ITypeDescriptorFilterService Interface
Provides an interface to modify the set of member descriptors for a component in design mode.
For a list of all members of this type, see ITypeDescriptorFilterService Members.
[Visual Basic] Public Interface ITypeDescriptorFilterService [C#] public interface ITypeDescriptorFilterService [C++] public __gc __interface ITypeDescriptorFilterService [JScript] public interface ITypeDescriptorFilterService
Classes that Implement ITypeDescriptorFilterService
| Class | Description |
|---|---|
| ComponentDocumentDesigner | Base designer class for extending the design mode behavior of a root design document that supports nested components. |
Remarks
ITypeDescriptorFilterService provides an interface that a component can implement to modify the set of descriptors that a component provides through a TypeDescriptor. TypeDescriptor will query a component's site for the ITypeDescriptorFilterService service before providing descriptors representing its properties, attributes, and events.
Notes to Implementers: To filter the member descriptors exposed by a TypeDescriptor, implement this interface on a component and override the FilterAttributes, FilterEvents or FilterProperties methods of this class to filter the attributes, events, or properties, respectively.
Example
[Visual Basic, C#, C++] The following example demonstrates a designer that uses the ITypeDescriptorFilterService to filter the attributes collection of any new or existing System.Windows.Forms.Button to add a designer attribute for a new designer before loading or reloading the designer for the button.
[Visual Basic, C#, C++] To use the example, compile the code as a class library and load the components from the class library into the toolbox in a Windows Forms project using the Customize Toolbox command. Add some buttons to your form. Add a ButtonDesignerFilterComponent to your form, and it will appear in the component tray. The ButtonDesignerFilterComponent will add a ButtonDesignerFilterService ITypeDescriptorFilterService as a design mode service provider. Existing or new System.Windows.Forms.Button objects on the form will begin color cycling after the ButtonDesignerFilterService replaces the designer for each existing, and any new buttons, with a ColorCycleButtonDesigner. The buttons will color cycle when you mouse over them, and alternately continue cycling or reset the background and foreground colors on MouseLeave events. New System.Windows.Forms.Button objects will be given the ColorCycleButtonDesigner through the FilterAttributes method of the ButtonDesignerFilterService ITypeDescriptorFilterService that has been loaded, until the ButtonDesignerFilterComponent is disposed and replaces the original ITypeDescriptorFilterService. The ColorCycleButton class in this example is a System.Windows.Forms.Button associated with a ColorCycleButtonDesigner.
[Visual Basic] Imports System Imports System.Collections Imports System.ComponentModel Imports System.ComponentModel.Design Imports System.ComponentModel.Design.Serialization Imports System.Drawing Imports System.Reflection Imports System.Timers Imports System.Windows.Forms Imports System.Windows.Forms.Design Namespace ITypeDescriptorFilterSample ' Component to host the ButtonDesignerFilterComponentDesigner that loads the ' ButtonDesignerFilterService ITypeDescriptorFilterService. <Designer(GetType(ButtonDesignerFilterComponentDesigner))> _ Public Class ButtonDesignerFilterComponent Inherits System.ComponentModel.Component Public Sub New(ByVal container As System.ComponentModel.IContainer) container.Add(Me) End Sub 'New Public Sub New() End Sub 'New End Class 'ButtonDesignerFilterComponent ' Provides a designer that can add a ColorCycleButtonDesigner to each ' button in a design time project using the ButtonDesignerFilterService ' ITypeDescriptorFilterService. Public Class ButtonDesignerFilterComponentDesigner