IDesignerHost Interface

.NET Framework Class Library

Provides an interface for managing designer transactions and components.

For a list of all members of this type, see IDesignerHost Members.

[Visual Basic]
<ComVisible(True)>
Public Interface IDesignerHost
   Inherits IServiceContainer, IServiceProvider
[C#]
[ComVisible(true)]
public interface IDesignerHost : IServiceContainer,
   IServiceProvider
[C++]
[ComVisible(true)]
public __gc __interface IDesignerHost : public IServiceContainer,
   IServiceProvider
[JScript]
public
   ComVisible(true)
interface IDesignerHost implements IServiceContainer,
   IServiceProvider

Remarks

IDesignerHost is an interface that works with the .NET Framework forms designer architecture to provide support for designer transaction and component management.

The .NET Framework does not provide an implementation of this interface. The interface is implemented by development tools that support designers.

Notes to Callers: To obtain an implementation of IDesignerHost from a development environment, call GetService while your component is active in design mode, passing the type of IDesignerHost to request an IDesignerHost service interface.

IDesignerHost provides the following members related to designer state:

The Loading property indicates whether a designer or document is being loaded.
The Activated event occurs when a designer is activated before display.
The Deactivated event occurs when a designer is deactivated.
The LoadComplete event occurs after a document is loaded.
The Activate method activates the designer.

IDesignerHost provides the following members related to managing components:

The Container property indicates the container for the designer host.
The RootComponent property indicates the base class for the root component.
The RootComponentClassName property indicates the name of the class of the root component.
The CreateComponent method creates the specified type of component.
The DestroyComponent method destroys the specified component.
The GetDesigner method gets the designer associated with a specified component.
The GetType method gets an instance of the type with the specified name.

IDesignerHost provides the following members related to managing transactions:

The InTransaction property indicates whether the designer is in a transaction.
The TransactionDescription property indicates the current transaction description.
The TransactionClosed event occurs when a transaction has been completed.
The TransactionClosing event occurs when a transaction is about to be completed.
The TransactionOpened event occurs when a transaction has begun.
The TransactionOpening event occurs when a transaction is about to begin.
The CreateTransaction method creates and returns a new transaction.

Example

[Visual Basic, C#, C++] The following example code demonstrates how to obtain the IDesignerHost service interface from a designer or sited component.

[Visual Basic] 
' Requests an IDesignerHost service from the design time environment using Component.Site.GetService()
Dim host As IDesignerHost = CType(Me.Component.Site.GetService(GetType(IDesignerHost)), IDesignerHost)

[C#] 
// Requests an IDesignerHost service from the design time environment using Component.Site.GetService()
IDesignerHost dh = (IDesignerHost) this.Component.Site.GetService(typeof(IDesignerHost));            

[C++] 
// Requests an IDesignerHost service from the design time environment using Component.Site.GetService()
IDesignerHost* dh = static_cast<IDesignerHost*>(this->Component->Site->GetService(__typeof(IDesignerHost)));

[Visual Basic, C#, C++] The following example code demonstrates using the IDesignerHost interface to list project components.

[Visual Basic] 
Imports System
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Drawing
Imports System.Windows.Forms

Namespace IDesignerHostExample
   
   ' IDesignerHostExampleComponent is a component associated 
   ' with the IDesignerHostExampleDesigner that demonstrates 
   ' acquisition and use of the IDesignerHost service 
   ' to list project components.
    <DesignerAttribute(GetType(IDesignerHostExampleDesigner))> _
    Public Class IDesignerHostExampleComponent
        Inherits System.ComponentModel.Component

        Public Sub New()
        End Sub 'New

        Protected Overloads Sub Dispose(ByVal disposing As Boolean)
            MyBase.Dispose(disposing)
        End Sub 
    End Class 

    ' You can double-click the component of a IDesignerHostExampleDesigner
    ' to show a form containing a listbox that lists the name and type 
    ' of each component or control in the current design-time project.
    Public Class IDesignerHostExampleDesigner
        Implements IDesigner
        Private component_ As System.ComponentModel.IComponent

        Public Sub New()
        End Sub 'New

        Public Sub DoDefaultAction() Implements IDesigner.DoDefaultAction
            ListComponents()
        End Sub

