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Can't Find Value inside Gridview Extended.

Hi

I've just added a new textbox to an extended gridview control but I cannot find the control in the code behind. This is code I've inherited from someone else but now I need to update it. If I hardcode the values into the codebehind for 'PercentageComplete 'the insert and update queries work so I know it must be something to do with this

 Dim PercentageComplete As TextBox = TryCast(gvUnits.Rows(i).Cells(1).Controls(3), TextBox)

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Full Gridview Extended

          <asp:Panel ID="panelEventUnits" runat="server" Visible="false">
                            <aspcc:GridViewExtended ID="gvUnits" runat="server" AutoGenerateColumns="False" CssClass="table table-condensed table-responsive" ShowFooterWhenEmpty="True"
                                DataSourceID="DSUnits" ShowFooter="True" ShowHeaderWhenEmpty="True" DataKeyNames="EVENTUNITID,PercentageComplete" GridLines="None" OnPreRender="gv_PreRender">
                                <Columns>
                                    <asp:BoundField DataField="QUALSCHEMEUNITID" HeaderText="QUALSCHEMEUNITID" SortExpression="QUALSCHEMEUNITID" Visible="False"></asp:BoundField>
                                    <asp:TemplateField HeaderText="QUALSCHEMEUNITID" SortExpression="QUALSCHEMEUNITID">
                                        <EditItemTemplate>
                                            <aspcc:DropDownListWithTitle ID="DropDownList57" runat="server" DataSourceID="DSUnitAvailable" CssClass="selectpickedr" data-live-search="true"
                                                DataTextField="UNIT" DataValueField="QUALSCHEMEUNITID" CustomProperty="QUALSCHEMEUNIT" SelectedValue='<%# Bind("QUALSCHEMEUNITID") %>'>
                                            </aspcc:DropDownListWithTitle>
                                        </EditItemTemplate>
                                        <ItemTemplate>
                                            <aspcc:DropDownListWithTitle ID="DropDownList571" runat="server" DataSourceID="DSUnitAvailable" CssClass="selectpickedr" data-live-search="true"
                                                DataTextField="UNIT" DataValueField="QUALSCHEMEUNITID" CustomProperty="QUALSCHEMEUNIT" SelectedValue='<%# Bind("QUALSCHEMEUNITID") %>'>
                                            </aspcc:DropDownListWithTitle>
                                        </ItemTemplate>
                                        <FooterTemplate>
                                            <aspcc:DropDownListWithTitle ID="DropDownList572" runat="server" AppendDataBoundItems="true" CssClass="selectpickedr"
                                                DataSourceID="DSUnitAvailable" DataTextField="UNIT" DataValueField="QUALSCHEMEUNITID" CustomProperty="QUALSCHEMEUNIT" data-live-search="true">
                                                <asp:ListItem Value="0" title="-Select-">-Select-</asp:ListItem>
                                            </aspcc:DropDownListWithTitle>
                                        </FooterTemplate>
                                    </asp:TemplateField>
                                    <asp:BoundField DataField="TYPE" HeaderText="TYPE" SortExpression="TYPE" />
                                    <asp:TemplateField HeaderText="% Complete">
                                        <EditItemTemplate>
                                            <asp:TextBox ID="txtPerComplete" runat="server" Text='<%# Bind("PercentageComplete") %>' Width="75px"></asp:TextBox>
                                        </EditItemTemplate>
                                        <FooterTemplate>
                                            <asp:TextBox ID="txtPerComplete" runat="server" Text='<%# Bind("PercentageComplete") %>' Width="75px"></asp:TextBox>
                                        </FooterTemplate>
                                        <ItemTemplate>
                                            <asp:TextBox ID="txtPerComplete" runat="server" Text='<%# Bind("PercentageComplete") %>' Width="75px"></asp:TextBox>
                                        </ItemTemplate>
                                    </asp:TemplateField>
                                </Columns>
                            </aspcc:GridViewExtended>
                            <div class="pull-right PadBtm">
                                <asp:Button ID="cmdUpateUnits" runat="server" Text="Update Units"
                                    OnClick="cmdUpateUnits_Click" CssClass="btn btn-success" />
                                <asp:Button ID="cmdResetUnits" runat="server" CssClass="btn btn-default" OnClick="cmdResetUnits_Click" Text="Cancel" />
                            </div>
                        </asp:Panel>

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Code Behind

 Protected Sub cmdUpateUnits_Click(sender As Object, e As EventArgs) Handles cmdUpateUnits.Click
        'Create sql connection and command
        Dim con As New SqlConnection(ConnectionString)
        Dim cmd As New SqlCommand()

        For i As Integer = 0 To gvUnits.Rows.Count - 1
            Try
                Dim ID As [Object] = gvUnits.DataKeys(i).Value
                Dim QUALSCHEMEUNITID As DropDownList = TryCast(gvUnits.Rows(i).Cells(1).Controls(1), DropDownList)
                Dim PercentageComplete As TextBox = TryCast(gvUnits.Rows(i).Cells(1).Controls(3), TextBox)

                Dim strUpdate As String = "UPDATE I_TRAINEE_EVENTS_UNITS SET QUALSCHEMEUNITID = @QUALSCHEMEUNITID,PercentageComplete = @PercentageComplete  WHERE(EVENTUNITID = @ID)"
                cmd.CommandType = CommandType.Text
                cmd.CommandText = strUpdate.ToString()
                cmd.Parameters.Clear()
                cmd.Parameters.AddWithValue("@QUALSCHEMEUNITID", QUALSCHEMEUNITID.SelectedValue)
                cmd.Parameters.AddWithValue("@PercentageComplete", PercentageComplete.Text)
                cmd.Parameters.AddWithValue("@ID", ID.ToString())
                cmd.Connection = con
                con.Open()
                cmd.ExecuteNonQuery()
            Catch ex As SqlException
                Dim errorMsg As String = "Error in Updating"
                errorMsg &= ex.Message
                Throw New Exception(errorMsg)
            Finally
                con.Close()
            End Try

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Lokesh B R

Hi,

Replace For loop with below FOREACH loop.

