Webgrid in a WebTab causes Microsoft JScript runtime error: 'null' is null or not an object error.

handy@intersoftpt.com — Mon, 29 Nov 2010 10:22:04 GMT

Hello Jason,

Please see my attachment sample. The WebGrid binds dynamically from button. it is also placed inside WebTab. Everything works well. Perhaps, you can refer into my sample.

Also, Please try to use the latest hotfixes for the best result (WebGrid, WebDesktop, WebUIFramework).

Regards,
Handy

Webgrid in a WebTab causes Microsoft JScript runtime error: 'null' is null or not an object error.

jasonw43 — Thu, 25 Nov 2010 19:16:31 GMT

I have a web grid inside a Webtab. The webgrid's datasource changes depending on a button click (different tables for each button).

This works beautifully when sitting in a page by itself, however the minute I place it in a WebTab, I get problems whenever I click on a control that does a post back (the error being Microsoft JScript runtime error: 'null' is null or not an object).

Here is the aspx page.

<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Master.aspx.vb" Inherits="SCLSalesOrderForm.Master" %>

<%@ Register Assembly="ISNet.WebUI.WebDesktop" Namespace="ISNet.WebUI.WebDesktop"
    TagPrefix="ISWebDesktop" %>
<%@ Register Assembly="ISNet.WebUI.WebGrid" Namespace="ISNet.WebUI.WebGrid" TagPrefix="ISWebGrid" %>
<html>
<head id="Head1" runat="server">
    <title>Master Page</title>
    <link rel="stylesheet" type="text/css" href="../global.css" />
    <meta http-equiv="Pragma" content="no-cache" />
    <meta http-equiv="Expires" content="-1" />
    <meta http-equiv="CACHE-CONTROL" content="NO-CACHE" />
</head>
<body id="Body1" runat="server">
    <form id="Form1" runat="server" style="height: 552px">
    <div>
        <ISWebDesktop:WebTab ID="WebTab1" runat="server" Height="600px" Width="800px">
            <TabPages>
                <ISWebDesktop:WebTabItem Text="Tab 1">
                    <PageTemplate>
                        <div>
                            <br />
                            <asp:Table ID="Table2" runat="server">
                                <asp:TableRow>
                                    <asp:TableCell>
                                        <asp:Button ID="btnCustomer" runat="server" Text="Customer Lookup" />
                                    </asp:TableCell>
                                    <asp:TableCell>
                                        <asp:Button ID="btnSales" runat="server" Text="Sales Order Lookup" />
                                    </asp:TableCell>
                                    <asp:TableCell>
                                        <asp:Button ID="btnProcess" runat="server" Text="Process Sales Order" />
                                    </asp:TableCell>
                                </asp:TableRow>
                            </asp:Table>
                            <br />
                            <ISWebGrid:WebGrid ID="grdWebGrid1" runat="server" Height="500px" UseDefaultStyle="true"
                                DefaultStyleMode="Win7" HorizontalAlign="NotSet" OnInitializeRow="grdWebGrid1_InitializeRow"
                                OnInitializeDataSource="grdWebGrid1_InitializeDataSource" OnPrepareDataBinding="grdWebGrid1_PrepareDataBinding"
                                Width="790px">
                                <FlyPostBackSettings PostInputControls="True" />
                                <RootTable DataKeyField="" GridLineStyle="NotSet" Caption="Valuations">
                                </RootTable>
                                <LayoutSettings AllowAddNew="No" AllowDelete="No" AllowColumnMove="Yes" AllowEdit="No"
                                    AllowExport="Yes" AllowFilter="Yes" AllowGrouping="Yes" AllowSelectColumns="Yes"
                                    AllowSorting="Yes">
                                </LayoutSettings>
                            </ISWebGrid:WebGrid>
                        </div>
                    </PageTemplate>
                </ISWebDesktop:WebTabItem>
                <ISWebDesktop:WebTabItem Text="Tab 2">
                    <PageTemplate>
                        <div>
                            Test Tab 2
                        </div>
                    </PageTemplate>
                </ISWebDesktop:WebTabItem>
                <ISWebDesktop:WebTabItem Text="Tab 3">
                    <PageTemplate>
                        <div>
                            Test Tab 3
                        </div>
                    </PageTemplate>
                </ISWebDesktop:WebTabItem>
            </TabPages>
        </ISWebDesktop:WebTab>
        <asp:HiddenField ID="fldMode" runat="server" />
    </div>
    </form>
</body>
</html>

And here is the backend code.

BackEnd Code:

Imports System.IO
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.Management
Imports System.Web
Partial Public Class Master
    Inherits System.Web.UI.Page
    Dim mw As New MessageWindow

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not IsPostBack Then
            fldMode.Value = "Customer"
        End If

        WebTab1.ActiveTabIndex = Convert.ToInt16(fldTab.Value)

        grdWebGrid1.RebindDataSource()

    End Sub
    Protected Sub grdWebGrid1_InitializeDataSource(ByVal sender As Object, ByVal e As ISNet.WebUI.WebGrid.DataSourceEventArgs)

        Dim ds As New DataSet
        Dim DBConn As SqlConnection
        Dim da As SqlDataAdapter
        Dim DBSelect As String

