DataGridTemplateColumn : Items collection must be empty before using ItemsSource.
Keep template column inside DataGrid.Columns.
<dg:DataGrid Name="dataGrid" AutoGenerateColumns="False" HeadersVisibility="Column" SelectedIndex="-1" Margin="0,315,0,0" Background="#FF484040" BorderBrush="#FF484040"> <dg:DataGrid.Columns> <dg:DataGridTextColumn Binding="{Binding IdBook}" Header="IdBook"></dg:DataGridTextColumn> <dg:DataGridTextColumn Binding="{Binding NameBook}" Header="NameBook"></dg:DataGridTextColumn> <dg:DataGridTextColumn Binding="{Binding Author}" Header="Author"></dg:DataGridTextColumn> <dg:DataGridTemplateColumn Header="Delete"> <dg:DataGridTemplateColumn.CellTemplate> <DataTemplate> <Button Style="{DynamicResource GlassButton}" Background="{DynamicResource DeleteButton}"> </Button> </DataTemplate> </dg:DataGridTemplateColumn.CellTemplate> </dg:DataGridTemplateColumn> </dg:DataGrid.Columns> </<dg:DataGrid>