// Handle attached property changed to automatically target and untarget UIElements and Brushes.
private static void OnIsTargetChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
var isAdding = (bool)e.NewValue;
if (isAdding)
{
if (obj is UIElement)
{
XamlLight.AddTargetElement(GetIdStatic(), obj as UIElement);
}
else if (obj is Brush)
{
XamlLight.AddTargetBrush(GetIdStatic(), obj as Brush);
}
}
else
{
if (obj is UIElement)
{
XamlLight.RemoveTargetElement(GetIdStatic(), obj as UIElement);
}
else if (obj is Brush)
{
XamlLight.RemoveTargetBrush(GetIdStatic(), obj as Brush);
}
}
}
protected override void OnConnected()
{
if (DesignMode.DesignModeEnabled)
{
return;
}
compositor = ElementCompositionPreview.GetElementVisual(Window.Current.Content as UIElement).Compositor;
var compositeEffect = new CompositeEffect()
{
Mode = CanvasComposite.Add
};
compositeEffect.Sources.Add(new BorderEffect()
{
Source = new CompositionEffectSourceParameter("backdrop"),
ExtendX = CanvasEdgeBehavior.Clamp,
ExtendY = CanvasEdgeBehavior.Clamp
});
compositeEffect.Sources.Add(new BorderEffect()
{
Source = new CompositionEffectSourceParameter("color"),
ExtendX = CanvasEdgeBehavior.Clamp,
ExtendY = CanvasEdgeBehavior.Clamp
});
var Brush = compositor.CreateEffectFactory(compositeEffect).CreateBrush();
Brush.SetSourceParameter("backdrop", compositor.CreateBackdropBrush());
Brush.SetSourceParameter("color", compositor.CreateColorBrush(Color));
CompositionBrush = Brush;
XamlLight.AddTargetBrush(Lights.RevealAmbientLight.GetIdStatic(), this);
XamlLight.AddTargetBrush(Lights.RevealBorderSpotLight.GetIdStatic(), this);
}
protected override void OnDisconnected(UIElement oldElement)
{
// 这一句是对应的，Add了之后就要Remove
XamlLight.RemoveTargetElement(GetId(), oldElement);
// 释放资源
CompositionLight.Dispose();
CompositionLight = null;
}
protected override void OnConnected(UIElement newElement)
{
(newElement as FrameworkElement).SizeChanged += XamlPointLight_SizeChanged;
// 创建灯光
var compositor = Window.Current.Compositor;
PointLight light = compositor.CreatePointLight();
// 设置灯光参数
light.Color = ((SolidColorBrush)Color).Color;
CompositionLight = light;
// 这一句很重要
XamlLight.AddTargetElement(GetId(), newElement);
}
// Handle attached property changed to automatically target and untarget UIElements and Brushes.
private static void OnTargetIdPropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
string oldId = e.OldValue as string;
string newId = e.NewValue as string;
string[] oldIds = null;
if (!string.IsNullOrEmpty(oldId))
{
oldIds = oldId.Split(',');
}
else
{
oldIds = new string[0];
}
string[] newIds = null;
if (!string.IsNullOrEmpty(newId))
{
newIds = newId.Split(',');
}
else
{
newIds = new string[0];
}
List <string> added = new List <string>();
List <string> removed = new List <string>();
foreach (var id in newIds)
{
if (!oldIds.Contains(id))
{
added.Add(id);
}
}
foreach (var id in oldIds)
{
if (!newIds.Contains(id))
{
removed.Add(id);
}
}
foreach (var id in added)
{
if (obj is UIElement)
{
XamlLight.AddTargetElement(GetIdStatic(id), obj as UIElement);
}
else if (obj is Brush)
{
XamlLight.AddTargetBrush(GetIdStatic(id), obj as Brush);
}
}
foreach (var id in removed)
{
if (obj is UIElement)
{
XamlLight.RemoveTargetElement(GetIdStatic(id), obj as UIElement);
}
else if (obj is Brush)
{
XamlLight.RemoveTargetBrush(GetIdStatic(id), obj as Brush);
}
}
}
protected override void OnDisconnected()
{
base.OnDisconnected();
XamlLight.RemoveTargetBrush(Lights.RevealAmbientLight.GetIdStatic(), this);
XamlLight.RemoveTargetBrush(Lights.RevealBorderSpotLight.GetIdStatic(), this);
}