        Public Sub Initialize(ByVal component As System.ComponentModel.IComponent) Implements IDesigner.Initialize
            Me.component_ = component
            MessageBox.Show("Double-click the IDesignerHostExample component to view a list of project components.")
        End Sub

        ' Displays a list of components in the current design 
        ' document when the default action of the designer is invoked.
        Private Sub ListComponents()
            Dim listform As New DesignerHostListForm()
            ' Obtain an IDesignerHost service from the design environment.
            Dim host As IDesignerHost = CType(Me.component.Site.GetService(GetType(IDesignerHost)), IDesignerHost)
            ' Get the project components container (control containment depends on Controls collections)
            Dim container As IContainer = host.Container
            ' Add each component's type name and name to the list box.
            Dim comp As Component
            For Each comp In container.Components
                listform.listBox1.Items.Add((comp.GetType().Name + " : " + component.Site.Name))
            Next comp
            ' Display the form.
            listform.ShowDialog()
        End Sub 

        Public ReadOnly Property Component() As System.ComponentModel.IComponent Implements IDesigner.Component
            Get
                Return component_
            End Get
        End Property

        Public ReadOnly Property Verbs() As System.ComponentModel.Design.DesignerVerbCollection Implements IDesigner.Verbs
            Get
                Dim dvc As New DesignerVerbCollection()
                dvc.Add(New DesignerVerb("List Components", New EventHandler(AddressOf ListHandler)))
                Return dvc
            End Get
        End Property

        Private Sub ListHandler(ByVal sender As Object, ByVal e As EventArgs)
            ListComponents()
        End Sub 

        Public Sub Dispose() Implements IDisposable.Dispose
        End Sub 
    End Class 
    _ 

    ' Provides a form containing a list box that can display 
    ' a list of project components.
    Public Class DesignerHostListForm
        Inherits System.Windows.Forms.Form
        Public listBox1 As System.Windows.Forms.ListBox
        Private ok_button As System.Windows.Forms.Button

        Public Sub New()
            Me.Name = "DesignerHostListForm"
            Me.Text = "List of design-time project components"
            Me.SuspendLayout()
            Me.listBox1 = New System.Windows.Forms.ListBox()
            Me.listBox1.Location = New System.Drawing.Point(8, 8)
            Me.listBox1.Name = "listBox1"
            Me.listBox1.Size = New System.Drawing.Size(385, 238)
            Me.listBox1.TabIndex = 0
            Me.listBox1.Anchor = (((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom) _
            Or System.Windows.Forms.AnchorStyles.Left) Or System.Windows.Forms.AnchorStyles.Right)
            Me.ok_button = New System.Windows.Forms.Button()
            Me.ok_button.DialogResult = System.Windows.Forms.DialogResult.OK
            Me.ok_button.Location = New System.Drawing.Point(232, 256)
            Me.ok_button.Name = "ok_button"
            Me.ok_button.TabIndex = 1
            Me.ok_button.Text = "OK"
            Me.ok_button.Anchor = (System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Right)
            Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
            Me.ClientSize = New System.Drawing.Size(400, 285)
            Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.ok_button, Me.listBox1})
            Me.ResumeLayout(False)
        End Sub 

        Protected Overloads Sub Dispose(ByVal disposing As Boolean)
            MyBase.Dispose(disposing)
        End Sub 
    End Class 
End Namespace 

[C#] 
using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Drawing;
using System.Windows.Forms;

namespace IDesignerHostExample
{    
    // IDesignerHostExampleComponent is a component associated 
    // with the IDesignerHostExampleDesigner that demonstrates 
    // acquisition and use of the IDesignerHost service 
    // to list project components.
    [DesignerAttribute(typeof(IDesignerHostExampleDesigner))]
    public class IDesignerHostExampleComponent : System.ComponentModel.Component
    {
        public IDesignerHostExampleComponent()
        {}

        protected override void Dispose( bool disposing )
        {
            base.Dispose( disposing );
        }
    }

