ISelectionService Interface
Definition
Important
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Provides an interface for a designer to select components.
public interface class ISelectionServicepublic interface ISelectionService[System.Runtime.InteropServices.ComVisible(true)]
public interface ISelectionServicetype ISelectionService = interface[<System.Runtime.InteropServices.ComVisible(true)>]
type ISelectionService = interfacePublic Interface ISelectionService- Attributes
Examples
The following example demonstrates use of the ISelectionService to handle the SelectionChanged and SelectionChanging events.
#using <System.Windows.Forms.dll>
#using <System.dll>
#using <System.Drawing.dll>
using namespace System;
using namespace System::Drawing;
using namespace System::Collections;
using namespace System::ComponentModel;
using namespace System::ComponentModel::Design;
using namespace System::Windows::Forms;
/* This sample demonstrates using the ISelectionService
interface to receive notification of selection change events.
The SelectionComponent control attempts to retrieve an instance
of the ISelectionService when it is sited. If it can, it attaches
event handlers for events provided by the service that display
a message when a component is selected or deselected.
To run this sample, add the SelectionComponent control to a Form and
then select or deselect components in design mode to see the behavior
of the component change event handlers. */
namespace ISelectionServiceExample
{
public ref class SelectionComponent: public System::Windows::Forms::UserControl
{
private:
System::Windows::Forms::TextBox^ tbox1;
ISelectionService^ selectionService;
public:
SelectionComponent()
{
// Initialize control
this->SuspendLayout();
this->Name = "SelectionComponent";
this->Size = System::Drawing::Size( 608, 296 );
this->tbox1 = gcnew System::Windows::Forms::TextBox;
this->tbox1->Location = System::Drawing::Point( 24, 16 );
this->tbox1->Name = "listBox1";
this->tbox1->Multiline = true;
this->tbox1->Size = System::Drawing::Size( 560, 251 );
this->tbox1->TabIndex = 0;
this->Controls->Add( this->tbox1 );
this->ResumeLayout();
}
property ISite^ Site
{
virtual ISite^ get() override
{
return __super::Site;
}
virtual void set( ISite^ value ) override
{
// The ISelectionService is available in design mode
// only, and only after the component is sited.
if ( selectionService != nullptr )
{
// Because the selection service has been
// previously obtained, the component may be in
// the process of being resited.
// Detatch the previous selection change event
// handlers in case the new selection
// service is a new service instance belonging to
// another design mode service host.
selectionService->SelectionChanged -= gcnew EventHandler( this, &SelectionComponent::OnSelectionChanged );
selectionService->SelectionChanging -= gcnew EventHandler( this, &SelectionComponent::OnSelectionChanging );
}
// Establish the new site for the component.
__super::Site = value;
if ( __super::Site == nullptr )
return;
// The selection service is not available outside of
// design mode. A call requesting the service
// using GetService while not in design mode will
// return null.
selectionService = dynamic_cast<ISelectionService^>(this->Site->GetService( ISelectionService::typeid ));
// If an instance of the ISelectionService was obtained,
// attach event handlers for the selection
// changing and selection changed events.
if ( selectionService != nullptr )
{
// Add an event handler for the SelectionChanging
// and SelectionChanged events.
selectionService->SelectionChanging += gcnew EventHandler( this, &SelectionComponent::OnSelectionChanging );
selectionService->SelectionChanged += gcnew EventHandler( this, &SelectionComponent::OnSelectionChanged );
}
}
}
private:
void OnSelectionChanged( Object^ /*sender*/, EventArgs^ /*args*/ )
{
tbox1->AppendText( String::Format( "The selected component was changed. Selected components:\r\n {0}\r\n", GetSelectedComponents() ) );
}
void OnSelectionChanging( Object^ /*sender*/, EventArgs^ /*args*/ )
{
tbox1->AppendText( String::Format( "The selected component is changing. Selected components:\r\n {0}\r\n", GetSelectedComponents() ) );
}
String^ GetSelectedComponents()
{
String^ selectedString = String::Empty;
array<Object^>^components = gcnew array<Object^>((dynamic_cast<ICollection^>(selectionService->GetSelectedComponents()))->Count);
(dynamic_cast<ICollection^>(selectionService->GetSelectedComponents()))->CopyTo( components, 0 );
for ( int i = 0; i < components->Length; i++ )
{
if ( i != 0 )
selectedString = selectedString + "&& ";
if ( (dynamic_cast<IComponent^>(selectionService->PrimarySelection)) == (dynamic_cast<IComponent^>(components[ i ])) )
selectedString = selectedString + "PrimarySelection:";
selectedString = selectedString + (dynamic_cast<IComponent^>(components[ i ]))->Site->Name + " ";
}
return selectedString;
}
// Clean up any resources being used.
public:
~SelectionComponent()
{
// Detach the event handlers for the selection service.
if ( selectionService != nullptr )
{
selectionService->SelectionChanging -= gcnew EventHandler( this, &SelectionComponent::OnSelectionChanging );
selectionService->SelectionChanged -= gcnew EventHandler( this, &SelectionComponent::OnSelectionChanged );
}
}
};
}
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Windows.Forms;
/* This sample demonstrates using the ISelectionService
interface to receive notification of selection change events.
