Set a padding on dataGridCells in WPF

simple question: How can I set a padding on a dataGridCell in WPF? (either one at a time or on all cells, I don't care)

I have tried using the DataGrid.CellStyle property by adding a setter on the DataGridCell.Padding property as well as using the DataGridColumn.CellStyle property in the same way with no effect.

I also tried using the DataGridColumn.ElementStyle property with no more luck.

I'm kind of stuck there, has anyone managed to get a padding applied on a dataGridCell?

NB: I'll add that no, I cannot use transparent borders to do this, since I already use the border properties for something else. I also cannot use the margin property (which seems to work, surprisingly enough) as I use the background property and I don't want any "blank" space between my cells.

The problem is that the Padding isn't transfered to the Border that's in the Template for DataGridCell. You can edit the Template and add the TemplateBinding for Padding

<DataGrid ...>
    <DataGrid.CellStyle>
        <Style TargetType="DataGridCell">
            <Setter Property="Padding" Value="20"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type DataGridCell}">
                        <Border Padding="{TemplateBinding Padding}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" SnapsToDevicePixels="True">
                            <ContentPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                        </Border>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </DataGrid.CellStyle>
    <!--...-->
</DataGrid>

Here's a cleaner method (my opinion) that combines the approach from David

<Resources>
    <Style x:Key="ColumnElementStyle" TargetType="TextBlock">
        <Setter Property="Margin" Value="5,0,10,0" />
    </Style>
</Resources>

then...

<DataGridTextColumn ElementStyle="{StaticResource ColumnElementStyle}" />
<DataGridTextColumn ElementStyle="{StaticResource ColumnElementStyle}" />

(in my case, my rows are readonly, so no EditingStyle)

Almost 5 years later, since this question seems to still be of use (it is still getting upvotes) and since it has been requested, here is the solution I used (with the ElementStyle) on a TextColumn (but you can do the same for any type of DataGridColumn):

I did it all in code behind:

class MyTextColumn : DataGridTextColumn
{
	public MyTextColumn()
	{
		ElementStyle = new Style(typeof(TextBlock));
		EditingElementStyle = new Style(typeof(TextBox));

		ElementStyle.Setters.Add(new Setter(FrameworkElement.MarginProperty, new Thickness(3)));
		EditingElementStyle.Setters.Add(new Setter(Control.PaddingProperty, new Thickness(0, 1, 0, 1)));
	}
}

But if you want to do it directly in xaml:

<DataGrid.Columns>
    <DataGridTextColumn>
        <DataGridTextColumn.ElementStyle>
            <Style TargetType="TextBlock">
                <Setter Property="Margin" Value="3"/>
            </Style>
        </DataGridTextColumn.ElementStyle>
        <DataGridTextColumn.EditingElementStyle>
            <Style TargetType="TextBox">
                <Setter Property="Padding" Value="0 1 0 1"/>
            </Style>
        </DataGridTextColumn.EditingElementStyle>
    </DataGridTextColumn>
</DataGrid.Columns>

You could also try changing

{Binding BindingValue, StringFormat={}{0:#0.0000}}

to

{Binding BindingValue, StringFormat={}{0:#0.0000 }}

Interestingly enough WPF's XAML {0:#0.0000 } will honor this extra space character in the format of the rendered control to move your values off of the edge of your grid columns.

<DataGrid.Columns>
      <DataGridTextColumn  MinWidth="100" Header="Changed by"  Width=""  Binding="{Binding Changedby}" IsReadOnly="True"  >
        <DataGridTextColumn.CellStyle>
          <Style TargetType="DataGridCell">
          <Setter Property="BorderThickness" Value="0"/>
          <Setter Property="Background" Value="Transparent" />
         <Setter Property="FrameworkElement.HorizontalAlignment"Value="Center"/>
          </Style>
      </DataGridTextColumn.CellStyle>
    </DataGridTextColumn>