Inherits System.ComponentModel.Design.ComponentDesigner ' Indicates whether the service has been loaded. Private serviceloaded As Boolean = False ' Stores any old ITypeDescriptorFilterService to restore later. Private oldservice As ITypeDescriptorFilterService = Nothing Public Sub New() End Sub ' Loads the new ITypeDescriptorFilterService and reloads the ' designers for each Button. Public Overrides Sub Initialize(ByVal component As System.ComponentModel.IComponent) MyBase.Initialize(component) ' Loads the custom service if it has not been loaded already. LoadService() ' Build list of buttons from Container.Components. Dim buttons As New ArrayList() Dim c As IComponent For Each c In Me.Component.Site.Container.Components If TypeOf c Is System.Windows.Forms.Button Then buttons.Add(CType(c, System.Windows.Forms.Button)) End If Next c If buttons.Count > 0 Then ' Tests each Button for an existing ' ColorCycleButtonDesigner; ' if it has no designer of type ' ColorCycleButtonDesigner, adds a designer. Dim b As System.Windows.Forms.Button For Each b In buttons Dim loaddesigner As Boolean = True ' Gets the attributes for each button. Dim ac As AttributeCollection = TypeDescriptor.GetAttributes(b) Dim i As Integer For i = 0 To ac.Count - 1 ' If designer attribute is not for a ' ColorCycleButtonDesigner, adds a new ' ColorCycleButtonDesigner. If TypeOf ac(i) Is DesignerAttribute Then Dim da As DesignerAttribute = CType(ac(i), DesignerAttribute) If da.DesignerTypeName.Substring((da.DesignerTypeName.LastIndexOf(".") + 1)) = "ColorCycleButtonDesigner" Then loaddesigner = False End If End If Next i If loaddesigner Then ' Saves the button location so that it ' can be repositioned. Dim p As Point = b.Location ' Gets an IMenuCommandService to cut and ' paste control in order to register with ' selection and movement interface after ' designer is changed without reloading. Dim imcs As IMenuCommandService = CType(Me.GetService(GetType(IMenuCommandService)), IMenuCommandService) If imcs Is Nothing Then Throw New Exception("Could not obtain IMenuCommandService interface.") End If ' Gets an ISelectionService to select the ' button so that it can be cut and pasted. Dim iss As ISelectionService = CType(Me.GetService(GetType(ISelectionService)), ISelectionService) If iss Is Nothing Then Throw New Exception("Could not obtain ISelectionService interface.") End If iss.SetSelectedComponents(New IComponent() {b}, SelectionTypes.Normal) ' Invoke Cut and Paste. imcs.GlobalInvoke(StandardCommands.Cut) imcs.GlobalInvoke(StandardCommands.Paste) ' Regains reference to button from ' selection service. Dim b2 As System.Windows.Forms.Button = CType(iss.PrimarySelection, System.Windows.Forms.Button) iss.SetSelectedComponents(Nothing) ' Refreshes TypeDescriptor properties of ' button to load new attributes from ' ButtonDesignerFilterService. TypeDescriptor.Refresh(b2) b2.Location = p b2.Focus() End If Next b End If End Sub ' Loads a ButtonDesignerFilterService ITypeDescriptorFilterService ' to add ColorCycleButtonDesigner designers to each button. Private Sub LoadService() ' If no custom ITypeDescriptorFilterService is loaded, ' loads it now. If Not serviceloaded Then ' Stores the current ITypeDescriptorFilterService ' to restore later. Dim tdfs As ITypeDescriptorFilterService = CType(Me.Component.Site.GetService(GetType(ITypeDescriptorFilterService)), ITypeDescriptorFilterService) If Not (tdfs Is Nothing) Then oldservice = tdfs End If ' Retrieves an IDesignerHost interface to use to ' remove and add services. Dim dh As IDesignerHost = CType(Me.Component.Site.GetService(GetType(IDesignerHost)), IDesignerHost) If dh Is Nothing Then Throw New Exception("Could not obtain IDesignerHost interface.") End If ' Removes the standard ITypeDescriptorFilterService. dh.RemoveService(GetType(ITypeDescriptorFilterService)) ' Adds the new custom ITypeDescriptorFilterService. dh.AddService(GetType(ITypeDescriptorFilterService), New