This example shows how to assign the combo box and spin editors to grid columns.
<Window x:Class="DXGrid_AssignComboBoxToColumn.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:dxe="http://schemas.devexpress.com/winfx/2008/xaml/editors"
xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid"
xmlns:local="clr-namespace:DXGrid_AssignComboBoxToColumn"
Title="Window1" Height="300" Width="499">
<Grid>
<dxg:GridControl x:Name="grid" ItemsSource="{x:Static local:NwindData.Data}">
<dxg:GridControl.Columns>
<dxg:GridColumn FieldName="ProductName"
EditSettings="{dxe:ComboBoxSettings DisplayMember=ProductName, ValueMember=ProductName, ItemsSource={x:Static local:NwindData.Data}}" />
<dxg:GridColumn FieldName="UnitPrice">
<dxg:GridColumn.EditSettings>
<dxe:SpinEditSettings MaxValue="999" MinValue="1" />
</dxg:GridColumn.EditSettings>
</dxg:GridColumn>
<dxg:GridColumn FieldName="Discontinued" />
</dxg:GridControl.Columns>
<dxg:GridControl.View>
<dxg:TableView AutoWidth="True" />
</dxg:GridControl.View>
</dxg:GridControl>
</Grid>
</Window>