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Object reference not set to an instance of an object.

I have the following scenario. Users can select values from a drop down list and when the selected value changes it triggers the ddlMovement_SelectedIndexChanged. However I am getting the "Object reference not set to an instance of an object." error on line rEShipper.Visible = False. Can someone assist please?

Protected Sub ddlMovement_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim ddlMovement As DropDownList = fvShip.FindControl("ddlMovement")
        Dim rEShipper As TableRow = fvShip.FindControl("rEShipper")

              If ddlMovement.SelectedValue = "ADDITIONAL RECOVERY" Then
            rEShipper.Visible = False
                  Else
            rEShipper.Visible = True
                  End If
    End Sub

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Which gets triggered by the aspx page:

  <asp:FormView ID="fvShip" runat="server" DataSourceID="sdsShipDetail" CellPadding="0">
                        <EditItemTemplate>
                            <table border="0" id="EditTable">
  <tr>
                                    <td align="left">Type of Movement:</td>
                                    <td align="left"  colspan="4"><asp:DropDownList ID="ddlMovement" SelectedValue='<%# Bind("Movement_Name")%>'  runat="server" DataSourceID="sdsMovement" DataTextField="Movement_Name"
                            DataValueField="Movement_Name" CssClass="form" AutoPostBack="True" OnSelectedIndexChanged="ddlMovement_SelectedIndexChanged">
                        </asp:DropDownList>&nbsp;
                        <asp:SqlDataSource ID="sdsMovement" runat="server" ConnectionString="<%$ ConnectionStrings:BusDevConnectionString %>"
                            SelectCommand="View_Movement_DD_Dell" SelectCommandType="StoredProcedure"></asp:SqlDataSource>
                                    </td>
                                </tr>
<tr>
                                    <td>
                                        <asp:LinkButton ID="UpdateButton" runat="server" CausesValidation="True" ValidationGroup="PIRUpdate"  
                                            CommandName="Update" Text="Update" ></asp:LinkButton>
                                    </td>
                                    <td  colspan="4">
                                        <asp:LinkButton ID="UpdateCancelButton" runat="server" CausesValidation="False" CommandName="Cancel"
                                            Text="Cancel"></asp:LinkButton>
                                    </td>
                                </tr>
                            </table>
                            <div>
                            </div>
                        </EditItemTemplate>

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Andrew Crofts

It would seem that

Dim rEShipper As TableRow = fvShip.FindControl("rEShipper")

is not returning anything. (null)

I can't see a control called rEShipper in the mark up posted

JessyRobinson1234

ASKER

Sorry I should have put that in there as well. Here's the aspx code reposted

<asp:FormView ID="fvShip" runat="server" DataSourceID="sdsShipDetail" CellPadding="0">
                        <EditItemTemplate>
                            <table border="0" id="EditTable">
  <tr>
                                    <td align="left">Type of Movement:</td>
                                    <td align="left"  colspan="4"><asp:DropDownList ID="ddlMovement" SelectedValue='<%# Bind("Movement_Name")%>'  runat="server" DataSourceID="sdsMovement" DataTextField="Movement_Name"
                            DataValueField="Movement_Name" CssClass="form" AutoPostBack="True" OnSelectedIndexChanged="ddlMovement_SelectedIndexChanged">
                        </asp:DropDownList>&nbsp;
                        <asp:SqlDataSource ID="sdsMovement" runat="server" ConnectionString="<%$ ConnectionStrings:BusDevConnectionString %>"
                            SelectCommand="View_Movement_DD_Dell" SelectCommandType="StoredProcedure"></asp:SqlDataSource>
                                    </td>
                                </tr>
  <tr id="reShipper">
                                    <td align="left">Shipper Nbr / Return to Plant / Sort / IP:</td>
                                    <td align="left"  colspan="4"><asp:TextBox ID="txtShipper" runat="server" CssClass="form" Width="200px" Text='<%# Bind("Ship_Nbr") %>'></asp:textbox>
                                    </td>
                                </tr>
<tr>
                                    <td>
                                        <asp:LinkButton ID="UpdateButton" runat="server" CausesValidation="True" ValidationGroup="PIRUpdate"  
                                            CommandName="Update" Text="Update" ></asp:LinkButton>
                                    </td>
                                    <td  colspan="4">
                                        <asp:LinkButton ID="UpdateCancelButton" runat="server" CausesValidation="False" CommandName="Cancel"
                                            Text="Cancel"></asp:LinkButton>
                                    </td>
                                </tr>
                            </table>
                            <div>
                            </div>
                        </EditItemTemplate>

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Wiesje

I would assume it has to do with the fact that in the aspx code it is called reShipper as ID, but in your code you are looking for rEShipper.

JessyRobinson1234

ASKER

I changed it to be rEShipper but same error...

ASKER CERTIFIED SOLUTION

Alan Warren

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