当学生登录时，我为他们加载一个仪表板，让他们了解他们在住宿预订过程中的位置。无论我做什么，虽然它似乎总是触发Else条件，即使我在For..Next循环中有一个Exit For。以下是有问题的代码：
Public Sub Initialize_Dashboard()
Dim term As String = CStr(Session("term"))
Dim year As String = CStr(Session("year"))
Dim people_code_id As String = CStr(Session("people_code_id"))
Dim class_level As String = CStr(Session("class"))
' %%%%%% Show the resident's name and whether they have a room. %%%%%%
Dim dbroom As New pbu_housingEntities
Dim queryStudent = From p In dbroom.Residents _
Where p.people_code_id = people_code_id _
Join b In dbroom.Buildings On p.building Equals b.id _
Join r In dbroom.Rooms On p.room Equals r.id
Select p, b, r
lblName.Text = CStr(Session("name"))
If queryStudent.Count.Equals(0) Then
lblRegistered.Text = "We do not have you currently registered for campus housing."
Else
lblRegistered.Text = "You are currently registered for " & queryStudent.First.b.building_name & " " & queryStudent.First.r.room1 & "."
End If
' Initiate variables to check for class settings.
Dim dbConfig As New pbu_housingEntities
Dim whatdatest = From p In dbConfig.Configs
Dim whatdatee = From p In dbConfig.Configs
' Add in a check for contract signatures.
Dim dbContracts As New pbu_housingEntities
Dim clcexists = From p In dbContracts.Signatures _
Where p.StudentID = people_code_id _
And p.ContractType = "clc" _
Order By p.ID Descending _
Select p
Dim rhcexists = From p In dbContracts.Signatures _
Where p.StudentID = people_code_id _
And p.ContractType = "rhc" _
Order By p.ID Descending _
Select p
' Shows or hides the buttons for contracts based on whether signatures exist.
Dim clcfirst = clcexists.FirstOrDefault()
Dim rhcfirst = rhcexists.FirstOrDefault()
If clcfirst Is Nothing Then
pnlSignCLC.Visible = True
Else
pnlSignCLC.Visible = False
End If
If rhcfirst Is Nothing Then
pnlSignRHC.Visible = True
Else
pnlSignRHC.Visible = False
End If
' Determine if the student is eligible to register for class.
Dim classes() As String = {"FR%", "SO", "JR", "SR", "SR5"}
For Each value As String In classes
' Pull in the dates the student should be able to register for this class, compare them to the current date.
Dim current_value = value
If class_level = current_value Then
Response.Write("hello")
whatdatest = From p In dbConfig.Configs _
Where p.Description = current_value + "OD" _
Select p
whatdatee = From p In dbConfig.Configs _
Where p.Description = current_value + "CD" _
Select p
' If the current date is within their registration period...
If Date.Now >= whatdatest.First.dateValue And Date.Now <= whatdatee.First.dateValue Then
Dim person_name As String = CStr(Session("person_name")) ' Must stay here or will conflict.
Dim hasroom = From p In dbConfig.Residents _
Where p.person_name = person_name _
Where p.semester = term _
Where p.year = year _
Select p
' If they have signed their contracts, lets let them register for a room.
If hasroom.Count.Equals(0) AndAlso clcfirst IsNot Nothing AndAlso rhcfirst IsNot Nothing Then
pnlBegin.Visible = True
btnBegin.Enabled = True
' If they are already registered for a room, let them delete their reservation.
ElseIf clcfirst IsNot Nothing AndAlso rhcfirst IsNot Nothing Then
pnlDelete.Visible = True
btnDelete.Enabled = True
Else
' In any other situation, we don't need to do anything.
' There really shouldn't be any other situation.
End If
' What to do if the current date is not within the room reservation window.
Exit For
Else
Dim class_name As String
Select Case current_value
Case "FR%"
class_name = "Freshman"
Case "SO"
class_name = "Sophmore"
Case "JR"
class_name = "Junior"
Case "SR"
class_name = "Senior"
Case "SR5"
class_name = "Fifth year Senior"
End Select
lblError.Text = "You are currently a " & current_value & ". You will be eligible to reserve a room between" _
& whatdatest.First.dateValue & " and " & whatdatee.First.dateValue & ". Please come back during those dates. Thanks!"
End If
Exit For
Else
' What to do if the user isn't assigned a class level at all!
lblError.Text = "Oops...Something might be wrong with our records. We don't have you registered for classes. Please contact Dave Mackey, x4543."
End If
Next
这是我将最后一个else子句移动到单独的If..Then：
之后的代码 Public Sub Initialize_Dashboard()
Dim term As String = CStr(Session("term"))
Dim year As String = CStr(Session("year"))
Dim people_code_id As String = CStr(Session("people_code_id"))
Dim class_level As String = CStr(Session("class"))
' %%%%%% Show the resident's name and whether they have a room. %%%%%%
Dim dbroom As New pbu_housingEntities
Dim queryStudent = From p In dbroom.Residents _
Where p.people_code_id = people_code_id _
Join b In dbroom.Buildings On p.building Equals b.id _
Join r In dbroom.Rooms On p.room Equals r.id
Select p, b, r
lblName.Text = CStr(Session("name"))
If queryStudent.Count.Equals(0) Then
lblRegistered.Text = "We do not have you currently registered for campus housing."
Else
lblRegistered.Text = "You are currently registered for " & queryStudent.First.b.building_name & " " & queryStudent.First.r.room1 & "."
End If
' Initiate variables to check for class settings.
Dim dbConfig As New pbu_housingEntities
Dim whatdatest = From p In dbConfig.Configs
Dim whatdatee = From p In dbConfig.Configs
' Add in a check for contract signatures.
Dim dbContracts As New pbu_housingEntities
Dim clcexists = From p In dbContracts.Signatures _
Where p.StudentID = people_code_id _
And p.ContractType = "clc" _
Order By p.ID Descending _
Select p
Dim rhcexists = From p In dbContracts.Signatures _
Where p.StudentID = people_code_id _
And p.ContractType = "rhc" _
Order By p.ID Descending _
Select p
' Shows or hides the buttons for contracts based on whether signatures exist.
Dim clcfirst = clcexists.FirstOrDefault()
Dim rhcfirst = rhcexists.FirstOrDefault()
If clcfirst Is Nothing Then
pnlSignCLC.Visible = True
Else
pnlSignCLC.Visible = False
End If
If rhcfirst Is Nothing Then
pnlSignRHC.Visible = True
Else
pnlSignRHC.Visible = False
End If
' Determine if the student is eligible to register for class.
Dim classes() As String = {"FR%", "SO", "JR", "SR", "SR5"}
Dim flag As String = "N"
For Each value As String In classes
' Pull in the dates the student should be able to register for this class, compare them to the current date.
Dim current_value = value
If class_level = current_value Then
flag = "Y"
Response.Write("hello")
whatdatest = From p In dbConfig.Configs _
Where p.Description = current_value + "OD" _
Select p
whatdatee = From p In dbConfig.Configs _
Where p.Description = current_value + "CD" _
Select p
' If the current date is within their registration period...
If Date.Now >= whatdatest.First.dateValue And Date.Now <= whatdatee.First.dateValue Then
Dim person_name As String = CStr(Session("person_name")) ' Must stay here or will conflict.
Dim hasroom = From p In dbConfig.Residents _
Where p.person_name = person_name _
Where p.semester = term _
Where p.year = year _
Select p
' If they have signed their contracts, lets let them register for a room.
If hasroom.Count.Equals(0) AndAlso clcfirst IsNot Nothing AndAlso rhcfirst IsNot Nothing Then
pnlBegin.Visible = True
btnBegin.Enabled = True
' If they are already registered for a room, let them delete their reservation.
ElseIf clcfirst IsNot Nothing AndAlso rhcfirst IsNot Nothing Then
pnlDelete.Visible = True
btnDelete.Enabled = True
Else
' In any other situation, we don't need to do anything.
' There really shouldn't be any other situation.
End If
' What to do if the current date is not within the room reservation window.
Exit For
Else
Dim class_name As String
Select Case current_value
Case "FR%"
class_name = "Freshman"
Case "SO"
class_name = "Sophmore"
Case "JR"
class_name = "Junior"
Case "SR"
class_name = "Senior"
Case "SR5"
class_name = "Fifth year Senior"
End Select
lblError.Text = "You are currently a " & current_value & ". You will be eligible to reserve a room between" _
& whatdatest.First.dateValue & " and " & whatdatee.First.dateValue & ". Please come back during those dates. Thanks!"
End If
Exit For
Else
End If
Next
If flag = "N" Then
' What to do if the user isn't assigned a class level at all!
lblError.Text = "Oops...Something might be wrong with our records. We don't have you registered for classes. Please contact Dave Mackey, x4543."
End If
答案 0 :(得分：2)
我认为您需要删除最后一条Else语句
Else
' What to do if the user isn't assigned a class level at all!
lblError.Text = "Oops...Something might be wrong with our records. We don't have you registered for classes. Please contact Dave Mackey, x4543."
否则你将无法完成所有选项。
你需要在循环之前将“found”标志设置为false，如果匹配则在循环内设置为true，然后在循环之后设置错误，如果找到的仍然是假的。
答案 1 :(得分：0)
我可能会误解，但不是class_level <> current_value最可能的解释，这意味着执行直接进入Else块？绕过Exit For语句。
编辑关注您的评论。您循环遍历数组classes()中检查匹配项的所有可能值。如果current_value与第一个值“FR％”匹配，那么您肯定会到达Exit For。否则，您将转到Else行“如果用户根本没有分配班级，该怎么办”
我想也许你没有考虑过你的逻辑？