增加事件捕捉和放弃事件捕捉的实例

效果图：

点击了"新增事件"后，当输入框的数值发生变动时，自动激发事件

点击了"删除事件"后，当输入框的数值发生变动时，无激发事件

代码如下：

乐博网lob.cn提示：调试环境为 vs2005 +  windows2003 / windows2008 / xp / vista + .NET Framework 2.0

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        '更多.net源码和教程，来自[乐博网 www.lob.cn]
    End Sub

    Public Sub MyButtonClick(ByVal sender As System.Object, ByVal e As System.EventArgs)
        lblAns.Text = (Val(txtN1.Text) + Val(txtN2.Text)).ToString
    End Sub

    Private Sub btnAdd_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnAdd.Click
        AddHandler txtN1.TextChanged, AddressOf MyButtonClick
        AddHandler txtN2.TextChanged, AddressOf MyButtonClick
    End Sub

    Private Sub btnDel_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnDel.Click
        RemoveHandler txtN1.TextChanged, AddressOf MyButtonClick
        RemoveHandler txtN2.TextChanged, AddressOf MyButtonClick
    End Sub

End Class