122 lines
4.1 KiB
VB.net
122 lines
4.1 KiB
VB.net
#Region "Microsoft.VisualBasic::88599e270cb8b38339065a1d671ce31f, Microsoft.VisualBasic.Core\ApplicationServices\Parallel\Tasks\AsyncHandle.vb"
|
||
|
||
' Author:
|
||
'
|
||
' asuka (amethyst.asuka@gcmodeller.org)
|
||
' xie (genetics@smrucc.org)
|
||
' xieguigang (xie.guigang@live.com)
|
||
'
|
||
' Copyright (c) 2018 GPL3 Licensed
|
||
'
|
||
'
|
||
' GNU GENERAL PUBLIC LICENSE (GPL3)
|
||
'
|
||
'
|
||
' This program is free software: you can redistribute it and/or modify
|
||
' it under the terms of the GNU General Public License as published by
|
||
' the Free Software Foundation, either version 3 of the License, or
|
||
' (at your option) any later version.
|
||
'
|
||
' This program is distributed in the hope that it will be useful,
|
||
' but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
' MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
' GNU General Public License for more details.
|
||
'
|
||
' You should have received a copy of the GNU General Public License
|
||
' along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||
|
||
|
||
|
||
' /********************************************************************************/
|
||
|
||
' Summaries:
|
||
|
||
' Class AsyncHandle
|
||
'
|
||
' Properties: Handle, IsCompleted, Task
|
||
'
|
||
' Constructor: (+1 Overloads) Sub New
|
||
' Function: GetValue, Run
|
||
'
|
||
'
|
||
' /********************************************************************************/
|
||
|
||
#End Region
|
||
|
||
Namespace Parallel.Tasks
|
||
|
||
''' <summary>
|
||
''' Represents the status of an asynchronous operation.(背景线程加载数据)
|
||
''' </summary>
|
||
''' <typeparam name="TOut"></typeparam>
|
||
''' <remarks>
|
||
''' 这个后台任务模块是为了更加方便的构建出匿名方法的调用过程，因为这个对象的
|
||
''' 工作原理是基于匿名方法的``BeginInvoke``函数来工作的。
|
||
''' </remarks>
|
||
Public Class AsyncHandle(Of TOut)
|
||
|
||
''' <summary>
|
||
''' 封装一个方法，该方法不具有参数，且返回由<typeparamref name="TOut"></typeparamref>参数指定的类型的值。
|
||
''' </summary>
|
||
''' <returns></returns>
|
||
Public ReadOnly Property Task As Func(Of TOut)
|
||
''' <summary>
|
||
''' 对后台任务的访问
|
||
''' </summary>
|
||
''' <returns></returns>
|
||
Public ReadOnly Property Handle As IAsyncResult
|
||
|
||
''' <summary>
|
||
''' Gets a value that indicates whether the asynchronous operation has completed.
|
||
''' (获取一个值，该值指示异步操作是否已完成。)
|
||
''' </summary>
|
||
''' <returns></returns>
|
||
Public ReadOnly Property IsCompleted As Boolean
|
||
Get
|
||
If Handle Is Nothing Then
|
||
Return True
|
||
End If
|
||
|
||
Return Handle.IsCompleted
|
||
End Get
|
||
End Property
|
||
|
||
''' <summary>
|
||
''' Creates a new background task from a function handle.
|
||
''' </summary>
|
||
''' <param name="Task"></param>
|
||
Sub New(Task As Func(Of TOut))
|
||
Me.Task = Task
|
||
End Sub
|
||
|
||
''' <summary>
|
||
''' Start the background task thread.(启动后台背景线程)
|
||
''' </summary>
|
||
''' <returns></returns>
|
||
Public Function Run() As AsyncHandle(Of TOut)
|
||
If IsCompleted Then
|
||
_Handle = Task.BeginInvoke(Nothing, Nothing) ' 假若没有执行完毕也调用的话，会改变handle
|
||
End If
|
||
|
||
Return Me
|
||
End Function
|
||
|
||
''' <summary>
|
||
''' Current thread will be blocked at here if the background task not finished.
|
||
''' (没有完成的时候会一直在这里阻塞当前的线程)
|
||
''' </summary>
|
||
''' <returns></returns>
|
||
Public Function GetValue() As TOut
|
||
If Handle Is Nothing Then
|
||
Return _Task()
|
||
Else
|
||
Return Task.EndInvoke(Handle)
|
||
End If
|
||
End Function
|
||
|
||
Public Async Function GetValueAsyn() As Threading.Tasks.Task(Of TOut)
|
||
Return Await New Threading.Tasks.Task(Of TOut)(AddressOf GetValue)
|
||
End Function
|
||
End Class
|
||
End Namespace
|