ITypeDescriptorFilterService Schnittstelle
Definition
Wichtig
Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.
Stellt eine Schnittstelle bereit, mit der der Satz der Memberdeskriptoren für eine Komponente im Entwurfsmodus bearbeitet werden kann.
public interface class ITypeDescriptorFilterServicepublic interface ITypeDescriptorFilterServicetype ITypeDescriptorFilterService = interfacePublic Interface ITypeDescriptorFilterService- Abgeleitet
Beispiele
Im folgenden Codebeispiel wird ein Designer veranschaulicht, der die Attributesammlung eines neuen oder vorhandenen Button Objekts zum Hinzufügen eines Designerattributes für einen neuen Designer verwendetITypeDescriptorFilterService, bevor der Designer für die Schaltfläche geladen oder neu geladen wird.
Fügen Sie zum Verwenden des Beispiels den Code zu einem Windows Forms Projekt hinzu, und laden Sie die Komponenten aus der Klassenbibliothek in die Toolbox.
Fügen Sie Ihrem Formular einige Schaltflächen hinzu. ButtonDesignerFilterComponent Fügen Sie Ihr Formular hinzu, und sie wird in der Komponentenleiste angezeigt. Dies ButtonDesignerFilterComponent fügt einen ButtonDesignerFilterService, der ITypeDescriptorFilterServiceimplementiert , als Entwurfsmodusdienstanbieter implementiert. Vorhandene oder neue Button Objekte im Formular beginnen mit dem Farbwechsel, nachdem der ButtonDesignerFilterService Designer für jede vorhandene und neue Schaltfläche durch eine ColorCycleButtonDesignerSchaltfläche ersetzt wird. Die Schaltflächen werden farbzyklus ausgeführt, wenn Sie den Mauszeiger über sie verschieben und alternativ den Radlauf fortsetzen oder den Hintergrund und die Vordergrundfarben auf MouseLeave Ereignissen zurücksetzen. Neue Button Objekte werden durch ColorCycleButtonDesigner die FilterAttributes Methode ButtonDesignerFilterService der geladenen Methode gegeben, bis die Entsorgung erfolgt und das ButtonDesignerFilterComponent Original ITypeDescriptorFilterServiceersetzt wird. Die ColorCycleButton Klasse in diesem Beispiel ist eine Button zugeordnete ColorCycleButtonDesigner.
#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;
// Designer for a Button control which cycles the background color.
public ref class ColorCycleButtonDesigner: public System::Windows::Forms::Design::ControlDesigner
{
private:
System::Windows::Forms::Timer^ timer1;
Color initial_bcolor;
Color initial_fcolor;
int r;
int g;
int b;
bool ru;
bool gu;
bool bu;
bool continue_;
public:
ColorCycleButtonDesigner()
{
timer1 = gcnew System::Windows::Forms::Timer;
timer1->Interval = 50;
timer1->Tick += gcnew 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 = gcnew 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:
virtual void OnMouseEnter() override
{
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();
}
}
virtual void OnMouseLeave() override
{
if ( !continue_ )
{
continue_ = true;
timer1->Stop();
}
else
continue_ = false;
this->Control->BackColor = initial_bcolor;
this->Control->ForeColor = initial_fcolor;
}
public:
~ColorCycleButtonDesigner()
{
timer1->Stop();
this->Control->BackColor = initial_bcolor;
this->Control->ForeColor = initial_fcolor;
}
};
// Provides a TypeDescriptorFilterService to add the
// ColorCycleButtonDesigner using a DesignerAttribute.
public ref 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_;
}
virtual bool FilterAttributes( System::ComponentModel::IComponent^ component, System::Collections::IDictionary^ attributes )
{
if ( oldService != nullptr )
oldService->FilterAttributes( component, attributes );
// Creates a designer attribute to compare its TypeID with the TypeID of existing attributes of the component.
DesignerAttribute^ da = gcnew DesignerAttribute( ColorCycleButtonDesigner::typeid );
// 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[ da->TypeId ] = da;
return true;
}
virtual bool FilterEvents( System::ComponentModel::IComponent^ component, System::Collections::IDictionary^ events )
{
if ( oldService != nullptr )
oldService->FilterEvents( component, events );
return true;
}
virtual bool FilterProperties( System::ComponentModel::IComponent^ component, System::Collections::IDictionary^ properties )
{
if ( oldService != nullptr )
oldService->FilterProperties( component, properties );
return true;
}
};
// System.Windows.Forms.Button associated with the ColorCycleButtonDesigner.
[Designer(ColorCycleButtonDesigner::typeid)]
public ref 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 ref class ButtonDesignerFilterComponentDesigner: public System::ComponentModel::Design::ComponentDesigner
{
private:
// Indicates whether the service has been loaded.
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.
virtual void Initialize( System::ComponentModel::IComponent^ component ) override
{
ComponentDesigner::Initialize( component );
// Loads the custom service if it has not been loaded already
LoadService();
// Build list of buttons from Container.Components.
ArrayList^ buttons = gcnew ArrayList;
IEnumerator^ myEnum = this->Component->Site->Container->Components->GetEnumerator();
while ( myEnum->MoveNext() )
{
IComponent^ c = safe_cast<IComponent^>(myEnum->Current);
if ( c->GetType() == System::Windows::Forms::Button::typeid )
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 = safe_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[ i ]) )
{
DesignerAttribute^ da = dynamic_cast<DesignerAttribute^>(ac[ i ]);
if ( da->DesignerTypeName->Substring( da->DesignerTypeName->LastIndexOf( "." ) + 1 )->Equals( "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( IMenuCommandService::typeid ));
if ( imcs == nullptr )
throw gcnew Exception( "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( ISelectionService::typeid ));
if ( iss == nullptr )
throw gcnew Exception( "Could not obtain ISelectionService interface." );
array<IComponent^>^temp0 = {b};
iss->SetSelectedComponents( dynamic_cast<ICollection^>(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( nullptr );
// Refreshes TypeDescriptor properties of
// button to load new attributes from
// ButtonDesignerFilterService.
