vb.net多线程简单示例

主线程中的代码

 

            Dim delegate1 As B3D4D69AF0E1DB8A7B7EE6FDelegate
            delegate1 = AddressOf B3D4D69AF0E1DB8A7B7EE6F
            Dim ar As System.IAsyncResult
            Dim param(2) As Object
            param(0) = Me
            param(1) = delegate1
            ar = delegate1.BeginInvoke(resStr, CallBackB3D4D69AF0E1DB8A7B7EE6FDelegate, param)

 

耗时的操作代码

    Private Function B3D4D69AF0E1DB8A7B7EE6F(ByVal D7B89BE7F84108A1EF3ED31124D049() As String) As DataSet
        Dim result As DataSet = Nothing
        Try
            Dim ws As New SRL.F408C4CE284F489C7B22E2461FE4BFSoapClient()
            result = ws.E13F1B91BD3546FA93DC9F0B8CD56B7B(D7B89BE7F84108A1EF3ED31124D049) ‘web service访问，此操作很耗时
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
        Return result
    End Function
    Delegate Function B3D4D69AF0E1DB8A7B7EE6FDelegate(ByVal D7B89BE7F84108A1EF3ED31124D049() As String) As DataSet ‘一定要定义，否则会出错

 

callback处理，上面的函数是返回dataset，所以这里线程结束后也是获取dataset

    Private CallBackB3D4D69AF0E1DB8A7B7EE6FDelegate As AsyncCallback = AddressOf CallBackB3D4D69AF0E1DB8A7B7EE6F
    Sub CallBackB3D4D69AF0E1DB8A7B7EE6F(ByVal ar As IAsyncResult)
        Try
            Dim delegate1 As B3D4D69AF0E1DB8A7B7EE6FDelegate = ar.AsyncState(1)
            Dim r As DataSet = delegate1.EndInvoke(ar) '获取ws结果，然后操作这个结果
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub