Question

我根据ID表中的行数来动态地将asp复选框添加到我的页面。此外，复选框还从db表中分配了一个ID。我的db表中还有两列＆＃34; numberOffered＆＃34;和＆＃34; numberAllowed＆＃34;。我的想法是页面加载只允许用户检查显示的10个复选框中的3个。我删除了很多我认为不必要的代码。非常感谢你提前。

For Each Arow As Object In ATable.Rows
    For Each Brow As Object In BTable.Rows
        If Brow(1) = a_ID Then
            If Brow(2) = b_ID Then
                Dim cbShown As Integer = Arow(5)
                Dim cbAllowed As Integer = Arow(6)
                Dim checkBox As New CheckBox()
            End If
        End If
    Next
Next

checkBox.ID = Crow(0)
divcontrol.Controls.Add(checkBox)

编辑：完整的Page_load sub

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not (Session("studentLoggedIn") Or Session("adminLoggedIn")) Then
            Routines.LogOut()
        End If

        If Session("adminLoggedIn") = True Then
            castVote.Enabled = False
            castVote.CssClass = "btnDisabled"
            Dim p As New HtmlGenericControl()
            p.TagName = "p"
            p.InnerText = "Vote button disabled. Only students may vote."
            adminMsg.Controls.Add(p)
        End If

        Dim ballot_ID As Integer = CType(Session.Item("ballot_ID"), Integer)
        Dim ballotName As String = CType(Session.Item("ballotName"), String)

        Dim ballotsAdapter As New eVoteTableAdapters.ballotsTableAdapter()
        Dim ballotsTable As New eVote.ballotsDataTable
        ballotsTable = ballotsAdapter.GetDataBy3getBallotsByID(ballot_ID)

        Dim sectionsAdapter As New eVoteTableAdapters.sectionsTableAdapter()
        Dim sectionsTable As New eVote.sectionsDataTable
        sectionsTable = sectionsAdapter.GetDataBygetsectionsByBallotID(ballot_ID)

        Dim candidatesAdapter As New eVoteTableAdapters.candidatesTableAdapter()
        Dim candidatesTable As New eVote.candidatesDataTable
        candidatesTable = candidatesAdapter.GetDataBygetCandidatesByballotID(ballot_ID)

        openBallotName.InnerText = ballotName

        Dim section_ID
        For Each row As Object In sectionsTable.Rows
            If row(1) = ballot_ID Then
                section_ID = row(0)
                Dim sectionName As New HtmlGenericControl()
                Dim sectionDescription As New HtmlGenericControl()
                Dim divcontrol As New HtmlGenericControl()
                Dim br As New HtmlGenericControl()
                divcontrol.Attributes("ID") = section_ID
                divcontrol.Attributes("runat") = "server"
                divcontrol.Attributes("style") = "border: solid;"
                divcontrol.TagName = "div"
                br.TagName = "br"
                sectionName.TagName = "h4"
                sectionDescription.TagName = "p"
                mainBallotDiv.Controls.Add(divcontrol)
                mainBallotDiv.Controls.Add(br)
                sectionName.InnerText = row(2)
                sectionDescription.InnerText = row(3)
                divcontrol.Controls.Add(sectionName)
                divcontrol.Controls.Add(sectionDescription)


                For Each Crow As Object In candidatesTable.Rows
                    If Crow(1) = ballot_ID Then
                        If Crow(2) = section_ID Then
                            Dim checkBox As New CheckBox()
                            Dim canImg As New Image()
                            Dim canName As New HtmlGenericControl()
                            Dim canBio As New HtmlGenericControl()
                            Dim rmImg As New Image()
                            Dim rmName As New HtmlGenericControl()
                            Dim rmBio As New HtmlGenericControl()
                            Dim canBytes As Byte() = Crow(6)
                            Dim canBase64String As String = Convert.ToBase64String(canBytes, 0, canBytes.Length)
                            Dim rmBytes As Byte() = Crow(11)
                            Dim rmBase64String As String = Convert.ToBase64String(rmBytes, 0, rmBytes.Length)
                            checkBox.ID = Crow(0)
                            canName.TagName = "h3"
                            canBio.TagName = "p"
                            rmName.TagName = "h3"
                            rmBio.TagName = "p"
                            canName.InnerText = Crow(4) & " " & Crow(5)
                            canBio.InnerText = Crow(7)
                            canImg.ImageUrl = Convert.ToString("data:image/png;base64,") & canBase64String
                            canImg.Height = 120
                            rmName.InnerText = Crow(9) & " " & Crow(10)
                            rmBio.InnerText = Crow(12)
                            rmImg.ImageUrl = Convert.ToString("data:image/png;base64,") & rmBase64String
                            rmImg.Height = 120
                            divcontrol.Controls.Add(checkBox)
                            divcontrol.Controls.Add(canImg)
                            divcontrol.Controls.Add(canName)
                            divcontrol.Controls.Add(canBio)
                            If row(4) = True Then
                                divcontrol.Controls.Add(rmImg)
                                divcontrol.Controls.Add(rmName)
                                divcontrol.Controls.Add(rmBio)
                            End If
                        End If
                    End If
                Next
            End If
        Next
    End Sub

Answer 1

您需要一个变量（整数）表示允许的复选框数量，然后是另一个变量表示当前选中的复选框数量，最后是一个包含每个复选框名称的List，（将所有这些变量作为类字段）

然后在你的事件处理程序中像

Sub Check_Clicked(sender As Object, e As EventArgs)

checked += 1        
        If checked >= NumberAllowedChecked Then
            For Each a As CheckBox In MyCheckBoxList
                   If Not CheckBox.Checked Then CheckBox.Enabled = False               
                Next
        End If
End Sub

我对VB并不过分熟悉，但我认为这应该让你在如何自己实现它的正确轨道上

编辑： 如果用户取消选中一个复选框，它将从“已选中”中删除一个，您将需要添加逻辑;

仅允许选中一些复选框。在page_load上加载

1 个答案: