FindControl Not Finding

[Rhys]

Hello All,

 I have a DropDown box inside a FormView, I have and even fireing on the selected index changed, but when I try and assigning the selected value or selected item of the DropDownList to a variable I get the great error “Object reference not set to an instance of an object.”

 

My Code is attached

 

Form

 

    <table style="width: 100%;">
        <tr>
            <td>
                <telerik:RadGrid ID="StockAdjustmentsRadGrid" runat="server"
                                 AllowPaging="True"
                                 AllowSorting="True"
                                 GridLines="None"
                                 DataSourceID="objDsGetAllAdjustments">
                    <MasterTableView AutoGenerateColumns="False" DataKeyNames="StockAdjustmentId" DataSourceID="objDsGetAllAdjustments">
                        <Columns>
                            <telerik:GridBoundColumn DataField="StockAdjustmentId" DataType="System.Int32" HeaderText="Stock Adjustment Id" ReadOnly="True" SortExpression="StockAdjustmentId" UniqueName="StockAdjustmentId" />
                            <telerik:GridBoundColumn DataField="ItemCode" HeaderText="Item Code" ReadOnly="True" SortExpression="ItemCode" UniqueName="ItemCode" />
                            <telerik:GridBoundColumn DataField="PrintRoomName" HeaderText="Print Room" ReadOnly="True" SortExpression="PrintRoomName" UniqueName="PrintRoomName" />
                            <telerik:GridBoundColumn DataField="Date" DataType="System.DateTime" HeaderText="Date" SortExpression="Date" UniqueName="Date" />
                            <telerik:GridBoundColumn DataField="AdjustmentAmount" DataType="System.Decimal" HeaderText="AdjustmentAmount" SortExpression="AdjustmentAmount" UniqueName="AdjustmentAmount" />
                            <telerik:GridBoundColumn DataField="AdjustmentReason" HeaderText="AdjustmentReason" SortExpression="AdjustmentReason" UniqueName="AdjustmentReason" />
                        </Columns>
                    </MasterTableView>
                    <ClientSettings>
                        <Selecting AllowRowSelect="True" />
                    </ClientSettings>
                </telerik:RadGrid>
            </td>
        </tr>
        <tr>
            <td>
                <asp:FormView ID="StockAdjustmentFormView" runat="server"
                              DataKeyNames="StockAdjustmentId"
                              DataSourceID="objDsStockAdjustment"
                              DefaultMode="Insert"
                              Width="960px">
                    <InsertItemTemplate>
                        <table style="width: 100%;">
                            <tr>
                                <td class="MasterFilesLableCells"><asp:Label ID="ItemCodeLabel" runat="server" meta:resourcekey="ItemCodeLabel" /></td>
                                <td class="MasterFilesDataCells">
                                    <telerik:RadComboBox ID="ItemCodeRadComboBox" Runat="server"
                                                         DataSourceID="objDsItemNames"
                                                         DataTextField="ItemCode"
                                                         DataValueField="ItemId"
                                                         AppendDataBoundItems="True"
                                                         OnSelectedIndexChanged="ItemCodeRadComboBox_SelectedIndexChanged"
                                                         AutoPostBack="True"
                                                         CausesValidation="False">
                                        <Items>
                                            <telerik:RadComboBoxItem runat="server" Selected="True" text="Select An Item" Value="-1" />
                                        </Items>
                                    </telerik:RadComboBox>
                                </td>
                            </tr>
                            <tr>
                                <td class="MasterFilesLableCells"><asp:Label ID="PrintroomNamesLabel" runat="server" meta:resourcekey="PrintroomNamesLabel" /></td>
                                <td class="MasterFilesDataCells"><uc2:PrintroomNames ID="PrintroomNames1" runat="server" SelectedValue='<%# Bind("PrintRoomName") %>'  /></td>
                            </tr>
                            <tr>
                                <td class="MasterFilesLableCells"><asp:Label ID="ItemCostLabel" runat="server" meta:resourcekey="ItemCostLabel" /></td>