    // You can double-click the component of an IDesignerHostExampleDesigner 
    // to show a form containing a listbox that lists the name and type 
    // of each component or control in the current design-time project.
    public class IDesignerHostExampleDesigner : IDesigner
    {
        private System.ComponentModel.IComponent component;

        public IDesignerHostExampleDesigner()
        {}

        public void DoDefaultAction()
        {
            ListComponents();
        }

        public void Initialize(System.ComponentModel.IComponent component)
        {
            this.component = component;
            MessageBox.Show("Double-click the IDesignerHostExample component to view a list of project components.");
        }

        // Displays a list of components in the current design 
        // document when the default action of the designer is invoked.
        private void ListComponents()
        {            
            DesignerHostListForm listform = new DesignerHostListForm();
            // Obtain an IDesignerHost service from the design environment.
            IDesignerHost host = (IDesignerHost)this.component.Site.GetService(typeof(IDesignerHost));
            // Get the project components container (control containment depends on Controls collections)
            IContainer container = host.Container;
            // Add each component's type name and name to the list box.
            foreach(IComponent component in container.Components)
            {
                listform.listBox1.Items.Add(component.GetType().Name + " : " + component.Site.Name);
            }
            // Display the form.
            listform.ShowDialog();
        }

        public System.ComponentModel.IComponent Component
        {
            get
            {
                return this.component;
            }
        }

        public System.ComponentModel.Design.DesignerVerbCollection Verbs
        {
            get
            {
                DesignerVerbCollection dvc = new DesignerVerbCollection();
                dvc.Add( new DesignerVerb("List Components", new EventHandler(ListHandler)) );
                return dvc;
            }
        }

        private void ListHandler(object sender, EventArgs e)
        {
            ListComponents();
        }

        public void Dispose() {    }
    }

    // Provides a form containing a listbox that can display 
    // a list of project components.
    public class DesignerHostListForm : System.Windows.Forms.Form
    {
        public System.Windows.Forms.ListBox listBox1;
        private System.Windows.Forms.Button ok_button;
        
        public DesignerHostListForm()
        {
            this.Name = "DesignerHostListForm";
            this.Text = "List of design-time project components";
            this.SuspendLayout();
            this.listBox1 = new System.Windows.Forms.ListBox();                        
            this.listBox1.Location = new System.Drawing.Point(8, 8);
            this.listBox1.Name = "listBox1";
            this.listBox1.Size = new System.Drawing.Size(385, 238);
            this.listBox1.TabIndex = 0;    
            this.listBox1.Anchor = (((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
                | System.Windows.Forms.AnchorStyles.Left) 
                | System.Windows.Forms.AnchorStyles.Right);        
            this.ok_button = new System.Windows.Forms.Button();
            this.ok_button.DialogResult = System.Windows.Forms.DialogResult.OK;
            this.ok_button.Location = new System.Drawing.Point(232, 256);
            this.ok_button.Name = "ok_button";
            this.ok_button.TabIndex = 1;
            this.ok_button.Text = "OK";
            this.ok_button.Anchor = (System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right);
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(400, 285);
            this.Controls.AddRange(new System.Windows.Forms.Control[] { this.ok_button, this.listBox1 });
            this.ResumeLayout(false);    
        }

        protected override void Dispose( bool disposing )
        {            
            base.Dispose( disposing );
        }    
    }
}

[C++] 
#using <mscorlib.dll>
#using <System.Windows.Forms.dll>
#using <System.Drawing.dll>
#using <System.dll>
using namespace System;
using namespace System::ComponentModel;
using namespace System::ComponentModel::Design;
using namespace System::Drawing;
using namespace System::Windows::Forms;

namespace IDesignerHostExample
{    
    // Provides a form containing a listbox that can display 
    // a list of project components.
public __gc class DesignerHostListForm : public System::Windows::Forms::Form
{
public:
    System::Windows::Forms::ListBox* listBox1;
private:
    System::Windows::Forms::Button* ok_button;

