Question: Is it possible to declare `DataGrid` columns in a style or as a resource?
I would like to do something like this:

```
<....Resources>
    <DataGridColumns x:Key="dgcDataGridColumns">
        <DataGridTextColumn />
        <DataGridTextColumn />
    </DataGridColumns
</....Resources>

<DataGrid Columns="{StaticResource dgcDataGridColumns}" />

```

The reason is that i have to share the column definition for 4 different `DataGrids`. Any way to achieve this? Best would be without code behind!

Answer: 
Columns property of the DataGrid has no setter so it is not possibly. You can however do something like this:

```
<Window.Resources>

    <Controls:DataGrid x:Key="PersonDataGrid" AutoGenerateColumns="False" ItemsSource="{Binding .}" x:Shared="False">
        <Controls:DataGrid.Columns>
            <Controls:DataGridTextColumn Header="First Name" Binding="{Binding Path=FirstName}" IsReadOnly="True"/>
            <Controls:DataGridTextColumn Header="Last Name" Binding="{Binding Path=LastName}" IsReadOnly="True"/>
        </Controls:DataGrid.Columns>
    </Controls:DataGrid>

</Window.Resources>

<StackPanel>
    <ContentControl Content="{StaticResource PersonDataGrid}" DataContext="{Binding Path=Customers}"></ContentControl>
    <ContentControl Content="{StaticResource PersonDataGrid}" DataContext="{Binding Path=Employees}"></ContentControl>
</StackPanel>

```
I don't think you can, as in that situation you aren't specifying a template or a style, but the actual Column object. I don't think the data grids play nicely when sharing like that; I think you'll get an exception to the extent of "This UIElement is already the child of another UIElement".

So I tried the following...slightly different than what you're talking about. but I got this exception:

{"DataGridColumn with Header '' already exists in the Columns collection of a DataGrid. DataGrids cannot share columns and cannot contain duplicate column instances.\r\nParameter name: item"}

with this XAML:

```
         <Grid.Resources>
            <DataGridTextColumn x:Key="MyColumn" />
        </Grid.Resources>
          <DataGrid>
            <DataGrid.Columns>
                <StaticResource ResourceKey="MyColumn" />
            </DataGrid.Columns>
        </DataGrid>

        <DataGrid>
            <DataGrid.Columns>
                <StaticResource ResourceKey="MyColumn" />
            </DataGrid.Columns>
        </DataGrid>

```