MailboxProcessor.PostAndAsyncReply<'Msg,'Reply> 方法 (F#)
以异步方式将消息发送到代理并等待通道答复。
命名空间/模块路径： Microsoft.FSharp.Control
程序集：FSharp.Core（在 FSharp.Core.dll 中）
// Signature:
member this.PostAndAsyncReply : (AsyncReplyChannel<'Reply> -> 'Msg) * ?int -> Async<'Reply>
// Usage:
mailboxProcessor.PostAndAsyncReply (buildMessage)
mailboxProcessor.PostAndAsyncReply (buildMessage, timeout = timeout)
参数
buildMessage
类型：AsyncReplyChannel<'Reply> -> 'Msg要将 AsyncReplyChannel 并入要发送的消息的函数。
timeout
类型：int用于等待答复消息的可选超时参数（以毫秒为单位）。默认值为 -1，对应于 Infinite。
返回值
将等待来自代理的答复的异步计算（Async 对象）。
备注
通过将 buildMessage 应用于将并入消息的新答复通道，将生成消息。接收代理必须处理此消息并在此答复通道上正好调用一次 Reply 方法。
示例
以下代码示例显示一个邮箱处理器代理，使用PostAndAsyncReply。PostAndAsyncReply 的返回值是一个异步的工作流，在本例中以 Async.StartWithContinuations 开始来设置处理答复的代码。
open System
type Message = string * AsyncReplyChannel<string>
let formatString = "Message number {0} was received. Message contents: {1}"
let agent = MailboxProcessor<Message>.Start(fun inbox ->
let rec loop n =
async {
let! (message, replyChannel) = inbox.Receive();
// Delay so that the responses come in a different order.
do! Async.Sleep( 5000 - 1000 * n);
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."
let isCompleted = false
while (not isCompleted) do
printf "> "
let input = Console.ReadLine()
let messageAsync = agent.PostAndAsyncReply(fun replyChannel -> input, replyChannel)
// Set up a continuation function (the first argument below) that prints the reply.
// The second argument is the exception continuation (not used).
// The third argument is the cancellation continuation (not used).
Async.StartWithContinuations(messageAsync,
(fun reply -> printfn "%s" reply),
(fun _ -> ()),
(fun _ -> ()))
printfn "Press Enter to continue."
Console.ReadLine() |> ignore
下面是为示例部分。输出可能交错，显示消息处理函数在多个线程上运行。
平台
Windows 8，Windows 7，Windows server 2012中，Windows server 2008 R2
版本信息
F#核心库版本
支持:2.0，4.0，可移植