好像最好答案是使用Observable.CreateWithDisposable()
例如
public IObservable<XElement> GetReport(string reportName)
{
return from client in Observable.Return(new WebServiceClient())
from completed in Observable.CreateWithDisposable<GetReportDataCompletedEventArgs>(observer =>
{
var subscription = Observable.FromEvent<GetReportDataCompletedEventArgs>(client, "GetReportDataCompleted")
.Take(1)
.Select(e => e.EventArgs)
.Subscribe(observer);
client.GetReportDataAsync(reportName);
return subscription;
})
from close in this.CloseClient(client)
select completed.Result;
}
爲了更方便與我重構了CreateWithDisposable成可以用我所有的Web服務調用,包括事件參數類型自動確定事件的名稱使用的公共功能的工作:
private IObservable<T> CallService<T>(ICommunicationObject serviceClient, Action start) where T : AsyncCompletedEventArgs
{
if (typeof(T) == typeof(AsyncCompletedEventArgs))
{
throw new InvalidOperationException("Event arguments type cannot be used to determine event name, use event name overload instead.");
}
string completedEventName = typeof(T).Name.TrimEnd("EventArgs");
return CallService<T>(serviceClient, start, completedEventName);
}
private IObservable<T> CallService<T>(ICommunicationObject serviceClient, Action start, string completedEventName) where T : AsyncCompletedEventArgs
{
return Observable.CreateWithDisposable<T>(observer =>
{
var subscription = Observable.FromEvent<T>(serviceClient, completedEventName).Take(1).Select(e => e.EventArgs).Subscribe(observer);
start();
return subscription;
});
}
// Example usage:
public IObservable<XElement> GetReport(string reportName)
{
return from client in Observable.Return(new WebServiceClient())
from completed in this.CallService<GetReportDataCompletedEventArgs>(client,() => client.GetReportDataAsync(reportName))
from close in this.CloseClient(client)
select completed.Result;
}
/// <summary>
/// Asynchronously closes the web service client
/// </summary>
/// <param name="client">The web service client to be closed.</param>
/// <returns>Returns a cold observable sequence of a single success Unit.</returns>
private IObservable<AsyncCompletedEventArgs> CloseClient(WebServiceClient client)
{
return this.CallService<AsyncCompletedEventArgs>(client, client.CloseAsync, "CloseCompleted");
}
希望這可以幫助別人!
看起來不是很簡單給我嗎? – AnthonyWJones 2010-09-27 12:24:08
相信我,當你使用它。調用它只是service.GetReport(「MyReport1」)。訂閱(this.LoadResults); – 2010-09-27 23:55:26