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Async.FromBeginEnd<'T> 方法 (F#)

更新:2010 年 7 月

在 CLI API 內使用的樣式中,建立關於 Begin/End 動作組的非同步計算。

命名空間/模組路徑: Microsoft.FSharp.Control

組件:FSharp.Core (在 FSharp.Core.dll 中)

// Signature:
static member FromBeginEnd : (AsyncCallback * obj -> IAsyncResult) * (IAsyncResult -> 'T) * ?(unit -> unit) -> Async<'T>

// Usage:
Async.FromBeginEnd (beginAction, endAction)
Async.FromBeginEnd (beginAction, endAction, cancelAction = cancelAction)

參數

  • beginAction
    型別:AsyncCallback * obj -> IAsyncResult

    會起始傳統 CLI 非同步作業的函式。

  • endAction
    型別:IAsyncResult -> 'T

    會完成傳統 CLI 非同步作業的函式。

  • cancelAction
    型別:(unit -> unit)

    取消作業的要求提出後要執行的選擇性函式。

傳回值

用於包裝指定之 Begin/End 函式的非同步計算。

備註

就例如下列程式碼會建立包裝 Web 服務呼叫的非同步計算。

Async.FromBeginEnd(ws.BeginGetWeather,ws.EndGetWeather)

當計算執行時, beginFunc執行的回呼,用來表示註解的接續的 計算。 叫用回呼時,會使用 endFunc 擷取整體結果。

計算會在等待作業完成期間回應取消。 如果發生取消而且已指定 cancelAction,便會執行取消作業,而且計算作業會繼續等待作業完成。 如果 cancelAction未指定,取消通知會造成立即,停止計算,而且後續的引動過程的回呼會被忽略

範例

下列程式碼範例會示範如何建立一個 F # 非同步計算從使用開始/結束模式的.NET 非同步 API。 此範例使用.NET 通訊端 API, System.Net.Sockets 它會實作簡單的伺服器應用程式接受連線,從一個的伺服器接收資料,然後傳送回應。

module SocketClient =

    open System.Net
    open System.Net.Sockets
    open System.Collections.Generic

    let toIList<'T> (data : 'T array) =
        let segment = new System.ArraySegment<'T>(data)
        let data = new List<System.ArraySegment<'T>>() :> IList<System.ArraySegment<'T>>
        data.Add(segment)
        data

    type Socket with
        member this.MyAcceptAsync(receiveSize) =
            Async.FromBeginEnd(receiveSize,
                               (fun (receiveSize, callback, state) -> this.BeginAccept(receiveSize, callback, state)),
                               this.EndConnect)
        member this.MyConnectAsync(ipAddress : IPAddress, port : int) =
            Async.FromBeginEnd(ipAddress, port,
                               (fun (ipAddress:IPAddress, port, callback, state) -> this.BeginConnect(ipAddress, port, callback, state)),
                               this.EndConnect)
        member this.MySendAsync(data, flags : SocketFlags) =
            Async.FromBeginEnd(toIList data, flags, 
                               (fun (data : IList<System.ArraySegment<byte>>, flags : SocketFlags, callback, state) -> this.BeginSend(data, flags, callback, state)),
                               this.EndSend)
        member this.MyReceiveAsync(data, flags : SocketFlags) =
            Async.FromBeginEnd(toIList data, flags, 
                               (fun (data : IList<System.ArraySegment<byte>>, flags : SocketFlags, callback, state) -> this.BeginReceive(data, flags, callback, state)),
                               this.EndReceive)

    let port = 11000

    let socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
    let ipHostEntry = Dns.Resolve("hostname.contoso.com")
    printfn "Server address: %s" (ipHostEntry.AddressList.[0].ToString())

    let connectSendReceive (socket : Socket) =
        async {
            do! socket.MyConnectAsync(ipHostEntry.AddressList.[0], 11000)
            printfn "Connected to remote host."
            let buffer1 = [| 0uy .. 255uy |]
            let buffer2 = Array.zeroCreate<byte> 255
            let flags = new SocketFlags()
            printfn "Sending data..."
            let! flag = socket.MySendAsync(buffer1, flags)
            printfn "Receiving data..."
            let! result = socket.MyReceiveAsync(buffer2, flags)
            printfn "Received data from remote host."
            return buffer2
        }

    let acceptReceiveSend (socket : Socket) =
        async {
            socket.Listen(1)
            do! socket.MyAcceptAsync(256)
            let buffer1 = Array.zeroCreate<byte> 255
            let flags = new SocketFlags()
            let! flag = socket.MyReceiveAsync(buffer1, flags)
            let buffer2 = Array.rev buffer1
            let! flag = socket.MySendAsync(buffer2, flags)
            return buffer2
        }

    let taskClient = Async.StartAsTask(connectSendReceive(socket))

    taskClient.Wait()
    taskClient.Result |> Array.iter (fun elem -> printf "%d " elem)
              

