取消冷可观测量 [英] Cancelling Cold Observables

问题描述

H

我的一个组件，提供了一种查询数据的RX方式。该方法的签名是：

One component of mine, offers a RX way to query data. the signature of the method is:

 

 

IObservable<TEntity> DataStore.Query<TEntity>(...) where TEntity is Entity

推荐答案

嗨Gentlehag，

Hi Gentlehag,

如果我错了，请纠正我，但是你的Observable。创建代码是同步的，这意味着在while循环结束之前不会返回一次性。

Correct me if I'm wrong, but your Observable.Create code is synchronous, meaning the disposable won't be returned until the while loop is finished.

正确吗？

Observables应该是异步的。如果您的数据访问层无法异步执行查询，您可以执行以下操作;

Observables are supposed to be asynchronous. If your data access layer has no means of executing a query asynchronously, you could do something like this;

（UNTESTED！）

(UNTESTED!)

Observable.Create<Entity>(observer =>
{
	var disposable = new CompositeDisposable();
	disposable.Add(Scheduler.NewThread.Schedule(() =>
	{
		IDataReader reader = null;
		//...Getting the DatAReader
		disposable.Add(reader);
		try
		{
			while (reader.Read())
			{
				entity = readertoEntity(reader);
				observer.OnNext(entity);
			}
			observer.OnCompleted();
		}
		catch(ObjectDisposedException)
		{
		}
		catch(Exception ex)
		{
			observer.OnError(ex);
		}		
	}));
	return disposable;
});

 

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