0

Hi and thanks ahead of time:
I need an editable gridview with an Access database as it's source.
The findcontrol is not finding control in gridview (dropdownlist).
I have the following gridview:

<asp:GridView ID="gvRescue" 
                  runat="server" 
                  AutoGenerateColumns="False" 
                  onrowcancelingedit="gvRescue_RowCancelingEdit" 
                  onrowediting="gvRescue_RowEditing" 
                  onrowupdating="gvRescue_RowUpdating" 
                  onrowdatabound="gvRescue_RowDataBound">
                  <Columns>
                    <asp:TemplateField HeaderText="ID">
                        <ItemTemplate >
                            <asp:Label ID="lblID" runat="server" Text='<%# Eval("PersonPlaceID") %>' > </asp:Label>
                      </ItemTemplate>
                    </asp:TemplateField>
                    
                    <asp:TemplateField HeaderText="FirstName">
                    <ItemTemplate >
                        <asp:Label ID="lblFirstName" runat="server" Text='<%# Eval("FirstName") %>' > </asp:Label>
                    </ItemTemplate>
                    <EditItemTemplate >
                        <asp:TextBox ID="txtFirstName" runat="server" Width="50px" Text='<%# Eval("FirstName")%>'  ></asp:TextBox>
                    </EditItemTemplate>
                    </asp:TemplateField>
                    
                    <asp:TemplateField HeaderText="Last&lt;br&gt;Name" SortExpression="LastName">
                      <ItemTemplate> 
                          <asp:Label ID="lblLastName" runat="server" Text='<%# Eval("LastName") %>'></asp:Label> 
                      </ItemTemplate>
                      <EditItemTemplate>
                         <asp:TextBox ID="txtLastName" runat="server" Width="50px" Text='<%# Eval("LastName") %>'></asp:TextBox>
                      </EditItemTemplate>
                    </asp:TemplateField>
                    
                      <asp:TemplateField HeaderText="Role ID" >
                         <ItemTemplate>
                            <asp:Label ID="lblRoleID" runat="server" Text='<%# Eval("RoleID") %>'></asp:Label>
                         </ItemTemplate>
                         <EditItemTemplate>
                            <asp:TextBox ID="txtRoleID" runat="server" Width="50px" Text='<%# Eval("RoleID") %>'></asp:TextBox>
                         </EditItemTemplate>
                     </asp:TemplateField>
                            
                  <asp:TemplateField HeaderText="Role&lt;br&gt;(Rescue&lt;br&gt;Foster&lt;br&gt;Adopter">
                     <ItemTemplate >
                        <asp:Label ID="lblRescueRole" runat="server" Text='<%# Eval("RescueRole") %>'></asp:Label>
                     </ItemTemplate>
                    <EditItemTemplate >
                         <asp:DropDownList ID="ddRoles" runat="server" > </asp:DropDownList>
                    </EditItemTemplate>
                   </asp:TemplateField>
                              
                     <asp:TemplateField HeaderText="Address" >
                            <ItemTemplate>
                              <asp:Label ID="lblAddress" runat="server" Text='<%# Eval("Address") %>'></asp:Label>
                           </ItemTemplate>
                           <EditItemTemplate>
                              <asp:TextBox ID="txtAddress" runat="server" Width="150px" Text='<%# Eval("Address") %>'></asp:TextBox>
                           </EditItemTemplate>
                       </asp:TemplateField>
                            
                       <asp:TemplateField HeaderText="City" SortExpression="City">
                           <ItemTemplate>
                               <asp:Label ID="lblCity" runat="server" Text='<%# Eval("City") %>'></asp:Label>
                           </ItemTemplate>
                           <EditItemTemplate>
                                <asp:TextBox ID="txtCity" runat="server" Width="150px" Text='<%# Eval("City") %>'></asp:TextBox>
                           </EditItemTemplate>
                        </asp:TemplateField>
                        