Use FindControl() to find.

For Each row As GridViewRow In GridView1.Rows
	If row.RowType = DataControlRowType.DataRow Then
		Try
			Dim ID = GridView1.DataKeys(row.RowIndex).Value

			' Change the DropDownList ID based on your requirement
			Dim QUALSCHEMEUNITID As DropDownList = DirectCast(row.FindControl("DropDownList57"), DropDownList)

			' Change the TextBox ID based on your requirement
			Dim PercentageComplete As TextBox = DirectCast(row.FindControl("txtPerComplete"), TextBox)

			Dim strUpdate As String = "UPDATE I_TRAINEE_EVENTS_UNITS SET QUALSCHEMEUNITID=@QUALSCHEMEUNITID, PercentageComplete=@PercentageComplete WHERE(EVENTUNITID=@ID)"
			cmd.CommandType = CommandType.Text
			cmd.CommandText = strUpdate.ToString()
			cmd.Parameters.Clear()
			cmd.Parameters.AddWithValue("@QUALSCHEMEUNITID", QUALSCHEMEUNITID.SelectedValue)
			cmd.Parameters.AddWithValue("@PercentageComplete", PercentageComplete.Text)
			cmd.Parameters.AddWithValue("@ID", ID.ToString())
			cmd.Connection = con
			con.Open()
			cmd.ExecuteNonQuery()
		Catch ex As SqlException
			Dim errorMsg As String = "Error in Updating"
			errorMsg += ex.Message
			Throw New Exception(errorMsg)
		Finally
			con.Close()
		End Try
	End If
Next

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ASKER

I'm getting an error now

Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

Line 294:
Line 295: Try
Line 296: Dim QUALSCHEMEID As DropDownList = TryCast(gvUnits.FooterRow.Cells(1).Controls(1), DropDownList)
Line 297: Dim PercentageComplete As Integer = 40
Line 298:

Hers the full code for the button click event.

    Protected Sub cmdUpateUnits_Click(sender As Object, e As EventArgs) Handles cmdUpateUnits.Click
        'Create sql connection and command
        Dim con As New SqlConnection(ConnectionString)
        Dim cmd As New SqlCommand()

        For Each row As GridViewRow In gvUnits.Rows
            If row.RowType = DataControlRowType.DataRow Then
                Try
                    Dim ID = gvUnits.DataKeys(row.RowIndex).Value

                    ' Change the DropDownList ID based on your requirement
                    Dim QUALSCHEMEUNITID As DropDownList = DirectCast(row.FindControl("DropDownList57"), DropDownList)

                    ' Change the TextBox ID based on your requirement
                    Dim PercentageComplete As TextBox = DirectCast(row.FindControl("txtPerComplete"), TextBox)

                    Dim strUpdate As String = "UPDATE I_TRAINEE_EVENTS_UNITS SET QUALSCHEMEUNITID=@QUALSCHEMEUNITID, PercentageComplete=@PercentageComplete WHERE(EVENTUNITID=@ID)"
                    cmd.CommandType = CommandType.Text
                    cmd.CommandText = strUpdate.ToString()
                    cmd.Parameters.Clear()
                    cmd.Parameters.AddWithValue("@QUALSCHEMEUNITID", QUALSCHEMEUNITID.SelectedValue)
                    cmd.Parameters.AddWithValue("@PercentageComplete", PercentageComplete.Text)
                    cmd.Parameters.AddWithValue("@ID", ID.ToString())
                    cmd.Connection = con
                    con.Open()
                    cmd.ExecuteNonQuery()
                Catch ex As SqlException
                    Dim errorMsg As String = "Error in Updating"
                    errorMsg += ex.Message
                    Throw New Exception(errorMsg)
                Finally
                    con.Close()
                End Try
            End If
        Next



        Try
            Dim QUALSCHEMEID As DropDownList = TryCast(gvUnits.FooterRow.Cells(1).Controls(1), DropDownList)
            Dim PercentageComplete As Integer = 40

            If QUALSCHEMEID.SelectedValue.ToString() <> "0"c.ToString() Then

                Dim strUpdate As String = "INSERT INTO I_TRAINEE_EVENTS_UNITS (QUALSCHEMEUNITID, EVENTID, PercentageComplete) VALUES(@QUALSCHEMEUNITID,@EVENTID,@PercentageComplete)"
                cmd.CommandType = CommandType.Text
                cmd.CommandText = strUpdate.ToString()
                cmd.Parameters.Clear()
                cmd.Parameters.AddWithValue("@EVENTID", dvEvent.SelectedValue)
                cmd.Parameters.AddWithValue("@QUALSCHEMEUNITID", QUALSCHEMEID.SelectedValue)
                cmd.Parameters.AddWithValue("@PercentageComplete", PercentageComplete.ToString)
                cmd.Connection = con
                con.Open()
                cmd.ExecuteNonQuery()
            End If
        Catch ex As SqlException
            Dim errorMsg As String = "Error in Insert"
            errorMsg &= ex.Message
            Throw New Exception(errorMsg)
        Finally
            con.Close()
        End Try

        gvUnits.DataBind()
    End Sub

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ASKER CERTIFIED SOLUTION

Lokesh B R

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ASKER

Great thanks.