Windows 7 theme for WPF?

Question

Is there any way to make a WPF app look like it's running on Windows 7 even if it's running on XP? I'm looking for some kind of theme I can just paste in. I'm aware of the themes project on Codeplex (http://www.codeplex.com/wpfthemes), but it lacks support for DataGrid, which is something I critically need. I was thinking maybe the Windows 7 theme would just be an easy port, or exists in some file somewhere already. Any information you have (even if it's bad news) would be much appreciated.

Update

Using @Lars Truijens idea, I was able to get the Windows 7 look for the major controls, but unfortunately it did not work for the WPF Toolkit DataGrid control, which I need.

DataGrid looks like this with Aero theme

DataGrid should look like this

So, I'm still looking for a solution to this problem if anyone has any ideas. Maybe someone has built an extension to the Aero theme that covers the WPF toolkit controls? Again, any information you have is much appreciated.

Update 2 - Problem solved!

To get the Aero theme to work with WPF Toolkit controls, you just need to add a second Aero dictionary, so your App.xaml should now look like this.

<Application.Resources>
    ...
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary
                Source="/PresentationFramework.Aero;component/themes/Aero.NormalColor.xaml" />
            <ResourceDictionary
                Source="pack://application:,,,/WPFToolkit;component/Themes/Aero.NormalColor.xaml" />
            ...
        </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
</Application.Resources>

Also, I would recommend turning the gridlines off in your DataGrid controls (because they look horrible):

<DataGrid  GridLinesVisibility="None" ...>

Answer 1

WPF comes with the standard Windows themes on all Windows versions. For example, you can have the Aero theme (which Vista and Windows 7 use) on Windows XP with the following steps:

1. Add PresentationFramework.Aero to your application's references list as a requires
2. Edit your App.xaml

from this

<Application.Resources>
  <!-- Your stuff here -->
</Application.Resources>

to this

<Application.Resources>
  <ResourceDictionary>
    <!-- Put your stuff here instead -->

    <ResourceDictionary.MergedDictionaries>
      <ResourceDictionary Source="/PresentationFramework.Aero;component/themes/Aero.NormalColor.xaml"/>
    </ResourceDictionary.MergedDictionaries>
  </ResourceDictionary>
</Application.Resources> 

Source: http://mrpmorris.blogspot.com/2008/05/using-vista-aero-theme-in-xp-wpf-apps.html

Other alternatives below. Be sure to add the corresponding assembly to your application's reference list as a requires.

<ResourceDictionary Source="/PresentationFramework.Aero;component/themes/Aero.NormalColor.xaml"/>
<ResourceDictionary Source="/PresentationFramework.Classic;component/themes/Classic.xaml"/>
<ResourceDictionary Source="/PresentationFramework.Royale;component/themes/Royale.NormalColor.xaml"/>
<ResourceDictionary Source="/PresentationFramework.Luna.Homestead;component/themes/Luna.Homestead.xaml"/>
<ResourceDictionary Source="/PresentationFramework.Luna.Metallic;component/themes/Luna.Metallic.xaml"/>
<ResourceDictionary Source="/PresentationFramework.Zune;component/themes/Zune.NormalColor.xaml"/>

Answer 2

Just for the record, there's a stunning Windows 7 theme in Xceed Pro Themes for WPF that styles all official Microsoft WPF 3.5 and 4.0 controls including the WPF Datagrid and datepicker.

Xceed Pro Themes for WPF