Dynamically setting the Header text of a Silverlight DataGrid Column

My workaround was to use an attached property to set the binding automatically:

public static class DataGridColumnHelper
{
    public static readonly DependencyProperty HeaderBindingProperty = DependencyProperty.RegisterAttached(
        "HeaderBinding",
        typeof(object),
        typeof(DataGridColumnHelper),
        new PropertyMetadata(null, DataGridColumnHelper.HeaderBinding_PropertyChanged));

    public static object GetHeaderBinding(DependencyObject source)
    {
        return (object)source.GetValue(DataGridColumnHelper.HeaderBindingProperty);
    }

    public static void SetHeaderBinding(DependencyObject target, object value)
    {
        target.SetValue(DataGridColumnHelper.HeaderBindingProperty, value);
    }

    private static void HeaderBinding_PropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        DataGridColumn column = d as DataGridColumn;

        if (column == null) { return; }

        column.Header = e.NewValue;
    }
}

Then, in the XAML:

<data:DataGridTextColumn util:DataGridColumnHelper.HeaderBinding="{Binding MeetingName, Source={StaticResource LocStrings}}" />

To keep the visual styling from the original header, use ContentTemplate instead of Template:

<Setter Property="ContentTemplate">
<Setter.Value>
    <DataTemplate>
        <Image Source="<image url goes here>"/>
    </DataTemplate>
</Setter.Value>

Found an interesting workaround that also works with the wpflocalizeaddin.codeplex.com:

Created by Slyi

It uses an IValueConverter:

public class BindingConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        if (value.GetType().Name == "Binding")
        {
            ContentControl cc = new ContentControl();
            cc.SetBinding(ContentControl.ContentProperty, value as Binding);
            return cc;
        }
        else return value;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {

        return null;
    }
}

And a style for the DataGridColumnHeader

<UserControl.Resources>
    <local:BindingConverter x:Key="BindCon"/>
    <Style x:Key="ColBinding" TargetType="dataprimitives:DataGridColumnHeader" >
        <Setter Property="ContentTemplate" >
            <Setter.Value>
                <DataTemplate>
                    <ContentPresenter Content="{Binding Converter={StaticResource BindCon}}"  />
                </DataTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</UserControl.Resources>

so that you can keep your favorite binding syntax on the Header attribute

<Grid x:Name="LayoutRoot" Background="White">
    <StackPanel>
        <TextBox Text="binding header" x:Name="tbox" />

        <data:DataGrid ItemsSource="{Binding AllPeople,Source={StaticResource folks}}" AutoGenerateColumns="False" ColumnHeaderStyle="{StaticResource ColBinding}"  >
            <data:DataGrid.Columns>
                <data:DataGridTextColumn Binding="{Binding ID}" 

                                         Header="{Binding Text, ElementName=tbox}" />
                <data:DataGridTextColumn Binding="{Binding Name}" 

                                         Header="hello" />
            </data:DataGrid.Columns>
        </data:DataGrid>
    </StackPanel>

</Grid>

http://cid-289eaf995528b9fd.skydrive.live.com/self.aspx/Public/HeaderBinding.zip

It does seem much simpler to set the value in code, as mentioned above:

dg1.Columns[3].Header = SomeDynamicValue;

Avoids using the Setter Property syntax, which in my case seemed to mess up the styling, even though I did try using ContentTemplate as well as Template.

One point I slipped up on was that it is better to use the dg1.Columns[3].Header notation rather than trying to reference a named column.

I had named one of my columns and tried to reference that in code but got null exceptions. Using the Columns[index] method worked well, and I could assign the Header a text string based on localization resources.

Why not simply set this in code:

dg1.Columns[3].Header = SomeDynamicValue;

Please note in solution provided by RobSiklos, Source {staticResource...} is the Key, if you plan to pass the RelativeSource like

Binding DataContext.SelectedHistoryTypeItem,RelativeSource={RelativeSource AncestorType=sdk:DataGrid},

it may not work

I got some solution for the binding. Since you use DataGridTemlateColumn, subclass it and add a property of type Binding named for instance "HeaderBinding". Now you can bind to that property from the XAML. Next, you should propagate the binding to the TextBlock in the DataTemplate of your header. For instance, you can do it with OnLoaded event of that TextBlock.

 HeaderTextBlock.SetBinding(TextBlock.TextProperty, HeaderBinding);

That's it. If you have more columns and want to use only one DataTemplate then it's a bit more complicated, but the idea is the same.