ButtonDesignerFilterService()) serviceloaded = True End If End Sub ' Removes the custom service and reloads any stored, ' preexisting service. Private Sub RemoveService() Dim dh As IDesignerHost = CType(Me.GetService(GetType(IDesignerHost)), IDesignerHost) If dh Is Nothing Then Throw New Exception("Could not obtain IDesignerHost interface.") End If dh.RemoveService(GetType(ITypeDescriptorFilterService)) If Not (oldservice Is Nothing) Then dh.AddService(GetType(ITypeDescriptorFilterService), oldservice) End If serviceloaded = False End Sub Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean) If serviceloaded Then RemoveService() End If End Sub End Class ' Provides a TypeDescriptorFilterService to add the ' ColorCycleButtonDesigner using a DesignerAttribute. Public Class ButtonDesignerFilterService Implements System.ComponentModel.Design.ITypeDescriptorFilterService Public oldService As ITypeDescriptorFilterService = Nothing Public Sub New() End Sub Public Sub New(ByVal oldService_ As ITypeDescriptorFilterService) ' Stores any previous ITypeDescriptorFilterService to implement service chaining. Me.oldService = oldService_ End Sub Public Function FilterAttributes(ByVal component As System.ComponentModel.IComponent, ByVal attributes As System.Collections.IDictionary) As Boolean Implements ITypeDescriptorFilterService.FilterAttributes If Not (oldService Is Nothing) Then oldService.FilterAttributes(component, attributes) End If ' Creates a designer attribute to compare its TypeID with the TypeID of existing attributes of the component. Dim da As New DesignerAttribute(GetType(ColorCycleButtonDesigner)) ' Adds the designer attribute if the attribute collection does not contain a DesignerAttribute of the same TypeID. If TypeOf component Is System.Windows.Forms.Button And attributes.Contains(da.TypeId) Then attributes(da.TypeId) = da End If Return True End Function Public Function FilterEvents(ByVal component As System.ComponentModel.IComponent, ByVal events As System.Collections.IDictionary) As Boolean Implements ITypeDescriptorFilterService.FilterEvents If Not (oldService Is Nothing) Then oldService.FilterEvents(component, events) End If Return True End Function Public Function FilterProperties(ByVal component As System.ComponentModel.IComponent, ByVal properties As System.Collections.IDictionary) As Boolean Implements ITypeDescriptorFilterService.FilterProperties If Not (oldService Is Nothing) Then oldService.FilterProperties(component, properties) End If Return True End Function End Class ' Designer for a Button control which cycles the background color. Public Class ColorCycleButtonDesigner Inherits System.Windows.Forms.Design.ControlDesigner Private timer1 As System.Windows.Forms.Timer Private initial_bcolor, initial_fcolor As Color Private r, g, b As Integer Private ru, gu, bu, continue_ As Boolean Public Sub New() timer1 = New System.Windows.Forms.Timer() timer1.Interval = 50 AddHandler timer1.Tick, AddressOf Me.Elapsed ru = True gu = False bu = True continue_ = False timer1.Start() End Sub Private Sub Elapsed(ByVal sender As Object, ByVal e As EventArgs) Me.Control.BackColor = Color.FromArgb(r Mod 255, g Mod 255, b Mod 255) Me.Control.Refresh() ' Updates color. If ru Then r += 10 Else If r > 10 Then r -= 10 End If End If If gu Then g += 10 Else If g > 10 Then g -= 10 End If End If If bu Then b += 10 Else If b > 10 Then b -= 10 End If End If ' Randomly switches direction of color component values. Dim rand As New Random() Dim i As Integer For i = 0 To 3 Select Case rand.Next(0, 2) Case 0 If ru Then ru = False Else ru = True End If Case 1 If gu Then gu = False Else gu = True End If Case 2 If bu Then bu = False Else bu = True End If End Select Next i Me.Control.ForeColor = Color.FromArgb((Me.Control.BackColor.R + 128) Mod 255, (Me.Control.BackColor.G + 128) Mod 255, (Me.Control.BackColor.B + 128) Mod 255) End Sub Protected Overrides Sub OnMouseEnter() If Not timer1.Enabled Then initial_bcolor = Me.Control.BackColor initial_fcolor = Me.Control.ForeColor r = initial_bcolor.R g = initial_bcolor.G b = initial_bcolor.B timer1.Start() End If End Sub Protected Overrides Sub OnMouseLeave() If Not continue_ Then continue_ = True timer1.Stop() Else continue_ = False End If Me.Control.BackColor = initial_bcolor Me.Control.ForeColor = initial_fcolor End Sub Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean) timer1.Stop() Me.Control.BackColor = initial_bcolor Me.Control.ForeColor = initial_fcolor MyBase.Dispose(disposing) End Sub End Class ' System.Windows.Forms.Button associated with the ColorCycleButtonDesigner. <Designer(GetType(ColorCycleButtonDesigner))> _ Public Class ColorCycleButton Inherits System.Windows.Forms.Button Public Sub New() End Sub End Class End Namespace [C#] using System; using System.Collections; using System.ComponentModel; using System.ComponentModel.Design; using System.ComponentModel.Design.Serialization; using System.Drawing; using System.Reflection; using System.Timers; using System.Windows.Forms; using System.Windows.Forms.Design; namespace ITypeDescriptorFilterSample { // Component to host the ButtonDesignerFilterComponentDesigner that loads the // ButtonDesignerFilterService ITypeDescriptorFilterService. [Designer(typeof(ButtonDesignerFilterComponentDesigner))] public class ButtonDesignerFilterComponent : System.ComponentModel.Component { public ButtonDesignerFilterComponent(System.ComponentModel.IContainer container) { container.Add(this); } public ButtonDesignerFilterComponent() {} } // Provides a designer that can add a ColorCycleButtonDesigner to each // button in a design time project using the ButtonDesignerFilterService // ITypeDescriptorFilterService. public class ButtonDesignerFilterComponentDesigner : System.ComponentModel.Design.ComponentDesigner { // Indicates whether the service has been loaded. private bool serviceloaded = false; // Stores any old ITypeDescriptorFilterService to restore later. private ITypeDescriptorFilterService oldservice = null; public ButtonDesignerFilterComponentDesigner() {} // Loads the new ITypeDescriptorFilterService and reloads the // designers for each button. public override void Initialize(System.ComponentModel.IComponent component) { base.Initialize(component); // Loads the custom service if it has not been loaded already LoadService(); // Build list of buttons from Container.Components. ArrayList buttons = new ArrayList(); foreach(IComponent c in this.Component.Site.Container.Components) if(c.GetType() == typeof(System.Windows.Forms.Button)) buttons.Add((System.Windows.Forms.Button)c); if(buttons.Count > 0) { // Tests each Button for an existing // ColorCycleButtonDesigner; // if it has no designer of type // ColorCycleButtonDesigner, adds a designer. foreach(System.Windows.Forms.Button b in buttons) { bool loaddesigner = true; // Gets the attributes for each button. AttributeCollection ac = TypeDescriptor.GetAttributes(b); for(int i=0; i<ac.Count; i++) { // If designer attribute is not for a // ColorCycleButtonDesigner, adds a new // ColorCycleButtonDesigner. if( ac[i] is DesignerAttribute ) { DesignerAttribute da = (DesignerAttribute)ac[i]; if( da.DesignerTypeName.Substring(da.DesignerTypeName.LastIndexOf(".")+1) == "ColorCycleButtonDesigner" ) loaddesigner = false; } } if(loaddesigner) { // Saves the button location so that it // can be repositioned. Point p = b.Location; // Gets an IMenuCommandService to cut and // paste control in order to register with // selection and movement interface after // designer is changed without reloading. IMenuCommandService imcs = (IMenuCommandService)this.GetService(typeof(IMenuCommandService)); if( imcs == null ) throw new Exception("Could not obtain IMenuCommandService interface."); // Gets an ISelectionService to select the // button so that it can be cut and pasted. ISelectionService iss = (ISelectionService)this.GetService(typeof(ISelectionService)); if( iss == null) throw new Exception("Could not obtain ISelectionService interface."); iss.SetSelectedComponents(new IComponent[] { b }, SelectionTypes.Normal); // Invoke Cut and Paste. imcs.GlobalInvoke(StandardCommands.Cut); imcs.GlobalInvoke(StandardCommands.Paste); // Regains reference to button from // selection service. System.Windows.Forms.Button b2 = (System.Windows.Forms.Button)iss.PrimarySelection; iss.SetSelectedComponents(null); // Refreshes TypeDescriptor properties of // button to load new attributes from // ButtonDesignerFilterService. TypeDescriptor.Refresh(b2); b2.Location = p; b2.Focus(); } } } } // Loads a ButtonDesignerFilterService ITypeDescriptorFilterService // to add ColorCycleButtonDesigner designers to each button. private void LoadService() { // If no custom ITypeDescriptorFilterService is loaded, // loads it now. if(!serviceloaded) { // Stores the current ITypeDescriptorFilterService // to restore later. ITypeDescriptorFilterService tdfs = (ITypeDescriptorFilterService)this.Component.Site.GetService(typeof(ITypeDescriptorFilterService)); if( tdfs != null ) oldservice = tdfs; // Retrieves an IDesignerHost interface to use to // remove and add services. IDesignerHost dh = (IDesignerHost)this.Component.Site.GetService(typeof(IDesignerHost)); if( dh == null ) throw new Exception("Could not obtain IDesignerHost interface."); // Removes standard ITypeDescriptorFilterService. dh.RemoveService(typeof(ITypeDescriptorFilterService)); // Adds new custom ITypeDescriptorFilterService. dh.AddService(typeof(ITypeDescriptorFilterService), new ButtonDesignerFilterService()); serviceloaded = true; } } // Removes the custom service and reloads any stored, // preexisting service. private void RemoveService() { IDesignerHost dh = (IDesignerHost)this.GetService(typeof(IDesignerHost)); if( dh == null ) throw new Exception("Could not obtain IDesignerHost interface."); dh.RemoveService(typeof(ITypeDescriptorFilterService)); if( oldservice != null ) dh.AddService(typeof(ITypeDescriptorFilterService), oldservice); serviceloaded = false; } protected override void Dispose(bool disposing) { if(serviceloaded) RemoveService(); } } // Provides a TypeDescriptorFilterService to add the // ColorCycleButtonDesigner using a DesignerAttribute. public class ButtonDesignerFilterService : System.ComponentModel.Design.ITypeDescriptorFilterService { public ITypeDescriptorFilterService oldService = null; public ButtonDesignerFilterService() {} public ButtonDesignerFilterService(ITypeDescriptorFilterService oldService_) { // Stores any previous ITypeDescriptorFilterService to implement service chaining. this.oldService = oldService_; } public bool FilterAttributes(System.ComponentModel.IComponent component, System.Collections.IDictionary attributes) { if(oldService != null) oldService.FilterAttributes(component, attributes); // Creates a designer attribute to compare its TypeID with the TypeID of existing attributes of the component. DesignerAttribute da = new DesignerAttribute(typeof(ColorCycleButtonDesigner)); // Adds the designer attribute if the attribute collection does not contain a DesignerAttribute of the same TypeID. if(component is System.Windows.Forms.Button && attributes.Contains(da.TypeId)) attributes[da.TypeId]=da; return true; } public bool FilterEvents(System.ComponentModel.IComponent component, System.Collections.IDictionary events) { if(oldService != null) oldService.FilterEvents(component, events); return true; } public bool FilterProperties(System.ComponentModel.IComponent component, System.Collections.IDictionary properties) { if(oldService != null) oldService.FilterProperties(component, properties); return true; } } // Designer for a Button control which cycles the background color. public class ColorCycleButtonDesigner : System.Windows.Forms.Design.ControlDesigner { private System.Windows.Forms.Timer timer1; private Color initial_bcolor, initial_fcolor; private int r, g, b; private bool ru, gu, bu, continue_; public ColorCycleButtonDesigner() { timer1 = new System.Windows.Forms.Timer(); timer1.Interval = 50; timer1.Tick += new EventHandler(this.Elapsed); ru = true; gu = false; bu = true; continue_ = false; timer1.Start(); } private void Elapsed(object sender, EventArgs e) { this.Control.BackColor = Color.FromArgb(r%255, g%255, b%255); this.Control.Refresh(); // Updates color. if(ru) r+=10; else if(r>10) r-=10; if(gu) g+=10; else if(g>10) g-=10; if(bu) b+=10; else if(b>10) b-=10; // Randomly switches direction of color component values. Random rand = new Random(); for(int i=0; i<4; i++) switch(rand.Next(0, 2)) { case 0: if(ru) ru=false; else ru=true; break; case 1: if(gu) gu=false; else gu=true; break; case 2: if(bu) bu=false; else bu=true; break; } this.Control.ForeColor = Color.FromArgb((this.Control.BackColor.R+128)%255, (this.Control.BackColor.G+128)%255, (this.Control.BackColor.B+128)%255); } protected override void OnMouseEnter() { if(!timer1.Enabled) { initial_bcolor = this.Control.BackColor; initial_fcolor = this.Control.ForeColor; r = initial_bcolor.R; g = initial_bcolor.G; b = initial_bcolor.B; timer1.Start(); } } protected override void OnMouseLeave() { if(!continue_) { continue_ = true; timer1.Stop(); } else continue_ = false; this.Control.BackColor = initial_bcolor; this.Control.ForeColor = initial_fcolor; } protected override void Dispose(bool disposing) { timer1.Stop(); this.Control.BackColor = initial_bcolor; this.Control.ForeColor = initial_fcolor; base.Dispose(disposing); } } // System.Windows.Forms.Button associated with the ColorCycleButtonDesigner. [Designer(typeof(ColorCycleButtonDesigner))] public class ColorCycleButton : System.Windows.Forms.Button { public ColorCycleButton() {} } } [C++] #using <mscorlib.dll> #using <System.Windows.Forms.dll> #using <System.Drawing.dll> #using <System.Design.dll> #using <System.dll> using namespace System; using namespace System::Collections; using namespace System::ComponentModel; using namespace System::ComponentModel::Design; using namespace System::ComponentModel::Design::Serialization; using namespace System::Drawing; using namespace System::Reflection; using namespace System::Timers; using namespace System::Windows::Forms; using namespace System::Windows::Forms::Design; namespace ITypeDescriptorFilterSample { // Designer for a Button control which cycles the background color. public __gc class ColorCycleButtonDesigner : public System::Windows::Forms::Design::ControlDesigner { private: System::Windows::Forms::Timer* timer1; Color initial_bcolor, initial_fcolor; int r, g, b; bool ru, gu, bu, continue_; public: ColorCycleButtonDesigner() { timer1 = new System::Windows::Forms::Timer(); timer1->Interval = 50; timer1->Tick += new EventHandler(this, &ColorCycleButtonDesigner::Elapsed); ru = true; gu = false; bu = true; continue_ = false; timer1->Start(); } private: void Elapsed(Object* /*sender*/, EventArgs* /*e*/) { this->Control->BackColor = Color::FromArgb(r%255, g%255, b%255); this->Control->Refresh(); // Updates color. if(ru) r+=10; else if(r>10) r-=10; if(gu) g+=10; else if(g>10) g-=10; if(bu) b+=10; else if(b>10) b-=10; // Randomly switches direction of color component values. Random* rand = new Random(); for(int i=0; i<4; i++) switch(rand->Next(0, 2)) { case 0: if(ru) ru=false; else ru=true; break; case 1: if(gu) gu=false; else gu=true; break; case 2: if(bu) bu=false; else bu=true; break; } this->Control->ForeColor = Color::FromArgb((this->Control->BackColor.R+128)%255, (this->Control->BackColor.G+128)%255, (this->Control->BackColor.B+128)%255); } protected: void OnMouseEnter() { if(!timer1->Enabled) { initial_bcolor = this->Control->BackColor; initial_fcolor = this->Control->ForeColor; r = initial_bcolor.R; g = initial_bcolor.G; b = initial_bcolor.B; timer1->Start(); } } void OnMouseLeave() { if(!continue_) { continue_ = true; timer1->Stop(); } else continue_ = false; this->Control->BackColor = initial_bcolor; this->Control->ForeColor = initial_fcolor; } void Dispose(bool disposing) { timer1->Stop(); this->Control->BackColor = initial_bcolor; this->Control->ForeColor = initial_fcolor; ControlDesigner::Dispose(disposing); } }; // Provides a TypeDescriptorFilterService to add the // ColorCycleButtonDesigner using a DesignerAttribute. public __gc class ButtonDesignerFilterService : public System::ComponentModel::Design::ITypeDescriptorFilterService { public: ITypeDescriptorFilterService* oldService; ButtonDesignerFilterService() {} ButtonDesignerFilterService(ITypeDescriptorFilterService* oldService_) { // Stores any previous ITypeDescriptorFilterService to implement service chaining. this->oldService = oldService_; } bool FilterAttributes(System::ComponentModel::IComponent* component, System::Collections::IDictionary* attributes) { if(oldService != 0) oldService->FilterAttributes(component, attributes); // Creates a designer attribute to compare its TypeID with the TypeID of existing attributes of the component. DesignerAttribute* da = new DesignerAttribute(__typeof(ColorCycleButtonDesigner)); // Adds the designer attribute if the attribute collection does not contain a DesignerAttribute of the same TypeID. if(dynamic_cast<System::Windows::Forms::Button*>(component) && attributes->Contains(da->TypeId)) attributes->Item[da->TypeId]=da; return true; } bool FilterEvents(System::ComponentModel::IComponent* component, System::Collections::IDictionary* events) { if(oldService != 0) oldService->FilterEvents(component, events); return true; } bool FilterProperties(System::ComponentModel::IComponent* component, System::Collections::IDictionary* properties) { if(oldService != 0) oldService->FilterProperties(component, properties); return true; } }; // System.Windows.Forms.Button associated with the ColorCycleButtonDesigner. [Designer(__typeof(ColorCycleButtonDesigner))] public __gc class ColorCycleButton : public System::Windows::Forms::Button { public: ColorCycleButton() {} }; // Provides a designer that can add a ColorCycleButtonDesigner to each // button in a design time project using the ButtonDesignerFilterService // ITypeDescriptorFilterService. public __gc class ButtonDesignerFilterComponentDesigner : public System::ComponentModel::Design::ComponentDesigner { // Indicates whether the service has been loaded. private: bool serviceloaded; // Stores any old ITypeDescriptorFilterService to restore later. ITypeDescriptorFilterService* oldservice; public: ButtonDesignerFilterComponentDesigner() { serviceloaded = false; } // Loads the new ITypeDescriptorFilterService and reloads the // designers for each button. void Initialize(System::ComponentModel::IComponent* component) { ComponentDesigner::Initialize(component); // Loads the custom service if it has not been loaded already LoadService(); // Build list of buttons from Container.Components. ArrayList* buttons = new ArrayList(); IEnumerator* myEnum = this->Component->Site->Container->Components->GetEnumerator(); while (myEnum->MoveNext()) { IComponent* c = __try_cast<IComponent*>(myEnum->Current); if(c->GetType() == __typeof(System::Windows::Forms::Button)) buttons->Add(dynamic_cast<System::Windows::Forms::Button*>(c)); } if(buttons->Count > 0) { // Tests each Button for an existing // ColorCycleButtonDesigner; // if it has no designer of type // ColorCycleButtonDesigner, adds a designer. IEnumerator* myEnum1 = buttons->GetEnumerator(); while (myEnum1->MoveNext()) { Button* b = __try_cast<Button*>(myEnum1->Current); bool loaddesigner = true; // Gets the attributes for each button. AttributeCollection* ac = TypeDescriptor::GetAttributes(b); for(int i=0; i<ac->Count; i++) { // If designer attribute is not for a // ColorCycleButtonDesigner, adds a new // ColorCycleButtonDesigner. if(dynamic_cast<DesignerAttribute*>( ac->Item[i]) ) { DesignerAttribute* da = dynamic_cast<DesignerAttribute*>(ac->Item[i]); if( da->DesignerTypeName->Substring(da->DesignerTypeName->LastIndexOf(S".")