ItemPolicy.GetSurrogateItems Method
Returns an optional set of surrogate items for this item.
Namespace: Microsoft.Windows.Design.Policies
Assembly: Microsoft.Windows.Design.Interaction (in Microsoft.Windows.Design.Interaction.dll)
Syntax
'Declaration
Public Overridable Function GetSurrogateItems ( _
item As ModelItem _
) As IEnumerable(Of ModelItem)
public virtual IEnumerable<ModelItem> GetSurrogateItems(
ModelItem item
)
public:
virtual IEnumerable<ModelItem^>^ GetSurrogateItems(
ModelItem^ item
)
abstract GetSurrogateItems :
item:ModelItem -> IEnumerable<ModelItem>
override GetSurrogateItems :
item:ModelItem -> IEnumerable<ModelItem>
public function GetSurrogateItems(
item : ModelItem
) : IEnumerable<ModelItem>
Parameters
- item
Type: Microsoft.Windows.Design.Model.ModelItem
The item to retrieve the surrogate for.
Return Value
Type: System.Collections.Generic.IEnumerable<ModelItem>
An enumeration of surrogate items to check. The default returns an empty enumeration.
Remarks
Surrogate items provide additional features for the specified item. Surrogate items are not part of the items that are exposed to consumers of the policy. Return surrogate items if you need a parent object to offer features for a child. To return a set of surrogate items, override the IsSurrogate property so that it returns true.
Note
Do not return nulla null reference (Nothing in Visual Basic) from your GetSurrogateItems implementation.
Examples
The following code example shows how to create a custom surrogate policy by implementing the IsSurrogate property and the GetSurrogateItems method. For a full code listing, see How to: Create a Surrogate Policy.
' The DockPanelPolicy class implements a surrogate policy that
' provides container semantics for a selected item. By using
' this policy, the DemoDockPanel container control offers
' additional tasks and adorners on its children.
Class DockPanelPolicy
Inherits PrimarySelectionPolicy
Public Overrides ReadOnly Property IsSurrogate() As Boolean
Get
Return True
End Get
End Property
Public Overrides Function GetSurrogateItems( _
ByVal item As Microsoft.Windows.Design.Model.ModelItem) _
As System.Collections.Generic.IEnumerable( _
Of Microsoft.Windows.Design.Model.ModelItem)
Dim parent As ModelItem = item.Parent
Dim e As New System.Collections.Generic.List(Of ModelItem)
If (parent IsNot Nothing) Then
e.Add(parent)
End If
Return e
End Function
End Class
// The DockPanelPolicy class implements a surrogate policy that
// provides container semantics for a selected item. By using
// this policy, the DemoDockPanel container control offers
// additional tasks and adorners on its children.
class DockPanelPolicy : PrimarySelectionPolicy
{
public override bool IsSurrogate
{
get
{
return true;
}
}
public override IEnumerable<ModelItem> GetSurrogateItems(ModelItem item)
{
ModelItem parent = item.Parent;
if (parent != null)
{
yield return parent;
}
}
}
.NET Framework Security
- Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.
See Also
Reference
Microsoft.Windows.Design.Policies Namespace