I should add xamTextEditor column to xamDataGrid . i used  CellValuePresenter.

<

Style x:Key="SalesPrice_CellValuePresenterStyle" TargetType="{x:Type igDP:CellValuePresenter}" >

<Style.Resources>

<DataTemplate x:Key="SalesPriceStyleNoDataTemplate">

<igEditors:XamNumericEditor Value="{Binding Path =Host.Record.DataItem.SalesPrice.OldValue}" />

</DataTemplate>

</Style.Resources>

<Setter Property="ContentTemplate" Value="{StaticResource SalesPriceStyleNoDataTemplate}"/>

</Style>

and my gridfield difinition is

<igDP:Field Name="SalesPrice" Label="Sales Price" Width="Auto" >

<igDP:Field.Settings>

<igDP:FieldSettings EditorType="{x:Type igEditors:XamTextEditor}" AllowEdit="True" EditAsType="{x:Type System:Decimal}"

CellValuePresenterStyle="{StaticResource SalesPrice_CellValuePresenterStyle}" />

</igDP:Field.Settings>

the problem is new row is not added.  i added the tags also

<igDP:XamDataGrid.FieldLayoutSettings>

<igDP:FieldLayoutSettings AutoGenerateFields="False" SelectionTypeRecord="Single"

AddNewRecordLocation="OnBottom" AllowAddNew="True"

AllowDelete="True"  HighlightAlternateRecords="True"/>

</igDP:XamDataGrid.FieldLayoutSettings>

</igDP:Field>