How to stretch WPF DataGridColumn's header when create?

Question

I generate my columns dynamicaly and would like to stretch their headers, like here

In generall the columns can have different names so it is not possible to set a fixed MinWidth. Is it possible through changing the DataGrid.ColumnHeaderStyle to set somehing like horizontal margin for the header text? Here is my XAML:

<DataGrid x:Name="ResultDataGrid" Margin="2"
    ItemsSource="{Binding MyData, Mode=OneWay}"
    DisplayMemberPath="Persons"
    SelectedItem="{Binding SelectedPerson}"
    GridLinesVisibility="None" 
    AutoGenerateColumns="False" 
    CanUserAddRows="False" 
    CanUserDeleteRows="False" 
    CanUserReorderColumns="False"
    IsReadOnly="True"
    SelectionMode="Single"
    AllowDrop="True">
    <DataGrid.ColumnHeaderStyle>
        <Style TargetType="{x:Type DataGridColumnHeader}">
            <Setter Property="HorizontalContentAlignment" Value="Center" />
            <Setter Property="Height" Value="25" />
            <Setter Property="FontWeight" Value="Black" />
            <Setter Property="SeparatorBrush" Value="LightGray" />
        </Style>
    </DataGrid.ColumnHeaderStyle>
</DataGrid>     

Answer 1

You can add another Setter to your Style to change ContentTemplate to TextBlock with left/right margin set

<DataGrid.ColumnHeaderStyle>
   <Style TargetType="{x:Type DataGridColumnHeader}">
      <Setter Property="HorizontalContentAlignment" Value="Center" />
      <Setter Property="Height" Value="25" />
      <Setter Property="FontWeight" Value="Black" />
      <Setter Property="SeparatorBrush" Value="LightGray" />
      <Setter Property="ContentTemplate">
         <Setter.Value>
            <DataTemplate>
               <TextBlock Text="{Binding}" Margin="20,0"/>
            </DataTemplate>
         </Setter.Value>
      </Setter>
   </Style>
</DataGrid.ColumnHeaderStyle>