WPF中 ToggleButton的问题

我现在想做一个ToggleButton控件。 它有6种图片 表示 6个状态，
1 Unchecked, Normal
2 Unchecked，MouseOver 
3 Unchecked, Pressed
4 Checked， Normal
5 Checked, MouseOver
6 Checked, Pressed
现在换图片时通过用Setter 更改图片的Source 但是我不知道如何既表示MouseOver同时也可以知道他是Checked的状态。不知道事件触发那里该怎么写namespace MyDemo
{
    public class ImageToggleButton : ToggleButton
    {
        static ImageToggleButton()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(ImageToggleButton), new FrameworkPropertyMetadata(typeof(ImageToggleButton)));            Check_NormalStateProperty = DependencyProperty.Register("Check_NormalState", typeof(string), typeof(ImageToggleButton));
            Check_MouseOverStateProperty = DependencyProperty.Register("Check_MouseOverState", typeof(string), typeof(ImageToggleButton));
            Check_PressedStateProperty = DependencyProperty.Register("Check_PressedState", typeof(string), typeof(ImageToggleButton));            Uncheck_NormalStateProperty = DependencyProperty.Register("Uncheck_NormalState", typeof(string), typeof(ImageToggleButton));
            Uncheck_MouseOverStateProperty = DependencyProperty.Register("Uncheck_MouseOverState", typeof(string), typeof(ImageToggleButton));
            Uncheck_PressedStateProperty = DependencyProperty.Register("Uncheck_PressedState", typeof(string), typeof(ImageToggleButton));
        }        public string Check_NormalState
        {
            get { return (string)GetValue(Check_NormalStateProperty); }
            set { SetValue(Check_NormalStateProperty, value); }
        }        public string Check_MouseOverState
        {
            get { return (string)GetValue(Check_MouseOverStateProperty); }
            set { SetValue(Check_MouseOverStateProperty, value); }
        }        public string Check_PressedState
        {
            get { return (string)GetValue(Check_PressedStateProperty); }
            set { SetValue(Check_PressedStateProperty, value); }
        }        public string Uncheck_NormalState
        {
            get { return (string)GetValue(Uncheck_NormalStateProperty); }
            set { SetValue(Uncheck_NormalStateProperty, value); }
        }        public string Uncheck_MouseOverState
        {
            get { return (string)GetValue(Uncheck_MouseOverStateProperty); }
            set { SetValue(Uncheck_MouseOverStateProperty, value); }
        }        public string Uncheck_PressedState
        {
            get { return (string)GetValue(Uncheck_PressedStateProperty); }
            set { SetValue(Uncheck_PressedStateProperty, value); }
        }        public static DependencyProperty Check_NormalStateProperty;
        public static DependencyProperty Check_MouseOverStateProperty;
        public static DependencyProperty Check_PressedStateProperty;        public static DependencyProperty Uncheck_NormalStateProperty;
        public static DependencyProperty Uncheck_MouseOverStateProperty;
        public static DependencyProperty Uncheck_PressedStateProperty;
    }
}
    <Style TargetType="{x:Type local:ImageToggleButton}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type local:ImageToggleButton}">
                    <Border>
                        <Image Name="imgground" Source="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=(local:ImageToggleButton.Uncheck_NormalState)}" Stretch="Fill"/>
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsChecked" Value="True">
                            <Setter TargetName="imgground" Property="Source" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=(local:ImageToggleButton.Check_NormalState)}"/>
                        </Trigger>
                        <Trigger Property="IsMouseOver" Value="True" >
                            <Setter TargetName="imgground" Property="Source" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=(local:ImageToggleButton.Check_MouseOverState)}"/>
                        </Trigger>
                        <Trigger Property="IsPressed" Value="True">
                            <Setter TargetName="imgground" Property="Source" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=(local:ImageToggleButton.Check_PressedState)}"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
不知道<ControlTemplate.Triggers>里面该怎么写