an creating a sample example to call link using WebClient using async and await method now I want to attach cancel async call functionality also. But I am not able to get Can

Answer 1

Extension methods based on svick's answer:

public static async Task DownloadStringTaskAsync(this WebClient webClient, string url, CancellationToken cancellationToken) {
    using (cancellationToken.Register(webClient.CancelAsync)) {
        return await webClient.DownloadStringTaskAsync(url);
    }
}

public static async Task DownloadStringTaskAsync(this WebClient webClient, Uri uri, CancellationToken cancellationToken) {
    using (cancellationToken.Register(webClient.CancelAsync)) {
        return await webClient.DownloadStringTaskAsync(uri);
    }
}