Is it possible to interrupt an asynchronous function executed via async?

Asynchronous functions launched via async cannot simply be 'interrupted' or 'stopped' from outside on their own, as they do not support forced cancellation.

To manage cancellation of asynchronous operations in Android (and generally in C#), the CancellationToken mechanism is used.

How it works:

• An object of CancellationToken is passed to the function.
• Inside the function, the token's state is periodically checked (for example, token.IsCancellationRequested).
• If cancellation is requested, the function terminates correctly, throwing an OperationCanceledException or simply returning a result.

Example:

async Task DoWorkAsync(CancellationToken token)
{
    for(int i = 0; i < 100; i++)
    {
        token.ThrowIfCancellationRequested();
        await Task.Delay(100); // simulate work
    }
}

// Usage
var cts = new CancellationTokenSource();
var task = DoWorkAsync(cts.Token);
// To cancel:
cts.Cancel();

Thus, cancellation is a cooperative process, and the function must be written with support for CancellationToken.