异步实例

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Delegate Function InsertDataListDelegate() As Boolean
    Delegate Sub FlashControllerDelegate(ByVal i As Integer)

    Dim instanceDelegate As InsertDataListDelegate = AddressOf InsertDataList

    Public Function InsertDataList() As Boolean
        Dim i As Long
        'Throw New Exception("fff")
        For i = 1 To 9999
            FlashController(i)
        Next
        MsgBox("OVER")
    End Function

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim ar As System.IAsyncResult
        ar = instanceDelegate.BeginInvoke(CallBackDelegate, Nothing)
    End Sub

    Public Sub FlashController(ByVal i As Integer)
        If Me.InvokeRequired Then
            Invoke(New FlashControllerDelegate(AddressOf FlashController), i)
            Return
        End If
        ComboBox1.Items.Add(i)
    End Sub

    '回调函数的参数
    Dim myValue As Integer = 10
    '回调函数的定义
    Sub PutToDesk(ByVal ar As IAsyncResult)
        Console.WriteLine(ar.IsCompleted) '拿到参数
        '相应的操作
    End Sub

    Private CallBackDelegate As AsyncCallback = AddressOf PutToDesk

End Class