“GlobalConst”的类型初始值设定项引发异常

2008-04-03 05:00:43 232 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

JavaScript变量作用域：从TDZ、词法环境到闭包内存管理变量作用域是JavaScript执行时变量可见性与生命周期的底层机制，其核心在于词法环境、变量环境及外部引用构成的作用域链。它决定了var/let/const的行为差异（如提升与暂时性死区TDZ）、闭包的数据持久化能力，以及模块化中import/export的绑定关系。掌握作用域不仅规避ReferenceError和静默bug，更直接影响内存占用、tree-shaking有效性与React Hooks调用一致性。在真实场景中，它支撑着异步循环变量捕获、Service Worker缓存范围控制、严格模式安全加阅读详情

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
''''如果是为响应客户端回发而加载该页，则为 true；否则为 false。
If Not Page.IsPostBack Then
If Not Session("UserInfo") Is Nothing Then
Me.Response.Redirect("Default.aspx", True)
Else
If Not isEnter(Me) Is Nothing Then
Me.Response.Redirect("Default.aspx", True)
End If
End If
End If
End Sub
当执行到这里的时候If Not isEnter(Me) Is Nothing Then 会报出错误“GlobalConst”的类型初始值设定项引发异常，其中isenter是GlobalConst（Module）的一个函数。

Function isEnter(ByVal pPage As System.Web.UI.Page, Optional ByVal Userid As String = "")
Dim oUserInfo As New UserInfo
Dim strip As String = pPage.Request.ServerVariables("REMOTE_ADDR")
Dim strjqm As String = ""
'Try
' strjqm = Net.Dns.GetHostEntry(strip).HostName
'Catch ex As Exception
' strjqm = strip
'End Try
'Try
' If strip = "127.0.0.1" Then
' strip = Net.Dns.GetHostAddresses(strjqm)(0).ToString
' End If
'Catch ex As Exception
' strip = strjqm
'End Try

Dim isDBm As New DBManager.PropOracleDbManager
isDBm.DatabaseType = DBManager.enumDatabaseType.propDatabaseOracle
isDBm.ConnectionArgs = getStrCnn()
Try
If isDBm.GetConn.State = ConnectionState.Closed Then
isDBm.GetConn()
End If
Dim isSql As String = ""
If Userid <> "" Then
isSql = "select A.YHZH,A.YHMC,A.SSDWBS,A.ISADMIN,A.DZYJ,A.LXDH,to_char(entertime,'YYYY-MM-DD HH24:MM:SS') AS entertime from a4_sys_userinfo a, a4_sys_enter b " _
& " Where a.YHZH=b.enteruserid and to_char(Sysdate,'yymmddhh24mi')-to_char(entertime,'yymmddhh24mi')<120 and isstate=1" _
& " and enterjqm='" & strip & "'and enteruserid='" & Userid & "'"
Else
isSql = "select A.YHZH,A.YHMC,A.SSDWBS,A.ISADMIN,A.DZYJ,A.LXDH ,to_char(entertime,'YYYY-MM-DD HH24:MM:SS') AS entertime from a4_sys_userinfo a, a4_sys_enter b " _
& " Where a.YHZH=b.enteruserid and to_char(Sysdate,'yymmddhh24mi')-to_char(entertime,'yymmddhh24mi')<120 and isstate=1 " _
& " and enterjqm='" & strip & "' and enterip='" & strip & "'"
End If
Dim oRd As Data.OracleClient.OracleDataReader
oRd = isDBm.ExecuteReader(isSql)
If oRd Is Nothing Then
Return Nothing
End If
If oRd.HasRows Then
While oRd.Read
If Not oRd.IsDBNull(0) Then
oUserInfo.userID = oRd.Item(0).ToString
Else
oUserInfo.userID = ""
End If
If Not oRd.IsDBNull(1) Then
oUserInfo.userName = oRd.Item(1).ToString
Else
oUserInfo.userName = ""
End If
If Not oRd.IsDBNull(2) Then
oUserInfo.userOrg = oRd.Item(2).ToString
Else
oUserInfo.userOrg = ""
End If

If Not oRd.IsDBNull(3) Then
oUserInfo.isAdmin = oRd.Item(3).ToString
Else
oUserInfo.isAdmin = 0
End If
If Not oRd.IsDBNull(4) Then
oUserInfo.userEmail = oRd.Item(4).ToString
Else
oUserInfo.userEmail = ""
End If
If Not oRd.IsDBNull(5) Then
oUserInfo.userTel = oRd.Item(5).ToString
Else
oUserInfo.userTel = ""
End If
If Not oRd.IsDBNull(6) Then
oUserInfo.EnterTime = oRd.Item(6).ToString
Else
oUserInfo.EnterTime = Now
End If

End While
pPage.Session("UserInfo") = oUserInfo
Return oUserInfo
Else
oUserInfo = Nothing
Return Nothing
End If
Catch ex As Exception
Return Nothing
Finally
isDBm.CloseConn()
isDBm = Nothing
End Try

End Function

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