wpftoolkit/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/WatermarkTextBox/Implementation/WatermarkTextBox.cs

using System;
using System.Windows;
using System.Windows.Controls;

namespace Microsoft.Windows.Controls
{
    public class WatermarkTextBox : TextBox
    {
        #region Properties

        #region Watermark

        public static readonly DependencyProperty WatermarkProperty = DependencyProperty.Register("Watermark", typeof(object), typeof(WatermarkTextBox), new UIPropertyMetadata(null));
        public object Watermark
        {
            get { return (object)GetValue(WatermarkProperty); }
            set { SetValue(WatermarkProperty, value); }
        }

        #endregion //Watermark

        #region WatermarkTemplate

        public static readonly DependencyProperty WatermarkTemplateProperty = DependencyProperty.Register("WatermarkTemplate", typeof(DataTemplate), typeof(WatermarkTextBox), new UIPropertyMetadata(null));
        public DataTemplate WatermarkTemplate
        {
            get { return (DataTemplate)GetValue(WatermarkTemplateProperty); }
            set { SetValue(WatermarkTemplateProperty, value); }
        }       

        #endregion //WatermarkTemplate

        #endregion //Properties

        #region Constructors

        static WatermarkTextBox()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(WatermarkTextBox), new FrameworkPropertyMetadata(typeof(WatermarkTextBox)));
        }

        #endregion //Constructors
    }
}