public:
    DesignerHostListForm()
    {
        this->Name = S"DesignerHostListForm";
        this->Text = S"List of design-time project components";
        this->SuspendLayout();
        this->listBox1 = new System::Windows::Forms::ListBox();                        
        this->listBox1->Location = System::Drawing::Point(8, 8);
        this->listBox1->Name = S"listBox1";
        this->listBox1->Size = System::Drawing::Size(385, 238);
        this->listBox1->TabIndex = 0;    
        this->listBox1->Anchor = static_cast<AnchorStyles>(((System::Windows::Forms::AnchorStyles::Top | System::Windows::Forms::AnchorStyles::Bottom) 
            | System::Windows::Forms::AnchorStyles::Left) 
            | System::Windows::Forms::AnchorStyles::Right);        
        this->ok_button = new System::Windows::Forms::Button();
        this->ok_button->DialogResult = System::Windows::Forms::DialogResult::OK;
        this->ok_button->Location = System::Drawing::Point(232, 256);
        this->ok_button->Name = S"ok_button";
        this->ok_button->TabIndex = 1;
        this->ok_button->Text = S"OK";
        this->ok_button->Anchor = static_cast<AnchorStyles>(System::Windows::Forms::AnchorStyles::Bottom | System::Windows::Forms::AnchorStyles::Right);
        this->AutoScaleBaseSize = System::Drawing::Size(5, 13);
        this->ClientSize = System::Drawing::Size(400, 285);

        System::Windows::Forms::Control* temp2 [] = {this->ok_button, this->listBox1};

        this->Controls->AddRange(temp2);
        this->ResumeLayout(false);    
    }

protected:
    void Dispose( bool disposing )
    {            
        Form::Dispose( disposing );
    }    
};

// You can double-click the component of an IDesignerHostExampleDesigner 
// to show a form containing a listbox that lists the name and type 
// of each component or control in the current design-time project.
public __gc class IDesignerHostExampleDesigner : public IDesigner
{
private:
    System::ComponentModel::IComponent* component;

public:
    IDesignerHostExampleDesigner()
    {}

    void DoDefaultAction()
    {
        ListComponents();
    }

    void Initialize(System::ComponentModel::IComponent* component)
    {
        this->component = component;
        MessageBox::Show(S"Double-click the IDesignerHostExample component to view a list of project components.");
    }

    // Displays a list of components in the current design 
    // document when the default action of the designer is invoked.
private:
    void ListComponents()
    {            
        DesignerHostListForm* listform = new DesignerHostListForm();
        // Obtain an IDesignerHost service from the design environment.
        IDesignerHost* host = dynamic_cast<IDesignerHost*>(this->component->Site->GetService(__typeof(IDesignerHost)));
        // Get the project components container (control containment depends on Controls collections)
        IContainer* container = host->Container;
        // Add each component's type name and name to the list box.
        System::Collections::IEnumerator* myEnum = container->Components->GetEnumerator();
        while (myEnum->MoveNext())
        {
            IComponent* component = __try_cast<IComponent*>(myEnum->Current);
            listform->listBox1->Items->Add(String::Concat( component->GetType()->Name, S" : ", component->Site->Name ));
        }
        // Display the form.
        listform->ShowDialog();
    }

public:
    __property System::ComponentModel::IComponent* get_Component()
    {
        return this->component;
    }

    __property System::ComponentModel::Design::DesignerVerbCollection* get_Verbs()
    {
        DesignerVerbCollection* dvc = new DesignerVerbCollection();
        dvc->Add( new DesignerVerb(S"List Components", new EventHandler(this, &IDesignerHostExampleDesigner::ListHandler)) );
        return dvc;
    }

private:
    void ListHandler(Object* /*sender*/, EventArgs* /*e*/)
    {
        ListComponents();
    }

public:
    void Dispose() {    }
};

// IDesignerHostExampleComponent is a component associated 
// with the IDesignerHostExampleDesigner that demonstrates 
// acquisition and use of the IDesignerHost service 
// to list project components.
[DesignerAttribute(__typeof(IDesignerHostExampleDesigner))]
public __gc class IDesignerHostExampleComponent : public System::ComponentModel::Component
{
public:
    IDesignerHostExampleComponent()
    {}

protected:
    void Dispose( bool disposing )
    {
        Component::Dispose( disposing );
    }
};
}

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button in the upper-left corner of the page.

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)

Remarks

Example

Requirements

See Also