<Style TargetType="{x:Type local:ZoomPanel}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type local:ZoomPanel}">
                    <ItemsPresenter/>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
        
        <Setter Property="ItemTemplate">
            <Setter.Value>
                <loca:ZoomControl Scale="{Binding RelativeSource={RelativeSource AncestorType=local:ZoomPanel}, Path=Scale}"/>
            </Setter.Value>
        </Setter>
    </Style>

private double _scale = 1;
public double Scale
{
     get
     {
         return _scale;
     }
     set
     {
         _scale = value;
         NotifyPropertyChanged("Scale");       //通知Bind去改变子元素的Scale属性
     }
}

//子元素的Scale注册为依赖属性是因为要Bind到容器控件
public double Scale
{
       get { return (double)GetValue(ScaleProperty); }
       set
       {
              this.Height *= value;　　　　　　//问题出现在这里,容器的Scale通过Bind改变了子元素的Scale值时,这里居然没执行到,这样我就不能改变高度了.
              SetValue(ScaleProperty, value);
       }
}
        public static readonly DependencyProperty ScaleProperty = DependencyProperty.Register("Scale", typeof(double), typeof(ZoomControl), new UIPropertyMetadata(1.0));