                        <asp:TemplateField HeaderText="State ID" >
                           <EditItemTemplate>
                               <asp:TextBox ID="txtStateID" runat="server" Width="20px" Text='<%# Eval("StateID") %>'></asp:TextBox>
                           </EditItemTemplate>
                           <ItemTemplate>
                              <asp:Label ID="lblStateID" runat="server" Text='<%# Eval("StateID") %>'></asp:Label>
                           </ItemTemplate>
                         </asp:TemplateField>
                            
                       <asp:TemplateField HeaderText="State">
                            <ItemTemplate >
                                <asp:Label ID="lblState" runat="server" Text='<%# Eval("RescueState") %>'></asp:Label>
                            </ItemTemplate>
                            <EditItemTemplate >
                                 <asp:DropDownList ID="ddStates" runat="server" DataTextField="State" DataValueField="StateID"> </asp:DropDownList>
                          </EditItemTemplate>
                        </asp:TemplateField>
                                                              
                         <asp:TemplateField HeaderText="Zip" SortExpression="Zip">
                             <ItemTemplate>
                                <asp:Label ID="lblZip" runat="server" Text='<%# Eval("Zip") %>'></asp:Label>
                             </ItemTemplate>
                             <EditItemTemplate>
                                 <asp:TextBox ID="txtZip" runat="server" Width="50px" Text='<%# Eval("Zip") %>'></asp:TextBox>
                             </EditItemTemplate>
                         </asp:TemplateField>
                            
                            <asp:TemplateField HeaderText="1st Phone" >
                                <ItemTemplate>
                                    <asp:Label ID="lblPhone1" runat="server" Text='<%# Eval("Phone1") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:TextBox ID="txtPhone1" runat="server" Width="60px" Text='<%# Eval("Phone1") %>'></asp:TextBox>
                                </EditItemTemplate>
                            </asp:TemplateField>
                            
                            <asp:TemplateField HeaderText="2nd Phone" >
                                 <ItemTemplate>
                                    <asp:Label ID="lblPhone2" runat="server" Text='<%# Eval("Phone2") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:TextBox ID="txtPhone2" runat="server" Width="60px" Text='<%# Eval("Phone2") %>'></asp:TextBox>
                                </EditItemTemplate>
                            </asp:TemplateField>
                            
                            <asp:TemplateField HeaderText="3rd Phone" >
                                <ItemTemplate>
                                    <asp:Label ID="lblPhone3" runat="server" Text='<%# Eval("Phone3") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:TextBox ID="Phone3" runat="server" Width="60px" Text='<%# Eval("Phone3") %>'></asp:TextBox>
                                </EditItemTemplate>
                            </asp:TemplateField>
                            
                            <asp:TemplateField HeaderText="Email" >
                                <ItemTemplate>
                                    <asp:Label ID="lblEmail" runat="server" Text='<%# Eval("Email") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:TextBox ID="txtEmail" runat="server" Width="150px" Text='<%# Eval("Email") %>'></asp:TextBox>
                                </EditItemTemplate>
                            </asp:TemplateField>
                            
                            <asp:TemplateField HeaderText="Website" >
                                <ItemTemplate>
                                    <asp:Label ID="lblWebsite" runat="server" Text='<%# Eval("Website") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:TextBox ID="txtWebsite" runat="server" Width="150px" Text='<%# Eval("Website") %>'></asp:TextBox>
                                </EditItemTemplate>
                            </asp:TemplateField>
                            
                            <asp:TemplateField HeaderText="UserName" >
                                <ItemTemplate>
                                    <asp:Label ID="lblUserName" runat="server" Text='<%# Eval("UserName") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:TextBox ID="txtUserName" runat="server" Width="50px" Text='<%# Eval("UserName") %>'></asp:TextBox>
                                </EditItemTemplate>
                             </asp:TemplateField>
                            