TypeDescriptor::Refresh( b2 );
b2->Location = p;
b2->Focus();
}
}
}
}
private:
// Loads a ButtonDesignerFilterService ITypeDescriptorFilterService
// to add ColorCycleButtonDesigner designers to each button.
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( ITypeDescriptorFilterService::typeid ));
if ( tdfs != nullptr )
oldservice = tdfs;
// Retrieves an IDesignerHost interface to use to
// remove and add services.
IDesignerHost^ dh = dynamic_cast<IDesignerHost^>(this->Component->Site->GetService( IDesignerHost::typeid ));
if ( dh == nullptr )
throw gcnew Exception( "Could not obtain IDesignerHost interface." );
// Removes standard ITypeDescriptorFilterService.
dh->RemoveService( ITypeDescriptorFilterService::typeid );
// Adds new custom ITypeDescriptorFilterService.
dh->AddService( ITypeDescriptorFilterService::typeid, gcnew ButtonDesignerFilterService );
serviceloaded = true;
}
}
// Removes the custom service and reloads any stored,
// preexisting service.
void RemoveService()
{
IDesignerHost^ dh = dynamic_cast<IDesignerHost^>(this->GetService( IDesignerHost::typeid ));
if ( dh == nullptr )
throw gcnew Exception( "Could not obtain IDesignerHost interface." );
dh->RemoveService( ITypeDescriptorFilterService::typeid );
if ( oldservice != nullptr )
dh->AddService( ITypeDescriptorFilterService::typeid, oldservice );
serviceloaded = false;
}
public:
~ButtonDesignerFilterComponentDesigner()
{
if ( serviceloaded )
RemoveService();
}
};
// Component to host the ButtonDesignerFilterComponentDesigner that loads the
// ButtonDesignerFilterService ITypeDescriptorFilterService.
[Designer(ButtonDesignerFilterComponentDesigner::typeid)]
public ref class ButtonDesignerFilterComponent: public System::ComponentModel::Component
{
public:
ButtonDesignerFilterComponent( System::ComponentModel::IContainer^ container )
{
container->Add( this );
}
ButtonDesignerFilterComponent(){}
};
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.Auto);
// 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()
{}
}
}
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
Public Sub New()
End Sub
End Class
' 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.Auto)
' 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 (tdfs IsNot 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 (oldservice IsNot 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 (oldService IsNot 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 (oldService IsNot 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 (oldService IsNot 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
Hinweise
Die ITypeDescriptorFilterService Schnittstelle bietet eine Schnittstelle, die die Änderung der Eigenschaften, Ereignisse und Klassenebenenattribute einer Komponente zur Entwurfszeit ermöglicht. Diese Änderung erfolgt über den Satz von Deskriptoren, die eine Komponente über eine TypeDescriptor. Der Typdeskriptor abfraget die Website einer Komponente für den ITypeDescriptorFilterService Dienst ab, und falls vorhanden, übergibt der Typdeskriptor alle Metadaten, die er an diesen Dienst gesammelt hat. Der Dienst kann dann die Metadaten ändern, indem vorhandene Merkmale der Komponente hinzugefügt, entfernt und geändert werden.
Beispielsweise können die Eigenschaften einer Komponente über einen Aufruf der FilterProperties Methode geändert werden. Der Filterdienst ruft ein Wörterbuch ab, das Eigenschaftennamen und deren Eigenschaftenbeschreibungen vom Typ PropertyDescriptorenthält. Die Änderungen werden mithilfe der folgenden Logik implementiert.
| Modifikation (Modification) | Implementierung |
|---|---|
| Entfernen | Löschen Sie den entsprechenden Eintrag im Wörterbuch. |
| Addition | Fügen Sie dem Wörterbuch den entsprechenden Eintrag hinzu. |
| Änderung | Rufen Sie vorhandene Eigenschaftendeskriptormethoden auf, ersetzen Sie den zugehörigen Eigenschaftsdeskriptoreintrag oder ersetzen Sie das gesamte Eigenschaftsschlüssel-Wertpaar im Wörterbuch. |
Der Rückgabewert bestimmt FilterProperties , ob diese Gruppe von Eigenschaften behoben ist. Wenn diese Methode zurückgegeben wird true, kann die TypeDescriptor für diese Komponente die Ergebnisse zwischengespeichert werden. Dieser Cache wird beibehalten, bis entweder die Komponente gesammelt wird oder die Refresh Methode des Typdeskriptors aufgerufen wird.
Hinweise für Ausführende
Um die Von einer TypeDescriptorKomponente verfügbar gemachten Memberdeskriptoren zu filtern, implementieren Sie diese Schnittstelle in einer Komponente, und überschreiben Sie die FilterAttributes(IComponent, IDictionary)FilterEvents(IComponent, IDictionary)Methoden dieser Klasse, um Attribute, Ereignisse oder FilterProperties(IComponent, IDictionary) Eigenschaften zu filtern.
Methoden
| FilterAttributes(IComponent, IDictionary) |
Filtert die Attribute, die eine Komponente über einen TypeDescriptor verfügbar macht. |
| FilterEvents(IComponent, IDictionary) |
Filtert die Ereignisse, die eine Komponente über einen TypeDescriptor verfügbar macht. |
| FilterProperties(IComponent, IDictionary) |
Filtert die Eigenschaften, die eine Komponente über einen TypeDescriptor verfügbar macht. |