                                <td class="MasterFilesDataCells">
                                    <asp:Label ID="LabelItemCost" runat="server" Text='<%# Bind("ItemCost") %>' />
                                </td>
                            </tr>
                             <tr>
                                <td colspan="2">
                                    <asp:RadioButton ID="RadioButtonAdjustUp" runat="server" Text="Adjust Up" GroupName="AdjustDirection" Checked='<%# Bind("AdjustDirectionUp") %>' />
                                    <asp:RadioButton ID="RadioButtonAdjustDown" runat="server" Text="Adjust Down" GroupName="AdjustDirection" Checked='<%# Bind("AdjustDirectionDown") %>' />
                                 </td>
                            </tr>
                            <tr>
                                 <td class="MasterFilesLableCells"><asp:Label ID="AdjustmentAmountLabel" runat="server" meta:resourcekey="AdjustmentAmountLabel" /></td>
                                <td><telerik:RadTextBox ID="AdjustmentAmountTextBox" runat="server" Text='<%# Bind("AdjustmentAmount") %>'  Skin="Windows7" /></td>
                            </tr>
                            <tr>
                                <td class="MasterFilesLableCells"><asp:Label ID="AdjustmentDateLabel" runat="server" meta:resourcekey="AdjustmentDateLabel" /></td>
                                <td class="MasterFilesDataCells">
                                    <telerik:RadDatePicker ID="AdjustmentDateLabelRadDatePicker" runat="server" SelectedDate='<%# Bind("AdjustmentDate") %>' >
                                    </telerik:RadDatePicker>
                                </td>
                            </tr>
                            <tr>
                                <td colspan="2"><asp:Label ID="AdjustmentReasonLabel" runat="server" meta:resourcekey="AdjustmentReasonLabel" /></td>
                            </tr>
                            <tr>
                                <td colspan="2">
                                    <telerik:RadTextBox ID="AdjustmentReasonTextBox" runat="server" Text='<%# Bind("AdjustmentReason") %>' Rows="5" Width="450" Height="50" TextMode="MultiLine" />
                                </td>
                            </tr>
                            <tr>
                                <td><asp:LinkButton ID="InsertButton" runat="server" CausesValidation="True" CommandName="Insert" Text="Insert" /></td>
                                <td align="right"><asp:LinkButton ID="InsertCancelButton" runat="server" CausesValidation="False" CommandName="Cancel" Text="Cancel" /></td>
                            </tr>
                        </table>
                    </InsertItemTemplate>
                    <ItemTemplate>
                        <table style="width: 100%;">
                            <tr>
                                <td class="MasterFilesLableCells"><asp:Label ID="ItemCodeLabel" runat="server" meta:resourcekey="ItemCodeLabel" /></td>
                                <td class="MasterFilesDataCells"><asp:Label ID="ItemNames1" runat="server" text='<%# Bind("ItemName") %>' /></td>
                            </tr>
                            <tr>
                                <td class="MasterFilesLableCells"><asp:Label ID="PrintroomNamesLabel" runat="server" meta:resourcekey="PrintroomNamesLabel" /></td>
                                <td class="MasterFilesDataCells"><asp:Label ID="PrintroomNames1" runat="server" text='<%# Bind("PrintName") %>' /></td>
                            </tr>
                            <tr>
                                <td class="MasterFilesLableCells"><asp:Label ID="ItemCostLabel" runat="server" meta:resourcekey="ItemCostLabel" /></td>
                                <td class="MasterFilesDataCells"><asp:Label ID="Label1" runat="server" Text='<%# Bind("ItemCost") %>' /></td>
                            </tr>
                             <tr>
                                <td colspan="2">
                                    <asp:RadioButton ID="RadioButtonAdjustUp" runat="server" Text="Adjust Up" Enabled="false" GroupName="AdjustDirection" Checked='<%# Bind("AdjustDirectionUp") %>' />
                                    <asp:RadioButton ID="RadioButtonAdjustDown" runat="server" Text="Adjust Down" Enabled="false" GroupName="AdjustDirection" Checked='<%# Bind("AdjustDirectionDown") %>' />
                                 </td>
                            </tr>
                            <tr>
                                 <td class="MasterFilesLableCells"><asp:Label ID="AdjustmentAmountLabel" runat="server" meta:resourcekey="AdjustmentAmountLabel" /></td>
                                <td><telerik:RadTextBox ID="AdjustmentAmountTextBox" Enabled="false" runat="server" Text='<%# Bind("AdjustmentAmount") %>'  Skin="Windows7" /></td>
                            </tr>
                            <tr>
                                <td class="MasterFilesLableCells"><asp:Label ID="AdjustmentDateLabel" runat="server" meta:resourcekey="AdjustmentDateLabel" /></td>
                                <td class="MasterFilesDataCells"><telerik:RadDatePicker Enabled="false" ID="AdjustmentDateLabelRadDatePicker" runat="server" Skin="Windows7" SelectedDate='<%# Bind("AdjustmentDate") %>' /></td>
                            </tr>
                            <tr>
                                <td colspan="2" class="MasterFilesLableCells"><asp:Label ID="AdjustmentReasonLabel" runat="server" meta:resourcekey="AdjustmentReasonLabel" /></td>
                            </tr>
                            <tr>
                                <td colspan="2" class="MasterFilesDataCells">
                                    <telerik:RadTextBox ID="AdjustmentReasonTextBox" runat="server" Text='<%# Bind("AdjustmentReason") %>'  Skin="Windows7" Rows="5" Width="450" Height="50" TextMode="MultiLine" />
                                </td>
                            </tr>
                            <tr>
                                <td><asp:LinkButton ID="InsertButton" runat="server" CausesValidation="True" CommandName="Insert" Text="Insert" /></td>
                                <td align="right"><asp:LinkButton ID="InsertCancelButton" runat="server" CausesValidation="False" CommandName="Cancel" Text="Cancel" /></td>
                            </tr>
                        </table>
                    </ItemTemplate>
                </asp:FormView>

