Where can I find the XAML template for a WPF DataGrid or a WPF control in general?

I would recommend going into Blend (if you have it) and extracting the Template. Otherwise, you can get the XAML using XAMLWriter.

This unfortunately named page (I don't think this is really "Kid's Stuff", do you?) has an example of doing both of these things.

In case the page does happen to go away (2009 is pretty far in the rear-view mirror):

// Get the template from the control
YourControlType ctl = new YourControlType();
ctl.UpdateDefaultStyle();
ControlTemplate template = ctl.Template;

// We want our xaml of be properly indented, ohterwise
// we would not be able to indent them.
XmlWriterSettings xmlSettings = new XmlWriterSettings();
xmlSettings.Indent = true;

// Make the string builder
StringBuilder sb = new StringBuilder();
XmlWriter writer = XmlWriter.Create(sb, xmlSettings);
XamlWriter.Save(template, writer);


// Now the sb.ToString() should give us the template

All credit to Shafqat Ahmed.

Here is what i got out of Blend 4:

<ControlTemplate TargetType="{x:Type DataGrid}">
                <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Padding="{TemplateBinding Padding}" SnapsToDevicePixels="True">
                    <ScrollViewer x:Name="DG_ScrollViewer" Focusable="false">
                        <ScrollViewer.Template>
                            <ControlTemplate TargetType="{x:Type ScrollViewer}">
                                <Grid>
                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition Width="Auto"/>
                                        <ColumnDefinition Width="*"/>
                                        <ColumnDefinition Width="Auto"/>
                                    </Grid.ColumnDefinitions>
                                    <Grid.RowDefinitions>
                                        <RowDefinition Height="Auto"/>
                                        <RowDefinition Height="*"/>
                                        <RowDefinition Height="Auto"/>
                                    </Grid.RowDefinitions>
                                    <Button Command="{x:Static DataGrid.SelectAllCommand}" Focusable="false" Style="{DynamicResource {ComponentResourceKey ResourceId=DataGridSelectAllButtonStyle, TypeInTargetAssembly={x:Type DataGrid}}}" Visibility="{Binding HeadersVisibility, ConverterParameter={x:Static DataGridHeadersVisibility.All}, Converter={x:Static DataGrid.HeadersVisibilityConverter}, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}" Width="{Binding CellsPanelHorizontalOffset, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"/>
                                    <DataGridColumnHeadersPresenter x:Name="PART_ColumnHeadersPresenter" Grid.Column="1" Visibility="{Binding HeadersVisibility, ConverterParameter={x:Static DataGridHeadersVisibility.Column}, Converter={x:Static DataGrid.HeadersVisibilityConverter}, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"/>
                                    <ScrollContentPresenter x:Name="PART_ScrollContentPresenter" CanContentScroll="{TemplateBinding CanContentScroll}" Grid.ColumnSpan="2" Grid.Row="1"/>
                                    <ScrollBar x:Name="PART_VerticalScrollBar" Grid.Column="2" Maximum="{TemplateBinding ScrollableHeight}" Orientation="Vertical" Grid.Row="1" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" Value="{Binding VerticalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportHeight}"/>
                                    <Grid Grid.Column="1" Grid.Row="2">
                                        <Grid.ColumnDefinitions>
                                            <ColumnDefinition Width="{Binding NonFrozenColumnsViewportHorizontalOffset, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"/>
                                            <ColumnDefinition Width="*"/>
                                        </Grid.ColumnDefinitions>
                                        <ScrollBar x:Name="PART_HorizontalScrollBar" Grid.Column="1" Maximum="{TemplateBinding ScrollableWidth}" Orientation="Horizontal" Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}" Value="{Binding HorizontalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportWidth}"/>
                                    </Grid>
                                </Grid>
                            </ControlTemplate>
                        </ScrollViewer.Template>
                        <ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                    </ScrollViewer>
                </Border>
            </ControlTemplate>

there are two great lists of templates/styles on msdn I often use:

http://msdn.microsoft.com/fr-fr/library/aa970773.aspx

http://msdn.microsoft.com/en-us/library/aa970773.aspx

sadly, they are not as advertised as they should be...

so as far as you are concerned, I'd recommend this (got it from the second link): http://msdn.microsoft.com/en-us/library/ff506248.aspx

helped me a lot recently!