using System;
using System.Collections.Generic;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
using System.ComponentModel;

namespace WpfApplication1
{
	/// <summary>
	/// Interaction logic for MainWindow.xaml
	/// </summary>
	public partial class MainWindow : Window
	{
		public MainWindow()
		{
			this.InitializeComponent();

			// Insert code required on object creation below this point.

            this.Loaded += new RoutedEventHandler(MainWindow_Loaded);
		}

        void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            redButton.DataContext = new viewModelForButton(App.Current.Resources["redGradient"] as GradientBrush);
            blueButton.DataContext = new viewModelForButton(App.Current.Resources["blueGradient"] as GradientBrush);
        }

        
	}

    class viewModelForButton : INotifyPropertyChanged
    {
        private System.Windows.Media.GradientBrush gradientBrush;

        public System.Windows.Media.GradientBrush GradientBrush
        {
            get { return gradientBrush; }
            set
            {
                gradientBrush = value;
                onPropertyChanged("GradientBrush");
            }
        }

        public viewModelForButton(System.Windows.Media.GradientBrush gradientBrush)
        {
            // TODO: Complete member initialization
            this.gradientBrush = gradientBrush;
        }

        public event PropertyChangedEventHandler PropertyChanged;

        public void onPropertyChanged(String nameOfProp)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(nameOfProp));
        }
    }
}

<Window
	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
	x:Class="WpfApplication1.MainWindow"
	x:Name="Window"
	Title="MainWindow"
	Width="640" Height="480">

	<Grid x:Name="LayoutRoot">
		<Button x:Name="redButton" Content="Button" HorizontalAlignment="Left" VerticalAlignment="Top" Width="75" Background="{Binding GradientBrush}"/>
		<Button x:Name="blueButton" Content="Button" HorizontalAlignment="Left" VerticalAlignment="Top" Width="75" Margin="0,25.96,0,0" Background="{Binding GradientBrush}"/>
	</Grid>
</Window>