The SelectionComponent control attempts to retrieve an instance
of the ISelectionService when it is sited. If it can, it attaches
event handlers for events provided by the service that display
a message when a component is selected or deselected.
To run this sample, add the SelectionComponent control to a Form and
then select or deselect components in design mode to see the behavior
of the component change event handlers. */
namespace ISelectionServiceExample
{
public class SelectionComponent : System.Windows.Forms.UserControl
{
private System.Windows.Forms.TextBox tbox1;
private ISelectionService selectionService;
public SelectionComponent()
{
// Initialize control
this.SuspendLayout();
this.Name = "SelectionComponent";
this.Size = new System.Drawing.Size(608, 296);
this.tbox1 = new System.Windows.Forms.TextBox();
this.tbox1.Location = new System.Drawing.Point(24, 16);
this.tbox1.Name = "listBox1";
this.tbox1.Multiline = true;
this.tbox1.Size = new System.Drawing.Size(560, 251);
this.tbox1.TabIndex = 0;
this.Controls.Add(this.tbox1);
this.ResumeLayout();
}
public override ISite Site
{
get
{
return base.Site;
}
set
{
// The ISelectionService is available in design mode
// only, and only after the component is sited.
if (selectionService != null)
{
// Because the selection service has been
// previously obtained, the component may be in
// the process of being resited.
// Detatch the previous selection change event
// handlers in case the new selection
// service is a new service instance belonging to
// another design mode service host.
selectionService.SelectionChanged -= new EventHandler(OnSelectionChanged);
selectionService.SelectionChanging -= new EventHandler(OnSelectionChanging);
}
// Establish the new site for the component.
base.Site = value;
if( base.Site == null )
return;
// The selection service is not available outside of
// design mode. A call requesting the service
// using GetService while not in design mode will
// return null.
selectionService = (ISelectionService)this.Site.GetService(typeof(ISelectionService));
// If an instance of the ISelectionService was obtained,
// attach event handlers for the selection
// changing and selection changed events.
if (selectionService != null)
{
// Add an event handler for the SelectionChanging
// and SelectionChanged events.
selectionService.SelectionChanging += new EventHandler(OnSelectionChanging);
selectionService.SelectionChanged += new EventHandler(OnSelectionChanged);
}
}
}
private void OnSelectionChanged(object sender, EventArgs args)
{
tbox1.AppendText("The selected component was changed. Selected components:\r\n " + GetSelectedComponents() + "\r\n");
}
private void OnSelectionChanging(object sender, EventArgs args)
{
tbox1.AppendText("The selected component is changing. Selected components:\r\n " + GetSelectedComponents() + "\r\n");
}
private string GetSelectedComponents()
{
string selectedString = String.Empty;
object[] components = new object[((ICollection)selectionService.GetSelectedComponents()).Count];
((ICollection)selectionService.GetSelectedComponents()).CopyTo(components, 0);
for(int i=0; i<components.Length; i++)
{
if( i != 0 )
selectedString += "&& ";
if( ((IComponent)selectionService.PrimarySelection) == ((IComponent)components[i]) )
selectedString += "PrimarySelection:";
selectedString += ((IComponent)components[i]).Site.Name+" ";
}
return selectedString;
}
// Clean up any resources being used.
protected override void Dispose( bool disposing )
{
// Detatch the event handlers for the selection service.
if( selectionService != null )
{
selectionService.SelectionChanging -= new EventHandler(this.OnSelectionChanging);
selectionService.SelectionChanged -= new EventHandler(this.OnSelectionChanged);
}
base.Dispose( disposing );
}
}
}
Imports System.Drawing
Imports System.Collections
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Windows.Forms
' This sample demonstrates using the ISelectionService
' interface to receive notification of selection change events.
' The SelectionComponent control attempts to retrieve an instance
' of the ISelectionService when it is sited. If it can, it attaches
' event handlers for events provided by the service that display
' a message when a component is selected or deselected.
' To run this sample, add the SelectionComponent control to a Form and
' then select or deselect components in design mode to see the behavior
' of the component change event handlers.
Namespace ISelectionServiceExample
Public Class SelectionComponent
Inherits System.Windows.Forms.UserControl
Private tbox1 As System.Windows.Forms.TextBox
Private selectionService As ISelectionService
Public Sub New()
' Initialize control
Me.SuspendLayout()
Me.Name = "SelectionComponent"
Me.Size = New System.Drawing.Size(608, 296)
Me.tbox1 = New System.Windows.Forms.TextBox()
Me.tbox1.Location = New System.Drawing.Point(24, 16)
Me.tbox1.Name = "listBox1"
Me.tbox1.Multiline = True
Me.tbox1.Size = New System.Drawing.Size(560, 251)
Me.tbox1.TabIndex = 0
Me.Controls.Add(Me.tbox1)
Me.ResumeLayout()
End Sub
Public Overrides Property Site() As ISite
Get
Return MyBase.Site
End Get
Set(ByVal Value As ISite)
' The ISelectionService is available in design mode
' only, and only after the component is sited.
If (selectionService IsNot Nothing) Then
' Because the selection service has been
' previously obtained, the component may be in
' the process of being resited.
' Detatch the previous selection change event
' handlers in case the new selection
' service is a new service instance belonging to
' another design mode service host.
RemoveHandler selectionService.SelectionChanged, AddressOf OnSelectionChanged
RemoveHandler selectionService.SelectionChanging, AddressOf OnSelectionChanging
End If
' Establish the new site for the component.
MyBase.Site = Value
If MyBase.Site Is Nothing Then
Return
End If
' The selection service is not available outside of
' design mode. A call requesting the service
' using GetService while not in design mode will
' return null.
selectionService = Me.Site.GetService(GetType(ISelectionService))
' If an instance of the ISelectionService was obtained,
' attach event handlers for the selection
' changing and selection changed events.
If (selectionService IsNot Nothing) Then
' Add an event handler for the SelectionChanging and SelectionChanged events.
AddHandler selectionService.SelectionChanging, AddressOf OnSelectionChanging
AddHandler selectionService.SelectionChanged, AddressOf OnSelectionChanged
End If
End Set
End Property
Private Sub OnSelectionChanged(ByVal sender As Object, ByVal args As EventArgs)
tbox1.AppendText("The selected component was changed. Selected components:" + Microsoft.VisualBasic.ControlChars.CrLf + " " + GetSelectedComponents() + Microsoft.VisualBasic.ControlChars.CrLf)
End Sub
Private Sub OnSelectionChanging(ByVal sender As Object, ByVal args As EventArgs)
tbox1.AppendText("The selected component is changing. Selected components:" + Microsoft.VisualBasic.ControlChars.CrLf + " " + GetSelectedComponents() + Microsoft.VisualBasic.ControlChars.CrLf)
End Sub
Private Function GetSelectedComponents() As String
Dim selectedString As String = String.Empty
Dim components(CType(selectionService.GetSelectedComponents(), ICollection).Count - 1) As Object
CType(selectionService.GetSelectedComponents(), ICollection).CopyTo(components, 0)
Dim i As Integer
For i = 0 To components.Length - 1
If i <> 0 Then
selectedString += "&& "
End If
If CType(selectionService.PrimarySelection, IComponent) Is CType(components(i), IComponent) Then
selectedString += "PrimarySelection:"
End If
selectedString += CType(components(i), IComponent).Site.Name + " "
Next i
Return selectedString
End Function 'GetSelectedComponents
' Clean up any resources being used.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
' Detatch the event handlers for the selection service.
If (selectionService IsNot Nothing) Then
RemoveHandler selectionService.SelectionChanging, AddressOf OnSelectionChanging
RemoveHandler selectionService.SelectionChanged, AddressOf OnSelectionChanged
End If
MyBase.Dispose(disposing)
End Sub
End Class
End Namespace 'ISelectionServiceExample
Remarks
When a component is selected, its viewable or editable properties are shown in the Properties window.
Properties
| PrimarySelection |
Gets the object that is currently the primary selected object. |
| SelectionCount |
Gets the count of selected objects. |
Methods
| GetComponentSelected(Object) |
Gets a value indicating whether the specified component is currently selected. |
| GetSelectedComponents() |
Gets a collection of components that are currently selected. |
| SetSelectedComponents(ICollection, SelectionTypes) |
Selects the components from within the specified collection of components that match the specified selection type. |
| SetSelectedComponents(ICollection) |
Selects the specified collection of components. |
Events
| SelectionChanged |
Occurs when the current selection changes. |
| SelectionChanging |
Occurs when the current selection is about to change. |
Applies to
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