            </td>
        </tr>
    </table>

Code Behind

 

Imports SBIS.FMSuite.Items.ItemMasterDAL
Partial Public Class StockAdjustment

    Inherits System.Web.UI.Page


    Protected Sub ItemCodeRadComboBox_SelectedIndexChanged(ByVal o As Object, ByVal e As Telerik.Web.UI.RadComboBoxSelectedIndexChangedEventArgs)
        Dim ItemId As String
        Dim ItemCodeRadComboBox As Telerik.Web.UI.RadComboBox = CType(FindControl("ItemCodeRadComboBox"), Telerik.Web.UI.RadComboBox)
        Dim LabelItemCost As Label = CType(FindControl("LabelItemCost"), Label)

        If ItemCodeRadComboBox.SelectedValue.ToString IsNot Nothing Then
            ItemId = ItemCodeRadComboBox.SelectedValue
        Else
            ItemId = 560
        End If

        Dim ItemsAPI As New SBIS.FMSuite.Items.ItemMasterBLL
        Dim Items As ItemsDataTable = ItemsAPI.GetItemsByItemID(ItemId)
        Dim Item As SBIS.FMSuite.Items.ItemMasterDAL.ItemsRow = Items(0)
        Try
            If Item.CostingMethod = "Last cost price" Then
                LabelItemCost.Text = Item.LastCostPrice
            Else
                LabelItemCost.Text = Item.AverageCostPrice
            End If
        Catch ex As Exception
            LabelItemCost.Text = ex.Message.ToString
        End Try

    End Sub

End Class

Thank you in advance

[Veronica]

Hello Rhys,

The problem is that you are trying to find the RadComboBox in the Page. You should fin the FormView first and then the RadComboBox inside:

Dim combo As RadComboBox = DirectCast(FormView1.FindControl("RadComboBox1"), RadComboBox)

Hope this helps.

All the best,
Veronica Milcheva
the Telerik team