Question

Below code i have to ammend for adding a dropdown in my asp website. I have already added could you please check what is wrong.

Function collectEmailBodyText()
        Try
            Dim counterEnd As Integer = subActivated_HowManyControlsInAPanel()
            Dim counter As Integer = 0
            Dim tempPanelLabel As Label
            Dim tempPanelInputBox As TextBox
            Dim tempPanelDropDownBox As DropDownList
            Dim tempCollector As String
            Dim panelUsed As String = ""
            '* Find out which panel is used to collect panel data:
            panelUsed = view0_panelUsed.ToString
            Response.Write("<!-- " + panelUsed + " -->")
            '
            tempCollector = "<p><b>" + lbl_viewTitle0.Text + "</b>"
            tempCollector = tempCollector + "<br>" + lbl_view0_firstName.Text + ": " + txt_firstName.Text
            tempCollector = tempCollector + "<br>" + lbl_view0_surname.Text + ": " + txtSurName.Text
            tempCollector = tempCollector + "<br>" + lbl_view0_ContactNum.Text + ": " + txt_contactNum.Text
            '
            tempCollector = tempCollector + "<p><b>" + lbl_viewTitle1.Text + "</b>"
            tempCollector = tempCollector + "<br>" + lbl_view1_firstName.Text + ": " + txt_view1_firstname.Text
            tempCollector = tempCollector + "<br>" + lbl_view1_surname.Text + ": " + txt_view1_surname.Text
            tempCollector = tempCollector + "<br>" + lbl_view1_userID.Text + " " + txt_view1_userID.Text
            tempCollector = tempCollector + "<br>" + lbl_view1_workUnit.Text + ": " + ddl_view1_workunit.SelectedItem.Text + " :: " + ddl_view1_workunit.SelectedValue.ToString()
            tempCollector = tempCollector + "<br>" + lbl_view0_typeOfRequest.Text + ": " + ddl_view0_typeOfRequest.SelectedItem.ToString
            tempCollector = tempCollector + "<br>" + lbl_view0_workUnitLevel.Text + ": " + ddl_view0_workUnitLevel.SelectedItem.ToString + "<br>"
            '
            '* Collect panel data:
            Do
                counter = counter + 1
                tempPanelLabel = New Label
                tempPanelInputBox = New TextBox
                tempPanelDropDownBox = New DropDownList
                tempPanelLabel = form1.FindControl("lbl_" + panelUsed + "_label" + counter.ToString())
                tempPanelInputBox = form1.FindControl("txt_" + panelUsed + "_input" + counter.ToString())
                tempPanelDropDownBox = DirectCast(form1.FindControl(("txt_" & panelUsed & "_ddinput") + counter.ToString()), DropDownList)

                tempCollector = tempCollector + "<br>" + tempPanelLabel.Text
                'tempCollector = tempCollector + ": " + tempPanelInputBox.Text
                tempCollector = tempCollector + ": " + tempPanelDropDownBox.SelectedValue


            Loop Until counter = counterEnd
            '
            If storeSelected() = 0 Then
                tempCollector = tempCollector + "<p><b>" + lbl_viewTitle2.Text + "</b>"
                tempCollector = tempCollector + "<br>" + lbl_view2_ManagersEmailAddress.Text + ": " + txt_view2_ManagersEmailAddress.Text
            End If
            '
            Return tempCollector
        Catch ex As Exception
            Return ex.ToString()
            Response.Write(ex.ToString())
        End Try

    End Function

Below is the extra line I added

tempPanelDropDownBox = DirectCast(form1.FindControl(("txt_" & panelUsed & "_ddinput") + counter.ToString()), DropDownList)

and I am getting the following error:

System.NullReferenceException: Object reference not set to an instance of an object. at WebApplication1._Default.collectEmailBodyText() in C:\v1.5_production_05June09\Default.aspx.vb:line 220

Answer 1

It would be easier to know which object is null given line numbers, but at a guess one of the lines in the form

tempPanelInputBox = form1.FindControl("txt_" + panelUsed + "_input" + counter.ToString())

is failing, this would be because the name generated by the part “txt_” + panelUsed + “_input” + counter.ToString() doesn’t match a control within the form.

So, look at the line 220 within the file, and check the control that it is looking for appears within the form.

After looking at it, I think the line

tempPanelDropDownBox = DirectCast(form1.FindControl(("txt_" & panelUsed & "_ddinput") + counter.ToString()), DropDownList)

should read

tempPanelDropDownBox = DirectCast(form1.FindControl(("txt_" & panelUsed & "_ddlinput") + counter.ToString()), DropDownList)

the difference being ddl in the name not dd (Based on assumption that you name drop downs ddl)