ISelectionService Interface
.NET Framework 3.0
Provides an interface for a designer to select components.
Namespace: System.ComponentModel.Design
Assembly: System (in system.dll)
Assembly: System (in system.dll)
The following example demonstrates use of the ISelectionService to handle the SelectionChanged and SelectionChanging events.
Imports System Imports System.Drawing Imports System.Collections Imports System.ComponentModel Imports System.ComponentModel.Design Imports System.Windows.Forms Imports Microsoft.VisualBasic ' 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 'New 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 'OnSelectionChanged 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 'OnSelectionChanging 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 'Dispose End Class 'SelectionComponent End Namespace 'ISelectionServiceExample
package ISelectionServiceExample;
import System.*;
import System.Drawing.*;
import System.Collections.*;
import System.ComponentModel.*;
import System.ComponentModel.Design.*;
import 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.
*/
public class SelectionComponent extends System.Windows.Forms.UserControl
{
private System.Windows.Forms.TextBox tbox1;
private ISelectionService selectionService;
public SelectionComponent()
{
// Initialize control
this.SuspendLayout();
this.set_Name("SelectionComponent");
this.set_Size(new System.Drawing.Size(608, 296));
this.tbox1 = new System.Windows.Forms.TextBox();
this.tbox1.set_Location(new System.Drawing.Point(24, 16));
this.tbox1.set_Name("listBox1");
this.tbox1.set_Multiline(true);
this.tbox1.set_Size(new System.Drawing.Size(560, 251));
this.tbox1.set_TabIndex(0);
this.get_Controls().Add(this.tbox1);
this.ResumeLayout();
} //SelectionComponent
/** @property
*/
public ISite get_Site()
{
return super.get_Site();
} //get_Site
/** @property
*/
public void set_Site(ISite value)
{
// 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.remove_SelectionChanged(
new EventHandler(OnSelectionChanged));
selectionService.remove_SelectionChanging(
new EventHandler(OnSelectionChanging));
}
// Establish the new site for the component.
super.set_Site(value);
if (super.get_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.get_Site().GetService(ISelectionService.class.ToType())));
// 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.add_SelectionChanging(
new EventHandler(OnSelectionChanging));
selectionService.add_SelectionChanged(
new EventHandler(OnSelectionChanged));
}
} //set_Site
private void OnSelectionChanged(Object sender, EventArgs args)
{
tbox1.AppendText("The selected component was changed. Selected"
+ " components:\r\n " + GetSelectedComponents() + "\r\n");
} //OnSelectionChanged
private void OnSelectionChanging(Object sender, EventArgs args)
{
tbox1.AppendText("The selected component is changing. Selected"
+ " components:\r\n " + GetSelectedComponents() + "\r\n");
} //OnSelectionChanging
private String GetSelectedComponents()
{
String selectedString = "";
Object components[] = new Object[((ICollection)(
selectionService.GetSelectedComponents())).get_Count()];
((ICollection)(selectionService.GetSelectedComponents())).
CopyTo(components, 0);
for (int i = 0; i < components.length; i++) {
if (i != 0) {
selectedString += "&& ";
}
if (((IComponent)(selectionService.get_PrimarySelection())).Equals(
(IComponent)(components.get_Item(i)))) {
selectedString += "PrimarySelection:";
}
selectedString += ((IComponent)(components.get_Item(i))).
get_Site().get_Name() + " ";
}
return selectedString;
} //GetSelectedComponents
// Clean up any resources being used.
protected void Dispose(boolean disposing)
{
// Detatch the event handlers for the selection service.
if (selectionService != null) {
selectionService.remove_SelectionChanging(
new EventHandler(this.OnSelectionChanging));
selectionService.remove_SelectionChanged(
new EventHandler(this.OnSelectionChanged));
}
super.Dispose(disposing);
} //Dispose
} //SelectionComponent
Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.Community Additions
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