F＃方法指針

Question

上市Script.fsx「不是從這個代碼位置訪問」：

#load "AccountDetails.fs" 
#r @"..\packages\FSharpx.Core.1.4.120207\lib\FSharpx.Async.dll" 
#r @"C:\Program Files\Windows Azure SDK\v1.6\ServiceBus\ref\Microsoft.ServiceBus.dll" 
#load "AzureServiceBus.fs" 

open AccountDetails 
open FSharp.Control 

open Microsoft.ServiceBus 
open Microsoft.ServiceBus.Messaging 

// Let's do some service bus hacking 
let tp = TokenProvider.CreateSharedSecretTokenProvider(issuer_name, key) 
let asb_uri = ServiceBusEnvironment.CreateServiceUri("sb", ns, "") 
let mf = MessagingFactory.Create(asb_uri, tp) 
let nm = NamespaceManager(asb_uri, NamespaceManagerSettings(TokenProvider = tp)) 

module Queue = 
    let queueDescription name = async { 
    let! exists = Async.FromBeginEnd(name, nm.BeginQueueExists, nm.EndQueueExists) 
    return! if exists then Async.FromBeginEnd(name, nm.BeginGetQueue, nm.EndGetQueue) 
      else Async.FromBeginEnd(name, nm.BeginCreateQueue, nm.EndCreateQueue) 
    } 

和我得到這個錯誤：Script.fsx(22,43): error FS0503: The member or object constructor 'BeginCreateQueue' taking 3 arguments are not accessible from this code location. All accessible versions of method 'BeginCreateQueue' take 3 arguments.

因此它告訴我，有3個參數的方法是不可訪問，但有3個參數的可訪問版本？

Answer 1

BeginCreateQueue有兩個公共過載。我的猜測是類型推理很難猜測你想要哪一個。嘗試添加類型註釋：

Async.FromBeginEnd(name, 
    nm.BeginCreateQueue : string * AsyncCallback * obj -> IAsyncResult, 
    nm.EndCreateQueue) 

如果這不是你想要的過載，嘗試string代QueueDescription。