下列程式碼範例會顯示與伺服器程式碼,在先前的範例中可以使用用戶端程式碼。

module SocketServer =

    open System.Net
    open System.Net.Sockets
    open System.Collections.Generic

    let toIList<'T> (data : 'T array) =
        let segment = new System.ArraySegment<'T>(data)
        let data = new List<System.ArraySegment<'T>>() :> IList<System.ArraySegment<'T>>
        data.Add(segment)
        data

    type Socket with
        member this.MyAcceptAsync() =
            Async.FromBeginEnd((fun (callback, state) -> this.BeginAccept(callback, state)),
                               this.EndAccept)
        member this.MyConnectAsync(ipAddress : IPAddress, port : int) =
            Async.FromBeginEnd(ipAddress, port,
                               (fun (ipAddress:IPAddress, port, callback, state) ->
                                   this.BeginConnect(ipAddress, port, callback, state)),
                               this.EndConnect)
        member this.MySendAsync(data : byte array, flags : SocketFlags) =
            Async.FromBeginEnd(toIList data, flags, 
                               (fun (data : IList<System.ArraySegment<byte>>,
                                     flags : SocketFlags, callback, state) ->
                                         this.BeginSend(data, flags, callback, state)),
                               this.EndSend)
        member this.MyReceiveAsync(data : byte array, flags : SocketFlags) =
            Async.FromBeginEnd(toIList data, flags, 
                               (fun (data : IList<System.ArraySegment<byte>>,
                                     flags : SocketFlags, callback, state) ->
                                         this.BeginReceive(data, flags, callback, state)),
                               this.EndReceive)

    let port = 11000

    let socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
    let ipHostInfo = Dns.Resolve(Dns.GetHostName())
    let localIPAddress = ipHostInfo.AddressList.[0]
    let localEndPoint = new IPEndPoint(localIPAddress, port)
    socket.Bind(localEndPoint)


    let connectSendReceive (socket : Socket) =
        async {
            do! socket.MyConnectAsync(ipHostInfo.AddressList.[0], 11000)
            let buffer1 = [| 0uy .. 255uy |]
            let buffer2 = Array.zeroCreate<byte> 255
            let flags = new SocketFlags()
            let! flag = socket.MySendAsync(buffer1, flags)
            let! result = socket.MyReceiveAsync(buffer2, flags)
            return buffer2
        }

    let acceptReceiveSend (socket : Socket) =
        async {
            printfn "Listening..."
            socket.Listen(10)
            printfn "Accepting..."
            let! socket = socket.MyAcceptAsync()

            let buffer1 = Array.zeroCreate<byte> 256
            let flags = new SocketFlags()
            printfn "Receiving..."
            let! nBytes = socket.MyReceiveAsync(buffer1, flags)
            printfn "Received %d bytes from client computer." nBytes
            let buffer2 = Array.rev buffer1
            printfn "Sending..."
            let! flag = socket.MySendAsync(buffer2, flags)
            printfn "Completed."
            return buffer2
        }

    let taskServer = Async.StartAsTask(acceptReceiveSend(socket))    
    taskServer.Wait()
    socket.Close()

範例輸出

            

平台

Windows 7、Windows Vista SP2、Windows XP SP3、Windows XP x64 SP2、Windows Server 2008 R2、Windows Server 2008 SP2、Windows Server 2003 SP2

版本資訊

F# 執行階段

支援版本:2.0、4.0

Silverlight

支援版本:3

請參閱

參考

Control.Async 類別 (F#)

Microsoft.FSharp.Control 命名空間 (F#)

變更記錄

日期

History

原因

2010 年 7 月

加入程式碼範例。

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