MailboxProcessor.Start<'Msg> 方法 (F#)
建立並啟動代理程式。
命名空間/模組路徑:Microsoft.FSharp.Control
組件:FSharp.Core (在 FSharp.Core.dll 中)
// Signature:
static member Start : (MailboxProcessor<'Msg> -> Async<unit>) * ?CancellationToken -> MailboxProcessor<'Msg>
// Usage:
MailboxProcessor.Start (body)
MailboxProcessor.Start (body, cancellationToken = cancellationToken)
參數
body
型別:MailboxProcessor<'Msg> -> Async<unit>產生非同步計算的函式,而在呼叫 Start 時,非同步計算會執行為 MailboxProcessor 的讀取迴圈。
cancellationToken
型別:CancellationTokenbody 的選擇性取消語彙基元。預設是 Async.DefaultCancellationToken.
傳回值
建立的 MailboxProcessor。
備註
body 函式會用來產生由代理程式執行的非同步計算。
範例
下列程式碼範例示範如何啟動信箱處理器代理程式。在此範例中,主控台輸入的每一行將被發送到訊息佇列中。程式會讀取每個訊息,並使用回覆通道回覆。當收到「停止」訊息時,就會傳送停止回覆並結束程式。
open System
type Message = string * AsyncReplyChannel<string>
let formatString = "Message number {0} was received. Message contents: {1}"
let printThreadId note =
// Append the thread ID.
printfn "%d : %s" System.Threading.Thread.CurrentThread.ManagedThreadId note
let agent = MailboxProcessor<Message>.Start(fun inbox ->
let rec loop n =
async {
let! (message, replyChannel) = inbox.Receive();
printThreadId "MailboxProcessor"
if (message = "Stop") then
replyChannel.Reply("Stopping.")
else
replyChannel.Reply(String.Format(formatString, n, message))
do! loop (n + 1)
}
loop 0)
printfn "Mailbox Processor Test"
printfn "Type some text and press Enter to submit a message."
printfn "Type 'Stop' to close the program."
let rec loop() =
printf "> "
let input = Console.ReadLine()
printThreadId("Console loop")
let reply = agent.PostAndReply(fun replyChannel -> input, replyChannel)
if (reply <> "Stopping.") then
printfn "Reply: %s" reply
loop()
else
()
loop()
printfn "Press Enter to continue."
Console.ReadLine() |> ignore
下列為範例工作階段。
平台
Windows 8 中, Windows 7, Windows Server 2012 上, Windows Server 2008 R2
版本資訊
F# 核心程式庫版本
支援版本:2.0, 4.0,可攜式執行檔 (PE)。