Dynamic Grid and Postback

[Jeff Ballard]

I am trying to figure out how to do what I need and seem to find examples for all the various aspects (save one) but can't pull it all together.  Here's what I am trying to do:

1. Programmatically build my grid with GridTemplateColumns (radio button lists, text boxes and dropdowns).  I've used these as an example: http://www.telerik.com/help/aspnet/grid/grdprogrammaticcreation.html.  I have no issue with creating the template columns - my columns get created.
2. Default the grid to edit mode at all times.  I used this example: http://www.telerik.com/help/aspnet/grid/grddefaulteditmodeforgriditemsoninitialload.html
3. The last item, and this is the part I haven't found an example for, is to have a button that is not a part of the grid or its associated ItemCommand that posts back and from that event get the changed items. Is this even possible?  The grid is really part of a larger form that needs to get saved when the save button is clicked.

What we are doing is creating a form/questionnaire for users to fill out that is dynamically built based on metadata from the database, hence everything being done programatically.

The problem I am running into occurs after page is posted back.  When the page posts back, the grid is set to nothing (this is VB) until it gets recreated in code.  After I define the grid structure in the PreInit event the Page Load event fires (I don't rebind at this point, I don't want to overwrite any changed values), but I can't see my edited values.  I thought that the grid would be loaded from view state by the time the page load event is done, but no luck.  Any ideas why I'm not seeing it?  My code is below.

Thanks,

Jeff

Imports Telerik.Web.UI

Partial Public Class _Default
    Inherits System.Web.UI.Page

    Protected WithEvents rgOne As RadGrid

    Private Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
        DefineGridStructure()
    End Sub

    Private Sub rgOne_NeedDataSource(ByVal sender As Object, ByVal e As GridNeedDataSourceEventArgs) Handles rgOne.NeedDataSource

        rgOne = CType(sender, RadGrid)

        Dim newTable As DataTable = New DataTable()

        Dim dc1 As New DataColumn

        dc1.ColumnName = "ColumnA"
        dc1.DataType = Type.GetType("System.String")
        newTable.Columns.Add(dc1)

        Dim row1 As DataRow = newTable.NewRow()
        row1.Item("ColumnA") = "Row 1 Value, Column A"

        Dim row2 As DataRow = newTable.NewRow()
        row2.Item("ColumnA") = "Row 2 Value, Column A"

        newTable.Rows.Add(row1)
        newTable.Rows.Add(row2)

        rgOne.DataSource = newTable

    End Sub

    Private Sub DefineGridStructure()

        rgOne = New RadGrid()

        rgOne.AllowMultiRowEdit = True
        rgOne.AutoGenerateColumns = False
        rgOne.AutoGenerateEditColumn = False
        rgOne.MasterTableView.EnableColumnsViewState = True
        rgOne.EnableViewState = True

        Dim templateBox As New TemplateTextBox("textOne")
        Dim templateColumn As New GridTemplateColumn()
        templateColumn.EditItemTemplate = templateBox
        templateColumn.DataField = "ColumnA"
        templateColumn.HeaderText = "Column A"

        rgOne.Columns.Add(templateColumn)

        ph1.Controls.Add(rgOne)

    End Sub

    Private Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not Page.IsPostBack Then
            rgOne.Rebind()
        Else
            For Each editedItem As GridEditableItem In rgOne.EditItems
                Dim newValues As New Hashtable()
                rgOne.MasterTableView.ExtractValuesFromItem(newValues, editedItem)
            Next
        End If
    End Sub

    Private Sub Page_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRender
        For Each dataItem As GridDataItem In rgOne.Items
            dataItem.Edit = True
        Next
        rgOne.Rebind()
    End Sub
End Class

Class TemplateTextBox
    Implements IBindableTemplate

    Private m_CtrlName As String

    Public Sub New(ByVal ctrlName As String)
        MyBase.New()
        m_CtrlName = ctrlName
    End Sub

    Public Function ExtractValues(ByVal container As System.Web.UI.Control) As System.Collections.Specialized.IOrderedDictionary Implements System.Web.UI.IBindableTemplate.ExtractValues
        Dim od As New OrderedDictionary
        Return od
    End Function

    Public Sub InstantiateIn(ByVal container As System.Web.UI.Control) Implements System.Web.UI.ITemplate.InstantiateIn
        Dim box As New RadTextBox()
        box.ID = m_CtrlName
        container.Controls.Add(box)
    End Sub
End Class

[Pavlina]

Hi Jeff,

Look at the following article for more information about how to force several grid items in edit mode and then update them on single button click.

Additionnally, I suggest that you try to change your code as it is shown bellow:
VB:

Imports Telerik.Web.UI

Partial Public Class _Default
    Inherits System.Web.UI.Page

    Protected WithEvents rgOne As RadGrid

    Private Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
        DefineGridStructure()
    End Sub

    Private Sub rgOne_NeedDataSource(ByVal sender As Object, ByVal e As GridNeedDataSourceEventArgs) Handles rgOne.NeedDataSource

        rgOne = CType(sender, RadGrid)

        Dim newTable As DataTable = New DataTable()

        Dim dc1 As New DataColumn

        dc1.ColumnName = "ColumnA"
        dc1.DataType = Type.GetType("System.String")
        newTable.Columns.Add(dc1)

        Dim row1 As DataRow = newTable.NewRow()
        row1.Item("ColumnA") = "Row 1 Value, Column A"

        Dim row2 As DataRow = newTable.NewRow()
        row2.Item("ColumnA") = "Row 2 Value, Column A"

        newTable.Rows.Add(row1)
        newTable.Rows.Add(row2)

        rgOne.DataSource = newTable

    End Sub

    Private Sub DefineGridStructure()

        rgOne = New RadGrid()

        rgOne.AllowMultiRowEdit = True
        rgOne.AutoGenerateColumns = False
        rgOne.AutoGenerateEditColumn = False
        rgOne.MasterTableView.EnableColumnsViewState = True
        rgOne.EnableViewState = True

        Dim templateBox As New TemplateTextBox("textOne")
        Dim templateColumn As New GridTemplateColumn()
        templateColumn.EditItemTemplate = templateBox
        templateColumn.DataField = "ColumnA"
        templateColumn.HeaderText = "Column A"

        rgOne.Columns.Add(templateColumn)

        ph1.Controls.Add(rgOne)

    End Sub

  Protected Sub RadGrid1_ItemCreated(ByVal sender As Object, ByVal e As Telerik.WebControls.GridItemEventArgs) Handles RadGrid1.ItemCreated
         If (Not Page.IsPostBack AndAlso TypeOf e.Item Is GridEditableItem) Then
            e.Item.Edit = True
         End If
    End Sub

End Class

Class TemplateTextBox
    Implements IBindableTemplate

    Private m_CtrlName As String

    Public Sub New(ByVal ctrlName As String)
        MyBase.New()
        m_CtrlName = ctrlName
    End Sub

    Public Function ExtractValues(ByVal container As System.Web.UI.Control) As System.Collections.Specialized.IOrderedDictionary Implements System.Web.UI.IBindableTemplate.ExtractValues
        Dim od As New OrderedDictionary
        Return od
    End Function

    Public Sub InstantiateIn(ByVal container As System.Web.UI.Control) Implements System.Web.UI.ITemplate.InstantiateIn
        Dim box As New RadTextBox()
        box.ID = m_CtrlName
        container.Controls.Add(box)
    End Sub
End Class

Kind regards,
Pavlina
the Telerik team

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