                            <asp:TemplateField HeaderText="PassWord" >
                                 <ItemTemplate>
                                    <asp:Label ID="lblPassWord" runat="server" Text='<%# Eval("UserPassWord") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:TextBox ID="txtPassWord" runat="server" Width="50px" Text='<%# Eval("UserPassWord") %>'></asp:TextBox>
                                </EditItemTemplate>
                            </asp:TemplateField>
                            
                            <asp:TemplateField HeaderText="Rescue&lt;br&gt;Contact" >
                               <ItemTemplate>
                                    <asp:Label ID="lblContact" runat="server" Text='<%# Eval("RescueContactName") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:TextBox ID="txtContact" runat="server" Width="75px" Text='<%# Eval("RescueContactName") %>'></asp:TextBox>
                                </EditItemTemplate>
                             </asp:TemplateField>
                            
                            <asp:TemplateField HeaderText="Rescue&lt;br&gt;Criteria" >
                                <ItemTemplate>
                                    <asp:Label ID="lblCriteria" runat="server" Text='<%# Eval("RescueCriteria") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:TextBox ID="txtCriteria" runat="server" Width="200px" Text='<%# Eval("RescueCriteria") %>'></asp:TextBox>
                                </EditItemTemplate>
                             </asp:TemplateField>
                            
                            <asp:TemplateField HeaderText="Comment" >
                                <ItemTemplate>
                                    <asp:Label ID="lblComment" runat="server" Text='<%# Eval("PersonPlaceComment") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:TextBox ID="txtComment" runat="server" TextMode="MultiLine" Width="200px" Text='<%# Eval("PersonPlaceComment") %>'></asp:TextBox>
                                </EditItemTemplate>
                            </asp:TemplateField>
                            
                            <asp:TemplateField HeaderText="Approved&lt;br&gt;For&lt;br&gt;Website">
                                <ItemTemplate >
                                    <asp:Label ID="lblApproved" runat="server" Text='<%# Eval("Approved") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate >
                                    <asp:CheckBoxList ID="CheckBoxApproved" runat="server" >  
                                            <asp:ListItem>Approved</asp:ListItem>
                                    </asp:CheckBoxList>
                                </EditItemTemplate>
                            </asp:TemplateField>
                    
                            <asp:TemplateField HeaderText="Edit" ShowHeader="false">
                                <ItemTemplate>
                                       <asp:Button ID="btnedit" runat="server" CommandName="Edit" Text="Edit" ></asp:Button>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:Button ID="btnupdate" runat="server" CommandName="Update" Text="Update" ></asp:Button>
                                    <asp:Button ID="btncancel" runat="server" CommandName="Cancel" Text="Cancel"></asp:Button>
                                 </EditItemTemplate>
                             </asp:TemplateField>
                        </Columns>
                     </asp:GridView>

Here is where I'm trying to load the dropdownlist in the gridview:

Protected Sub gvRescue_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles gvRescue.RowDataBound

        Dim drv As DataRowView = e.Row.DataItem
        'if its a row in the datagrid
        If e.Row.RowType = DataControlRowType.DataRow Then
            If (e.Row.RowState & DataControlRowState.Edit) > 0 Then

                Dim dp As DropDownList = CType(e.Row.Cells(4).FindControl("ddRoles"), DropDownList)
             
                Dim dt As DataTable = LoadRoles()
                Dim i As Integer = 0
                For z As Integer = 0 To dt.Rows.Count - 1
                    Dim lt As New ListItem
                    lt.Text = dt.Rows(i)(0).ToString
                    dp.Items.Add(lt)
                Next
                dp.SelectedValue = drv(3).ToString
            End If
        End If
End Sub

The code is bombing out on the following line:

dp.Items.Add(lt)

Error is: object not set to an instance of an object
When I step through the code the following line has value of "nothing":

Dim dp As DropDownList = CType(e.Row.Cells(4).FindControl("ddRoles"), DropDownList

So I think error is because dp (dropdownlist) isn't found in the gridview.
This is the code where the dropdownlist is getting it's source:

