WPF icon的设置

想给控件设置个圆形图片，代码如下：

​<Setter Property="Icon"><Setter.Value><Image Source="/WpfApp1;component/Resource/1.ico" Width="16" Height="16"/></Setter.Value></Setter>​

报错，提示   expected type is ‘geometry’, actual type is ‘image’

改成如下：

      <Setter Property="Icon"><Setter.Value><EllipseGeometry Center="40,50" RadiusX="20" RadiusY="20"></EllipseGeometry></Setter.Value></Setter>