Default.aspx.vb

Imports System
Imports System.Data
Imports DevExpress.Web

Namespace Solution

    Public Partial Class [Default]
        Inherits Web.UI.Page

        Private Function GetTable() As DataTable
            'You can store a DataTable in the session state
            Dim table As DataTable = TryCast(Session("Table"), DataTable)
            If table Is Nothing Then
                table = New DataTable()
                Dim colid As DataColumn = table.Columns.Add("ID", GetType(Integer))
                Dim nameid As DataColumn = table.Columns.Add("Name", GetType(String))
                table.PrimaryKey = New DataColumn() {colid}
                colid.ReadOnly = True
                For i As Integer = 0 To 23 - 1
                    Dim aRow As DataRow = table.NewRow()
                    aRow("ID") = i
                    aRow("Name") = String.Format("Name{0}", i)
                    table.Rows.Add(aRow)
                Next

                Session("Table") = table
            End If

            Return table
        End Function

        Public Function GetLastKey() As Integer
            Dim table As DataTable = GetTable()
            Dim max As Integer = Integer.MinValue
            For Each row As DataRow In table.Rows
                If Convert.ToInt32(row("ID")) > max Then max = Convert.ToInt32(row("ID"))
            Next

            Return max
        End Function

        Protected Sub Page_Init(ByVal sender As Object, ByVal e As EventArgs)
            grid.DataSource = GetTable()
            grid.KeyFieldName = "ID"
            grid.DataBind()
        End Sub

        Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
        End Sub

        Protected Sub grid_RowDeleting(ByVal sender As Object, ByVal e As DevExpress.Web.Data.ASPxDataDeletingEventArgs)
            Dim grid As ASPxGridView = TryCast(sender, ASPxGridView)
            Dim table As DataTable = GetTable()
            Dim found As DataRow = table.Rows.Find(e.Keys(0))
            table.Rows.Remove(found)
            Session("Table") = table
            e.Cancel = True
        End Sub

        Protected Sub grid_RowInserting(ByVal sender As Object, ByVal e As DevExpress.Web.Data.ASPxDataInsertingEventArgs)
            Dim grid As ASPxGridView = TryCast(sender, ASPxGridView)
            Dim table As DataTable = GetTable()
            table.Rows.Add(New Object() {e.NewValues("ID"), e.NewValues("Name")})
            Session("Table") = table
            e.Cancel = True
            grid.CancelEdit()
        End Sub

        Protected Sub grid_RowUpdating(ByVal sender As Object, ByVal e As DevExpress.Web.Data.ASPxDataUpdatingEventArgs)
            Dim grid As ASPxGridView = TryCast(sender, ASPxGridView)
            Dim table As DataTable = GetTable()
            Dim found As DataRow = table.Rows.Find(e.Keys(0))
            found("Name") = e.NewValues("Name")
            Session("Table") = table
            e.Cancel = True
            grid.CancelEdit()
        End Sub

        Protected Sub grid_InitNewRow(ByVal sender As Object, ByVal e As DevExpress.Web.Data.ASPxDataInitNewRowEventArgs)
            e.NewValues("ID") = GetLastKey() + 1
        End Sub
    End Class
End Namespace