摘要:事件模式的非同步作業
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Public Class 事件模式的非同步作業
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Public Event AsnycCompleteEvent(ByVal sender As Object, ByVal e As WorkAsyncCompletedEventArgs)
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Public Sub StartWork()
07 Dim AsyncObj As System.ComponentModel.AsyncOperation = System.ComponentModel.AsyncOperationManager.CreateOperation(Nothing)
08 Dim WorkMethod As New DelWork(AddressOf MainWork)
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10 WorkMethod.BeginInvoke(New System.AsyncCallback(AddressOf Work_Complete), New Object() {WorkMethod, AsyncObj})
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End Sub
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13 Private Delegate Function DelWork() As Integer
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15 Private Function MainWork() As Integer
16 Dim Rand As New Random
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18 Threading.Thread.Sleep(10 * 1000)
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20 Return Rand.Next(0, 100)
21 End Function
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23 Private Sub Work_Complete(ByVal ar As IAsyncResult)
24 Dim UserObj() As Object = CType(ar.AsyncState, Object())
25 Dim WorkMethod As DelWork = UserObj(0)
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27 Dim AsyncObj As System.ComponentModel.AsyncOperation = CType(UserObj(1), System.ComponentModel.AsyncOperation)
28 Dim NewValue As Integer = WorkMethod.EndInvoke(ar)
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30 AsyncObj.PostOperationCompleted(New System.Threading.SendOrPostCallback(AddressOf Me.RaiseCompleteEvent), NewValue)
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32 End Sub
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34 Private Sub RaiseCompleteEvent(ByVal state As Object)
35 RaiseEvent AsnycCompleteEvent(Me, New WorkAsyncCompletedEventArgs(Nothing, False, CInt(state), Nothing))
36 End Sub
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38 Public Class WorkAsyncCompletedEventArgs
39 Inherits System.ComponentModel.AsyncCompletedEventArgs
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41 Sub New(ByVal err As Exception, ByVal Cancelled As Boolean, ByVal NewValue As Integer, ByVal userobj As Object)
42 MyBase.New(err, Cancelled, userobj)
43 Me._NewValue = NewValue
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End Sub
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46 Private _NewValue As Integer
47 Public ReadOnly Property NewValue() As Integer
48 Get
49 Return Me._NewValue
50 End Get
51 End Property
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53 End Class
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55End Class
Public Class 事件模式的非同步作業 02
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Public Event AsnycCompleteEvent(ByVal sender As Object, ByVal e As WorkAsyncCompletedEventArgs) 
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Public Sub StartWork() 
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Dim AsyncObj As System.ComponentModel.AsyncOperation = System.ComponentModel.AsyncOperationManager.CreateOperation(Nothing) 08
Dim WorkMethod As New DelWork(AddressOf MainWork) 09
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WorkMethod.BeginInvoke(New System.AsyncCallback(AddressOf Work_Complete), New Object() {WorkMethod, AsyncObj}) 11
End Sub 12
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Private Delegate Function DelWork() As Integer 14
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Private Function MainWork() As Integer 16
Dim Rand As New Random 17
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Threading.Thread.Sleep(10 * 1000) 19
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Return Rand.Next(0, 100) 21
End Function 22
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Private Sub Work_Complete(ByVal ar As IAsyncResult) 24
Dim UserObj() As Object = CType(ar.AsyncState, Object()) 25
Dim WorkMethod As DelWork = UserObj(0) 26
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Dim AsyncObj As System.ComponentModel.AsyncOperation = CType(UserObj(1), System.ComponentModel.AsyncOperation) 28
Dim NewValue As Integer = WorkMethod.EndInvoke(ar) 29
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AsyncObj.PostOperationCompleted(New System.Threading.SendOrPostCallback(AddressOf Me.RaiseCompleteEvent), NewValue) 31
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End Sub 33
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Private Sub RaiseCompleteEvent(ByVal state As Object) 35
RaiseEvent AsnycCompleteEvent(Me, New WorkAsyncCompletedEventArgs(Nothing, False, CInt(state), Nothing)) 36
End Sub 37
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Public Class WorkAsyncCompletedEventArgs 39
Inherits System.ComponentModel.AsyncCompletedEventArgs 40
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Sub New(ByVal err As Exception, ByVal Cancelled As Boolean, ByVal NewValue As Integer, ByVal userobj As Object) 42
MyBase.New(err, Cancelled, userobj) 43
Me._NewValue = NewValue 44
End Sub 45
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Private _NewValue As Integer 47
Public ReadOnly Property NewValue() As Integer 48
Get 49
Return Me._NewValue 50
End Get 51
End Property 52
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End Class 54
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End Class這裡的程式碼，可以直接COPY就可以使用。若不知用法歡迎提問。若有錯誤歡迎指正。
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