取消reactivex.net中的任务

假设我已经存在如下代码：

public IEnumerable<DataType> GetAllData(string[] ids) {
    foreach(var id in ids) {
        //this is a time-consuming operation, like query from database
        var data = this.repo.Find(id);
        yield return data;
    }
}

我尝试将Rx应用于前端代码：

var observable = GetAllData(new[] { "1", "2", "3" }).ToObservable();
var subs = observable
    .SubscribeOn(Scheduler.Default)
    .Subscribe(
        data => Console.WriteLine(data.Id), 
        () => Console.WriteLine("All Data Fetched Completed"));

它工作正常。

但是，一旦我将订阅绑定到IObservable，有什么方法可以阻止它中途继续获取数据吗？处置订阅不会停止枚举。

var cts = new CancellationTokenSource();
var observable = GetAllData(new[] { "1", "2", "3" }).ToObservable().TakeWhile(x => !cts.IsCancellationRequested);
var subs = observable
    .SubscribeOn(Scheduler.Default)
    .Subscribe(
        data => Console.WriteLine(data.Id), 
        () => Console.WriteLine("All Data Fetched Completed"));
//...
cts.Cancel();