addhanderl与handels区别

遇到一个问题。addhandler 与 handels的区别是什么

举例：如下语句运行成功

 Private Sub 供货商IDSearchLookUpEdit_TextChanged(sender As Object, e As EventArgs) Handles 供货商IDSearchLookUpEdit.TextChanged
        MsgBox(sender.name, MsgBoxStyle.OkCancel, "测试")
End Sub

如下语句不成功

Private Sub 主界面_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    AddHandler 供货商IDSearchLookUpEdit.TextChanged, AddressOf 供货商IDSearchLookUpEdit_TextChanged
end sub

Private Sub 供货商IDSearchLookUpEdit_TextChanged(sender As Object, e As EventArgs)
        'Handles 供货商IDSearchLookUpEdit.TextChanged
        MsgBox(sender.name, MsgBoxStyle.OkCancel, "测试")
End Sub