Public Function LoadRoles()
        Dim dt As New DataTable
        Dim DBConnection As OleDbConnection = Dogs.MyConnection
        Dim DBAdapter As New OleDbDataAdapter
        Try
            DBConnection.Open()

            Dim sSelect As String = "SELECT Role, RoleID from Roles ORDER BY Role;"
            Dim cmd As New OleDbCommand(sSelect)
            cmd.CommandType = CommandType.Text
            cmd.Connection = DBConnection
            DBAdapter.SelectCommand = cmd
            DBAdapter.Fill(dt)
        Catch ex As Exception
            lblMessage.Visible = True
            lblMessage.Text = ex.Message

            ' lblMessage.Text = "<font color=red>Problem accessing Role records." _
            '  & " Please contact Programmer or CaliDogs.org.</font>"
            Me.SetFocus(lblMessage)
        Finally
            DBConnection.Close()
            DBConnection.Dispose()

        End Try

This is the code for datasource of gridview - called in page_load event:

Protected Sub ShowGrid(ByVal vRescueID As Integer)
        Dim dtRescue As New DataTable
        Dim DBConnection As OleDbConnection = Dogs.MyConnection
        Dim DBAdapter As New OleDbDataAdapter
        Try
            DBConnection.Open()

            Dim sSelect As String = "SELECT PersonPlace.PersonPlaceID, State.StateID, PersonPlace_Roles.FKRoleID AS RoleID, PersonPlace.FirstName, PersonPlace.LastName, Roles.Role AS RescueRole, PersonPlace.Address, PersonPlace.City, State.StateAbbv AS RescueState, PersonPlace.Zip, PersonPlace.Phone1, PersonPlace.Phone2, PersonPlace.Phone3, PersonPlace.Email, PersonPlace.Website, PersonPlace.UserName, PersonPlace.UserPassWord, PersonPlace.RescueContactName, PersonPlace.RescueCriteria, PersonPlace.PersonPlaceComment, PersonPlace.Approved, PersonPlace_Roles.FKRoleID FROM ((PersonPlace INNER JOIN PersonPlace_Roles ON PersonPlace.PersonPlaceID=PersonPlace_Roles.FKPersonPlaceID) INNER JOIN State ON PersonPlace.StateID=State.StateID) LEFT JOIN Roles ON PersonPlace_Roles.FKRoleID=Roles.RoleID WHERE (PersonPlace_Roles.FKRoleID=3 Or PersonPlace_Roles.FKRoleID=4 Or PersonPlace_Roles.FKRoleID=5) And (PersonPlace.PersonPlaceID = 11) ORDER BY PersonPlace.LastName;"
            Dim cmd As New OleDbCommand(sSelect)
            cmd.CommandType = CommandType.Text
            cmd.Connection = DBConnection
            DBAdapter.SelectCommand = cmd
            DBAdapter.Fill(dtRescue)

            gvRescue.DataSource = dtRescue
            gvRescue.DataBind()
        Catch ex As Exception
            lblMessage.Visible = True
            lblMessage.Text = ex.Message

            ' lblMessage.Text = "<font color=red>Problem accessing Rescue/Foster/Adopter records." _
            '   & " Please contact Programmer or CaliDogs.org.</font>"
            Me.SetFocus(lblMessage)
        Finally
            DBConnection.Close()
            DBConnection.Dispose()
        End Try
    End Sub
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Last Post by chenschel
0

It has been a bit since I've done something similar to this, but the thought that comes to mind is that ddRoles is inside an edit item template.

I believe that this is only rendered when the item is being selected for edit. So any reference to that object would result in a null, as the template has not been rendered.

Anyway, just a thought. Might want to look into it, but I may be way off my rocker as well.

0

Do a check along the lines of

if e.row.rowindex = gridview.editindex
    e.row.findcontrol(control name)
end if

That syntax isn't correct, but the logic should be

as was said above, if the current row isn't in edit mode then the drop down won't exist for that row and you'll get that error

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