ISelectionService Interface
Provides an interface for a designer to select components.
For a list of all members of this type, see ISelectionService Members.
[Visual Basic] <ComVisible(True)> Public Interface ISelectionService [C#] [ComVisible(true)] public interface ISelectionService [C++] [ComVisible(true)] public __gc __interface ISelectionService [JScript] public ComVisible(true) interface ISelectionService
Remarks
When a component is selected, its viewable or editable properties are shown in the Properties window.
Example
[Visual Basic, C#, C++] The following example demonstrates use of the ISelectionService to handle the SelectionChanged and SelectionChanging events.
[Visual Basic] 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 Not (selectionService Is 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 Not (selectionService Is 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 Not (selectionService Is 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 [C#] 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 ); } } } [C++] #using <mscorlib.dll> #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 __gc class SelectionComponent : public System::Windows::Forms::UserControl { private: System::Windows::Forms::TextBox* tbox1; ISelectionService* selectionService; public: SelectionComponent() { // Initialize control this->SuspendLayout(); this->Name = S"SelectionComponent"; this->Size = System::Drawing::Size(608, 296); this->tbox1 = new System::Windows::Forms::TextBox(); this->tbox1->Location = System::Drawing::Point(24, 16); this->tbox1->Name = S"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* get_Site() { return UserControl::get_Site(); } __property void set_Site( ISite* value ) { // The ISelectionService is available in design mode // only, and only after the component is sited. if (selectionService != 0) { // 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(this, &SelectionComponent::OnSelectionChanged); selectionService->SelectionChanging -= new EventHandler(this, &SelectionComponent::OnSelectionChanging); } // Establish the new site for the component. UserControl::set_Site( value ); if( UserControl::Site == 0 ) 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(__typeof(ISelectionService))); // If an instance of the ISelectionService was obtained, // attach event handlers for the selection // changing and selection changed events. if (selectionService != 0) { // Add an event handler for the SelectionChanging // and SelectionChanged events. selectionService->SelectionChanging += new EventHandler(this, &SelectionComponent::OnSelectionChanging); selectionService->SelectionChanged += new EventHandler(this, &SelectionComponent::OnSelectionChanged); } } private: void OnSelectionChanged(Object* /*sender*/, EventArgs* /*args*/) { tbox1->AppendText(String::Format( S"The selected component was changed. Selected components:\r\n {0}\r\n", GetSelectedComponents() )); } void OnSelectionChanging(Object* /*sender*/, EventArgs* /*args*/) { tbox1->AppendText(String::Format( S"The selected component is changing. Selected components:\r\n {0}\r\n", GetSelectedComponents() )); } String* GetSelectedComponents() { String* selectedString = String::Empty; Object* components[] = new 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 = String::Concat( selectedString, S"&& " ); if( (dynamic_cast<IComponent*>(selectionService->PrimarySelection)) == (dynamic_cast<IComponent*>(components[i])) ) selectedString = String::Concat( selectedString, S"PrimarySelection:" ); selectedString = String::Concat( selectedString, (dynamic_cast<IComponent*>(components[i]))->Site->Name, S" " ); } return selectedString; } // Clean up any resources being used. protected: void Dispose( bool disposing ) { // Detach the event handlers for the selection service. if( selectionService != 0 ) { selectionService->SelectionChanging -= new EventHandler(this, &SelectionComponent::OnSelectionChanging); selectionService->SelectionChanged -= new EventHandler(this, &SelectionComponent::OnSelectionChanged); } UserControl::Dispose( disposing ); } }; }
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Requirements
Namespace: System.ComponentModel.Design
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family
Assembly: System (in System.dll)
See Also
ISelectionService Members | System.ComponentModel.Design Namespace