+1)->Equals(S"ColorCycleButtonDesigner") ) loaddesigner = false; } } if(loaddesigner) { // Saves the button location so that it // can be repositioned. Point p = b->Location; // Gets an IMenuCommandService to cut and // paste control in order to register with // selection and movement interface after // designer is changed without reloading. IMenuCommandService* imcs = dynamic_cast<IMenuCommandService*>(this->GetService(__typeof(IMenuCommandService))); if( imcs == 0 ) throw new Exception(S"Could not obtain IMenuCommandService interface."); // Gets an ISelectionService to select the // button so that it can be cut and pasted. ISelectionService* iss = dynamic_cast<ISelectionService*>(this->GetService(__typeof(ISelectionService))); if( iss == 0) throw new Exception(S"Could not obtain ISelectionService interface."); IComponent* temp0 [] = {b}; iss->SetSelectedComponents(dynamic_cast<ICollection __gc *>(temp0), SelectionTypes::Normal); // Invoke Cut and Paste. imcs->GlobalInvoke(StandardCommands::Cut); imcs->GlobalInvoke(StandardCommands::Paste); // Regains reference to button from // selection service. System::Windows::Forms::Button* b2 = dynamic_cast<System::Windows::Forms::Button*>(iss->PrimarySelection); iss->SetSelectedComponents(0); // Refreshes TypeDescriptor properties of // button to load new attributes from // ButtonDesignerFilterService. TypeDescriptor::Refresh(b2); b2->Location = p; b2->Focus(); } } } } // Loads a ButtonDesignerFilterService ITypeDescriptorFilterService // to add ColorCycleButtonDesigner designers to each button. private: void LoadService() { // If no custom ITypeDescriptorFilterService is loaded, // loads it now. if(!serviceloaded) { // Stores the current ITypeDescriptorFilterService // to restore later. ITypeDescriptorFilterService* tdfs = dynamic_cast<ITypeDescriptorFilterService*>(this->Component->Site->GetService(__typeof(ITypeDescriptorFilterService))); if( tdfs != 0 ) oldservice = tdfs; // Retrieves an IDesignerHost interface to use to // remove and add services. IDesignerHost* dh = dynamic_cast<IDesignerHost*>(this->Component->Site->GetService(__typeof(IDesignerHost))); if( dh == 0 ) throw new Exception(S"Could not obtain IDesignerHost interface."); // Removes standard ITypeDescriptorFilterService. dh->RemoveService(__typeof(ITypeDescriptorFilterService)); // Adds new custom ITypeDescriptorFilterService. dh->AddService(__typeof(ITypeDescriptorFilterService), new ButtonDesignerFilterService()); serviceloaded = true; } } // Removes the custom service and reloads any stored, // preexisting service. void RemoveService() { IDesignerHost* dh = dynamic_cast<IDesignerHost*>(this->GetService(__typeof(IDesignerHost))); if( dh == 0 ) throw new Exception(S"Could not obtain IDesignerHost interface."); dh->RemoveService(__typeof(ITypeDescriptorFilterService)); if( oldservice != 0 ) dh->AddService(__typeof(ITypeDescriptorFilterService), oldservice); serviceloaded = false; } protected: void Dispose(bool /*disposing*/) { if(serviceloaded) RemoveService(); } }; // Component to host the ButtonDesignerFilterComponentDesigner that loads the // ButtonDesignerFilterService ITypeDescriptorFilterService. [Designer(__typeof(ButtonDesignerFilterComponentDesigner))] public __gc class ButtonDesignerFilterComponent : public System::ComponentModel::Component { public: ButtonDesignerFilterComponent(System::ComponentModel::IContainer* container) { container->Add(this); } ButtonDesignerFilterComponent() {} }; }
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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
ITypeDescriptorFilterService Members | System.ComponentModel.Design Namespace