1.Protected Sub Page_PreInit(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreInit
如果有MasterPage的话，在这里执行MasterPage里面的page事件，事件顺序在这篇文章里有写道

1.Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
2.Protected Sub Page_InitComplete(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.InitComplete
3.Protected Sub Page_PreLoad(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreLoad
4.Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
5.Protected Sub Page_LoadComplete(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.LoadComplete
6.Protected Sub Page_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRender
7.Protected Sub Page_PreRenderComplete(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRenderComplete
8.Protected Sub Page_SaveStateComplete(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.SaveStateComplete