DataGridのHeaderにBindすると"System.Windows.Data.Binding"が表示されて困ったので対処したときのメモ。

バインドするデータ

MainWindowViewModel.cs

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace SilverlightApplication4
{
    public class MainWindowViewModel
    {
        public string Header1
        {
            get {return "Test1" ; }
        }

        public string Header2
        {
            get {return "Test2" ; }
        }

        public string Header3
        {
            get {return "Test3" ; }
        }
    }
}

DataGridを持つ画面。右列が困った例。
左列がその対策

MainPage.xaml

<UserControl x:Class="SilverlightApplication4.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:my="clr-namespace:SilverlightApplication4"
    xmlns:data="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data"
xmlns:dataprimitives="clr-namespace:System.Windows.Controls.Primitives;assembly=System.Windows.Controls.Data"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">
    <UserControl.DataContext>
        <my:MainWindowViewModel x:Name="vm"></my:MainWindowViewModel>
    </UserControl.DataContext>

    <Grid x:Name="LayoutRoot" Background="White">
        <data:DataGrid>
            <data:DataGrid.Columns>
                <data:DataGridTextColumn>
                    <data:DataGridTextColumn.HeaderStyle>
                        <Style TargetType="dataprimitives:DataGridColumnHeader">
                            <Setter Property="Template">
                                <Setter.Value>
                                    <ControlTemplate>
                                        <TextBlock Text="{Binding Header1}" VerticalAlignment="Center" />
                                    </ControlTemplate>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </data:DataGridTextColumn.HeaderStyle>
                </data:DataGridTextColumn>
                <data:DataGridTextColumn Header="Test2"></data:DataGridTextColumn>
                <data:DataGridTextColumn Header="Test3"></data:DataGridTextColumn>
                <data:DataGridTextColumn Header="{Binding Header1}"></data:DataGridTextColumn>
            </data:DataGrid.Columns>
        </data:DataGrid>
    </Grid>
</UserControl>