我有一个基类叫做Handle
我从中派生出几个基类,例如RectHandle
and EllipseHandle
。在这些子类中,我尝试覆盖默认样式键以指向Handle
但风格定位Handle
不适用。我仍然需要明确目标RectHandle
or EllipseHandle
直接或通过“BasedOn”样式。我缺少什么?
以下是 DefaultStyleKeyProperty 的 MSDN 摘录:
控件通常会将此属性的默认值覆盖为其自己的类型,但在某些情况下也可以使用主题字典中存在样式的基类型。
这是我的代码
public abstract class Handle : Shape
{
static Handle()
{
WidthProperty.OverrideMetadata(
typeof(Handle),
new FrameworkPropertyMetadata(10.0));
HeightProperty.OverrideMetadata(
typeof(Handle),
new FrameworkPropertyMetadata(10.0));
FillProperty.OverrideMetadata(
typeof(Handle),
new FrameworkPropertyMetadata(Brushes.Yellow));
StrokeProperty.OverrideMetadata(
typeof(Handle),
new FrameworkPropertyMetadata(Brushes.Gray));
StrokeThicknessProperty.OverrideMetadata(
typeof(Handle),
new FrameworkPropertyMetadata(2.0));
}
}
public class RectHandle : Handle
{
static RectHandle()
{
DefaultStyleKeyProperty.OverrideMetadata(
typeof(RectHandle),
new FrameworkPropertyMetadata(typeof(Handle)));
}
protected override Geometry DefiningGeometry
{
get
{
var origin = new Point(-RenderSize.Width / 2, -RenderSize.Height / 2);
var rect = new Rect(origin, RenderSize);
return new RectangleGeometry(rect);
}
}
}
public class EllipseHandle : Handle
{
static RectHandle()
{
DefaultStyleKeyProperty.OverrideMetadata(
typeof(EllipseHandle),
new FrameworkPropertyMetadata(typeof(Handle)));
}
protected override Geometry DefiningGeometry
{
get
{
var origin = new Point(-RenderSize.Width / 2, -RenderSize.Height / 2);
var rect = new Rect(origin, RenderSize);
return new EllipseGeometry(rect);
}
}
}
还有风格...
<Style TargetType="{x:Type annotations:Handle}">
<Setter Property="Stroke" Value="Red" />
</Style>
再说一遍,这是行不通的。
我的解决方法是基于第一个样式创建另外两种样式,但我认为这就是整个要点DefaultStyleKey
财产。
<Style TargetType="{x:Type annotations:Handle}">
<Setter Property="Stroke" Value="Red" />
</Style>
<Style TargetType="{x:Type annotations:RectHandle}"
BasedOn="{StaticResource {x:Type annotations:Handle}}" />
<Style TargetType="{x:Type annotations:EllipseHandle}"
BasedOn="{StaticResource {x:Type annotations:Handle}}" />