如何使用从.xaml中的TabControl继承的类？

我想在TabControl的顶部添加一个“新”按钮，如下所示：

因此，我创建了一个从TabControl继承的MyTabControl类：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Controls;
using System.Windows;
using System.ComponentModel;

namespace tabcontrol
{
    [TemplatePart(Name="PART_ExtraHeaderHost", Type=typeof(ContentPresenter))]
    public class MyTabControl : TabControl
    {
        #region Fields
        private const string ExtraHeaderHostTemplateName = "PART_ExtraHeaderHost";
        public static readonly DependencyProperty ExtraHeaderProperty = ExtraHeaderPropertyKey.DependencyProperty;
        private static readonly DependencyPropertyKey ExtraHeaderPropertyKey = DependencyProperty.RegisterReadOnly("ExtraHeader", typeof(object), typeof(TabControl), new FrameworkPropertyMetadata(null));
        public static readonly DependencyProperty ExtraHeaderStringFormatProperty = ExtraHeaderStringFormatPropertyKey.DependencyProperty;
        private static readonly DependencyPropertyKey ExtraHeaderStringFormatPropertyKey = DependencyProperty.RegisterReadOnly("ExtraHeaderStringFormat", typeof(string), typeof(TabControl), new FrameworkPropertyMetadata(null));
        public static readonly DependencyProperty ExtraHeaderTemplateProperty = ExtraHeaderTemplatePropertyKey.DependencyProperty;
        private static readonly DependencyPropertyKey ExtraHeaderTemplatePropertyKey = DependencyProperty.RegisterReadOnly("ExtraHeaderTemplate", typeof(DataTemplate), typeof(TabControl), new FrameworkPropertyMetadata(null));
        public static readonly DependencyProperty ExtraHeaderTemplateSelectorProperty = ExtraHeaderTemplateSelectorPropertyKey.DependencyProperty;
        private static readonly DependencyPropertyKey ExtraHeaderTemplateSelectorPropertyKey = DependencyProperty.RegisterReadOnly("ExtraHeaderTemplateSelector", typeof(DataTemplateSelector), typeof(TabControl), new FrameworkPropertyMetadata(null));

        #endregion Fields

        #region Properties
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public object ExtraHeader
        {
            get
            {
                return base.GetValue(ExtraHeaderProperty);
            }
            internal set
            {
                base.SetValue(ExtraHeaderPropertyKey, value);
            }
        }

        internal ContentPresenter ExtraHeaderPresenter
        {
            get
            {
                return (base.GetTemplateChild("PART_ExtraHeaderHost") as ContentPresenter);
            }
        }

        public string ExtraHeaderStringFormat
        {
            get
            {
                return (string)base.GetValue(ExtraHeaderStringFormatProperty);
            }
            internal set
            {
                base.SetValue(ExtraHeaderStringFormatPropertyKey, value);
            }
        }

        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public DataTemplate ExtraHeaderTemplate
        {
            get
            {
                return (DataTemplate)base.GetValue(ExtraHeaderTemplateProperty);
            }
            internal set
            {
                base.SetValue(ExtraHeaderTemplatePropertyKey, value);
            }
        }

        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public DataTemplateSelector ExtraHeaderTemplateSelector
        {
            get
            {
                return (DataTemplateSelector)base.GetValue(ExtraHeaderTemplateSelectorProperty);
            }
            internal set
            {
                base.SetValue(ExtraHeaderTemplateSelectorPropertyKey, value);
            }
        }


        #endregion Properties
    }
}

PART_ExtraHeaderHost放置“新”按钮。考虑到以后放置其他控件，因此请使用PART_ExtraHeaderHost而不是Button。

但是现在，我不知道如何使用它并设置样式？