Override の設定

<ig:XamGrid x:Name="xamGrid1" AutoGenerateColumns="False">
   <!-- 列はデフォルトでは ReadOnly です -->
   <ig:XamGrid.Columns>
      <ig:TextColumn Key="CategoryName" />
      <ig:TextColumn Key="Description" />
   </ig:XamGrid.Columns>
   <ig:XamGrid.ColumnLayouts>
   <!-- 子列 -->
      <ig:ColumnLayout Key="Products">
         <!-- 子列で編集を許可します -->
         <ig:ColumnLayout.EditingSettings>
            <ig:EditingSettingsOverride AllowEditing="Row" />
         </ig:ColumnLayout.EditingSettings>
         <ig:ColumnLayout.Columns>
            <!-- 列のひとつで編集を制限します -->
            <ig:TextColumn Key="ProductName" IsReadOnly="True"/>
            <ig:TextColumn Key="QuantityPerUnit" />
            <ig:TextColumn Key="UnitPrice" />
         </ig:ColumnLayout.Columns>
      </ig:ColumnLayout>
   </ig:XamGrid.ColumnLayouts>
</ig:XamGrid>

Me.xamGrid1.ColumnLayouts(0).EditingSettings.AllowEditing = Infragistics.Controls.Grids.EditingType.Row
Dim productName As EditableColumn = TryCast(Me.xamGrid1.Columns.ColumnLayouts("Products").Columns("ProductName"), EditableColumn)
productName.IsReadOnly = True

this.xamGrid1.ColumnLayouts[0].EditingSettings.AllowEditing = Infragistics.Controls.Grids.EditingType.Row;
EditableColumn productName = this.xamGrid1.Columns.ColumnLayouts["Products"].Columns["ProductName"] as EditableColumn;
productName.IsReadOnly = true;