        If fldMode.Value = "Customer" Then
            DBSelect = "Select [Customer], [Name], [CreditStatus] as 'Credit Status', [ShipToAddr3] as 'Suburb', [ShipToAddr4] as 'State', [Salesperson], [Contact] from [ArCustomer] ORDER BY [Customer] ASC"
            DBConn = New SqlConnection(ConfigurationManager.ConnectionStrings("SCL").ConnectionString)
            da = New SqlDataAdapter(DBSelect, DBConn)
            da.Fill(ds, "Customer")
            grdWebGrid1.RootTable.DataKeyField = "Customer"
        Else
            DBSelect = "Select [SalesOrder] as 'Sales Order', [OrderStatus] as 'Order Status', [Customer], [Salesperson], [CustomerPoNumber] as 'PO Number', [OrderDate] as 'Order Date' from [SorMaster] where ActiveFlag <> 'N'"
            DBConn = New SqlConnection(ConfigurationManager.ConnectionStrings("SCL").ConnectionString)
            da = New SqlDataAdapter(DBSelect, DBConn)
            da.Fill(ds, "SalesOrder")
            grdWebGrid1.RootTable.DataKeyField = "SalesOrder"
        End If

        e.DataSource = ds

    End Sub

    Protected Sub grdWebGrid1_PrepareDataBinding(ByVal sender As Object, ByVal e As ISNet.WebUI.WebGrid.DataSourceEventArgs)

        grdWebGrid1.RetrieveHierarchicalStructure()

    End Sub
    Protected Sub grdWebGrid1_InitializeRow(ByVal sender As Object, ByVal e As ISNet.WebUI.WebGrid.RowEventArgs) Handles grdWebGrid1.InitializeRow

        If grdWebGrid1.RootTable.DataKeyField = "SalesOrder" Then
            grdWebGrid1.RootTable.Columns.GetNamedItem("Order Date").DataFormatString = "dd/MM/yyyy"
        End If

    End Sub


    Private Sub btnSales_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSales.Click

        fldMode.Value = "SalesOrder"
        Dim ds As New DataSet
        Dim DBConn As SqlConnection
        Dim da As SqlDataAdapter
        Dim DBSelect As String

        DBSelect = "Select [SalesOrder] as 'Sales Order', [OrderStatus] as 'Order Status', [Customer], [Salesperson], [CustomerPoNumber] as 'PO Number', [OrderDate] as 'Order Date' from [SorMaster] where ActiveFlag <> 'N'"
        DBConn = New SqlConnection(ConfigurationManager.ConnectionStrings("SCL").ConnectionString)
        da = New SqlDataAdapter(DBSelect, DBConn)
        da.Fill(ds, "SalesOrder")
        grdWebGrid1.RootTable.DataKeyField = "SalesOrder"
        grdWebGrid1.Width = 650
        grdWebGrid1.DataSource = ds
        grdWebGrid1.RebindDataSource()

    End Sub

    Private Sub btnCustomer_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnCustomer.Click

        Dim ds As New DataSet
        Dim DBConn As SqlConnection
        Dim da As SqlDataAdapter
        Dim DBSelect As String

        fldMode.Value = "Customer"
        DBSelect = "Select [Customer], [Name], [CreditStatus] as 'Credit Status', [ShipToAddr3] as 'Suburb', [ShipToAddr4] as 'State', [Salesperson], [Contact] from [ArCustomer] ORDER BY [Customer] ASC"
        DBConn = New SqlConnection(ConfigurationManager.ConnectionStrings("SCL").ConnectionString)
        da = New SqlDataAdapter(DBSelect, DBConn)
        da.Fill(ds, "Customer")
        grdWebGrid1.RootTable.DataKeyField = "Customer"
        grdWebGrid1.Width = 790

        grdWebGrid1.DataSource = ds
        grdWebGrid1.RebindDataSource()

    End Sub

    Private Sub btnProcess_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnProcess.Click

        Try
            Dim ThisKey As String
            Dim ThisRow As Integer
            Dim ThisMode As String

            ThisRow = grdWebGrid1.RetrieveClientLastSelectedObject().RowIndex
            ThisKey = Convert.ToString(grdWebGrid1.RootTable.Rows(ThisRow).Cells(0).Value)

            If ThisKey = "" Then
                Call mw.UserMsgBox("Please select an instruction to process.")
            Else
                If fldMode.Value = "Customer" Then
                    ThisMode = "Add"
                Else
                    ThisMode = "Update"
                End If

                Dim StringURL As String = "SorDetail.aspx?Mode=" & ThisMode & "&id=" & ThisKey
                Page.Response.Redirect(StringURL)
            End If
        Catch ex As Exception
            If fldMode.Value = "Customer" Then
                Call mw.UserMsgBox("Please select a customer to process.")
            Else
                Call mw.UserMsgBox("Please select a sales order to process.")
            End If

        End Try

    End Sub
End Class

If I initially click on the other tabs, I get the correct information displayed - the only problem seems to occur when I click on one of the buttons that sends a postback.

The version of WebDesktopManager is 3.0.7200.310 and the version of WebGrid is 7.0.7200.403.

Thanks,

Jason.

Intersoft Community - WebGrid Enterprise - Webgrid in a WebTab causes Microsoft JScript runtime error: 'null' is null or not an object error.

Webgrid in a WebTab causes Microsoft JScript runtime error: 'null' is null or not an object error.

Webgrid in a WebTab causes Microsoft JScript runtime error: 'null' is null or not an object error.