Question

我已经在asp.net页面上动态创建了一个表，方法是根据SQL数据库中数据集中的行数创建行。我使用for循环在page_load（）函数中使用填充的下拉列表创建我的行和单元格。我的表是根据需要创建的，但是我需要获取每行中每个单元格的选定项目文本，以便在单击提交按钮时存储回数据库表。我最初在我的asp页面上有一个占位符，并在加载时将其替换为创建的表。出于某种原因，当我尝试使用

时

对于每个r作为TableRow在LineupTable.Rows

 msgbox(EmployeeDDL.SelectedItem.Text)

下一个

它为employeeddl.selecteditem.text提供了一个空值错误。

这是我生成表格的方式。

'动态创建表行和单元格，并使用适当的控件和/或信息填充它们

        Dim numrows As Integer = dtEQP.Rows.Count
        Dim numcells As Integer = 6
        Dim j As Integer


        For j = 0 To numrows - 1
            r = New TableRow()
            c1 = New TableCell() With {.Width = 300}
            c1.Controls.Add(New LiteralControl(dtEQP.Rows(j).ItemArray(0)))
            r.Cells.Add(c1)

            c2 = New TableCell() With {.Width = 200}
        Dim EmployeeDDL As New DropDownList()
        EmployeeDDL.DataSource = dsEMP
        EmployeeDDL.DataTextField = "FirstName"
        EmployeeDDL.DataValueField = "ID"
        EmployeeDDL.DataBind()
        EmployeeDDL.Items.Insert(0, New ListItem("", "-1"))
        c2.Controls.Add(EmployeeDDL)
            r.Cells.Add(c2)

            c3 = New TableCell() With {.Width = 180}
            Dim CodeDDL As New DropDownList()
            CodeDDL.Items.Add("0-Running")
            CodeDDL.Items.Add("99-Idle")
            CodeDDL.Items.Add("60-Down")
            CodeDDL.Items.Add("1-Weather")
            CodeDDL.SelectedValue = "99-Idle"
            c3.Controls.Add(CodeDDL)
            r.Cells.Add(c3)

            c4 = New TableCell() With {.Width = 100}
            Dim RideDDL1 As New DropDownList()
            RideDDL1.DataSource = dsRide
            RideDDL1.DataTextField = "Ridename"
            RideDDL1.DataValueField = "RideID"
            RideDDL1.DataBind()
            RideDDL1.Items.Insert(0, New ListItem("", "-1"))
            c4.Controls.Add(RideDDL1)
            r.Cells.Add(c4)

            c5 = New TableCell() With {.Width = 200}
            Dim OTddl1 As New DropDownList()
            OTddl1.DataSource = dsEMP2
            OTddl1.DataTextField = "FirstName"
            OTddl1.DataValueField = "ID"
            OTddl1.DataBind()
            OTddl1.Items.Insert(0, New ListItem("", "-1"))
            c5.Controls.Add(OTddl1)
            r.Cells.Add(c5)


            c6 = New TableCell() With {.Width = 350}
            Dim CommentsTxtBx As New TextBox()
            c6.Controls.Add(CommentsTxtBx)
            r.Cells.Add(c6)


            LineupTable.Rows.Add(r)
        Next j

关于如何在点击子程序中检索此值以获取实际选择内容的任何想法？

Answer 1

首先添加DropDownList，给它一个ID（使用你的游标变量来避免重复的ID）：

EmployeeDDL.ID = "EmployeeDDL" & j.ToString()

其次，由于DropDownList是动态添加的，因此您需要使用FindControl来获取它的实例。另外，确保SelectedItem不为null / nothing。

Dim intCursor As Integer = 0
For Each r As TableRow In LineupTable.Rows

    Dim ddlTarget As DropDownList = Cast(r.Cells(1).FindControl("EmployeeDDL" & intCursor.ToString()), DropDownList)

    If Not ddlTarget.SelectedItem Is Nothing Then

        Dim strValue = ddlTarget.SelectedItem.Text

    End If

    intCursor += 1

Next r

从

1 个答案: