ControlPersister Class

Definition

public ref class ControlPersister sealed

public sealed class ControlPersister

type ControlPersister = class

Public NotInheritable Class ControlPersister

Inheritance

Object

ControlPersister

Examples

#using <System.dll>
#using <System.Drawing.dll>
#using <System.Web.dll>
#using <System.Design.dll>
#using <System.Windows.Forms.dll>

using namespace System;
using namespace System::Drawing;
using namespace System::Drawing::Design;
using namespace System::IO;
using namespace System::Web::UI;
using namespace System::Web::UI::Design;
using namespace System::Web::UI::WebControls;
using namespace System::ComponentModel;
using namespace System::ComponentModel::Design;
using namespace System::Windows::Forms;
using namespace System::Windows::Forms::Design;

// Provides a form with a multiline text box display.
private ref class StringDisplayForm: public Form
{
public:
   StringDisplayForm( String^ displayText )
   {
      this->Size = System::Drawing::Size( 400, 400 );
      this->Text = "Control Persistence String";
      this->SuspendLayout();
      System::Windows::Forms::TextBox^ tbox = gcnew System::Windows::Forms::TextBox;
      tbox->Multiline = true;
      tbox->Size = System::Drawing::Size( this->Width - 40, this->Height - 90 );
      tbox->Text = displayText;
      this->Controls->Add( tbox );
      System::Windows::Forms::Button^ okButton = gcnew System::Windows::Forms::Button;
      okButton->Text = "OK";
      okButton->Size = System::Drawing::Size( 80, 24 );
      okButton->Location = Point(this->Width - 100,this->Height - 60);
      okButton->Anchor = AnchorStyles(AnchorStyles::Bottom | AnchorStyles::Right);
      okButton->DialogResult = ::DialogResult::OK;
      this->Controls->Add( okButton );
      this->ResumeLayout();
   }

};

// Provides a form with a list for selection.
private ref class ControlSelectionForm: public Form
{
private:
   array<System::Web::UI::Control^>^controlArray;

public:
   System::Windows::Forms::ListBox^ controlList;
   ControlSelectionForm( array<System::Web::UI::Control^>^controlArray )
   {
      this->controlArray = controlArray;
      this->Size = System::Drawing::Size( 400, 500 );
      this->Text = "Control Persister Selection Form";
      this->SuspendLayout();
      System::Windows::Forms::Label ^ label1 = gcnew System::Windows::Forms::Label;
      label1->Text = "Select the control to persist:";
      label1->Size = System::Drawing::Size( 240, 20 );
      label1->Location = Point(10,10);
      this->Controls->Add( label1 );
      controlList = gcnew System::Windows::Forms::ListBox;
      controlList->Size = System::Drawing::Size( 370, 400 );
      controlList->Location = Point(10,30);
      controlList->Anchor = AnchorStyles(AnchorStyles::Left | AnchorStyles::Top | AnchorStyles::Bottom | AnchorStyles::Right);
      this->Controls->Add( controlList );
      System::Windows::Forms::Button^ okButton = gcnew System::Windows::Forms::Button;
      okButton->Text = "OK";
      okButton->Size = System::Drawing::Size( 80, 24 );
      okButton->Location = Point(this->Width - 100,this->Height - 60);
      okButton->Anchor = AnchorStyles(AnchorStyles::Bottom | AnchorStyles::Right);
      okButton->DialogResult = ::DialogResult::OK;
      this->Controls->Add( okButton );
      System::Windows::Forms::Button^ cancelButton = gcnew System::Windows::Forms::Button;
      cancelButton->Text = "Cancel";
      cancelButton->Size = System::Drawing::Size( 80, 24 );
      cancelButton->Location = Point(this->Width - 200,this->Height - 60);
      cancelButton->Anchor = AnchorStyles(AnchorStyles::Bottom | AnchorStyles::Right);
      cancelButton->DialogResult = ::DialogResult::Cancel;
      this->Controls->Add( cancelButton );
      for ( int i = 0; i < controlArray->Length; i++ )
         controlList->Items->Add( controlArray[ i ]->UniqueID );
      this->ResumeLayout();
   }
};

// Provides a form with a multiline text box for input.
private ref class StringInputForm: public Form
{
public:
   System::Windows::Forms::TextBox^ tbox;
   StringInputForm()
   {
      this->Size = System::Drawing::Size( 400, 400 );
      this->Text = "Input Control Persistence String";
      this->SuspendLayout();
      tbox = gcnew System::Windows::Forms::TextBox;
      tbox->Multiline = true;
      tbox->Size = System::Drawing::Size( this->Width - 40, this->Height - 90 );
      tbox->Text = "";
      this->Controls->Add( tbox );
      System::Windows::Forms::Button^ okButton = gcnew System::Windows::Forms::Button;
      okButton->Text = "OK";
      okButton->Size = System::Drawing::Size( 80, 24 );
      okButton->Location = Point(this->Width - 100,this->Height - 60);
      okButton->Anchor = AnchorStyles(AnchorStyles::Bottom | AnchorStyles::Right);
      okButton->DialogResult = ::DialogResult::OK;
      this->Controls->Add( okButton );
      System::Windows::Forms::Button^ cancelButton = gcnew System::Windows::Forms::Button;
      cancelButton->Text = "Cancel";
      cancelButton->Size = System::Drawing::Size( 80, 24 );
      cancelButton->Location = Point(this->Width - 200,this->Height - 60);
      cancelButton->Anchor = AnchorStyles(AnchorStyles::Bottom | AnchorStyles::Right);
      cancelButton->DialogResult = ::DialogResult::Cancel;
      this->Controls->Add( cancelButton );
      this->ResumeLayout();
   }
};


// Web control designer provides an interface
// to use the ControlPersister and ControlParser.
public ref class ControlParserPersisterDesigner: public System::Web::UI::Design::ControlDesigner
{
public:
   ControlParserPersisterDesigner()
      : ControlDesigner()
   {}

   property System::ComponentModel::Design::DesignerVerbCollection^ Verbs 
   {
      // Provides designer verb menu commands to
      // persist a control and to load a persisted control.
      [System::Security::Permissions::PermissionSetAttribute(System::Security::Permissions::SecurityAction::Demand, Name="FullTrust")]
      virtual System::ComponentModel::Design::DesignerVerbCollection^ get() override
      {
         DesignerVerbCollection^ dvc = gcnew DesignerVerbCollection;
         dvc->Add( gcnew DesignerVerb( "Load Persisted Control...",gcnew EventHandler( this, &ControlParserPersisterDesigner::loadPersistedControl ) ) );
         dvc->Add( gcnew DesignerVerb( "Parse and Save Control...",gcnew EventHandler( this, &ControlParserPersisterDesigner::saveControl ) ) );
         return dvc;
      }

   }

private:

   // Displays a textbox form to receive an HTML
   // String* that represents a control, and creates
   // a toolbox item for the control, if not already
   // present in the selected toolbox category.
   void loadPersistedControl( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      // Display a StringInputForm to obtain a persisted control String*.
      StringInputForm^ inputForm = gcnew StringInputForm;
      if ( inputForm->ShowDialog() != DialogResult::OK )
            return;

      if ( inputForm->tbox->Text->Length < 2 )
            return;

      // Obtain an IDesignerHost* for the design-mode document.
      IDesignerHost^ host = dynamic_cast<IDesignerHost^>(this->Component->Site->GetService( IDesignerHost::typeid ));
      
      // Create a Web control from the persisted control String*.
      System::Web::UI::Control^ ctrl = ControlParser::ParseControl( host, inputForm->tbox->Text->Trim() );

      // Create a Web control toolbox item for the type of the control
      WebControlToolboxItem^ item = gcnew WebControlToolboxItem( ctrl->GetType() );
      
      // Add the Web control toolbox item to the toolbox
      IToolboxService^ toolService = dynamic_cast<IToolboxService^>(this->Component->Site->GetService( IToolboxService::typeid ));
      if ( toolService != nullptr )
            toolService->AddToolboxItem( item );
      else
            throw gcnew Exception( "IToolboxService* was not found." );
   }

   // Displays a list of controls in the project, if any,
   // and displays the HTML representing the persisted, selected control.
   void saveControl( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      // Get the collection of components in the current
      // design mode document.
      ComponentCollection^ documentComponents = this->Component->Site->Container->Components;

      // Filter the components to those that derive from the
      // System::Web::UI::Control class.
      // Create an IComponent* array of the maximum possible length needed.
      array<IComponent^>^filterArray = gcnew array<IComponent^>(documentComponents->Count);

      // Count the total qualifying components.
      int total = 0;
      for ( int i = 0; i < documentComponents->Count; i++ )
      {
         // If the component derives from System::Web::UI::Control,
         // copy a reference to the control to the filterArray
         // array and increment the control count.
         if ( System::Web::UI::Control::typeid->IsAssignableFrom( documentComponents[i]->GetType() ) )
         {
            if ( (dynamic_cast<System::Web::UI::Control^>(documentComponents[i]))->UniqueID != nullptr )
            {
               filterArray[total] = documentComponents[i];
               total++;
            }
         }

      }
      if ( total == 0 )
            throw gcnew Exception( "Document contains no System::Web::UI::Control components." );

      // Move the components that derive from System::Web::UI::Control to a
      // new array of the correct size.
      array<System::Web::UI::Control^>^controlArray = gcnew array<System::Web::UI::Control^>(total);
      for ( int i = 0; i < total; i++ )
         controlArray[i] = dynamic_cast<System::Web::UI::Control^>(filterArray[i]);

      // Create a ControlSelectionForm to provide a persistence
      // configuration interface.
      ControlSelectionForm^ selectionForm = gcnew ControlSelectionForm( controlArray );

      // Display the form.
      if ( selectionForm->ShowDialog() != DialogResult::OK )
            return;

      // Validate the selection.
      if ( selectionForm->controlList->SelectedIndex == -1 )
            throw gcnew Exception( "You must select a control to persist." );

      // Parse the selected control.
      String^ persistedData = ControlPersister::PersistControl( controlArray[ selectionForm->controlList->SelectedIndex ] );

      // Display the control persistence String* in a text box.
      StringDisplayForm^ displayForm = gcnew StringDisplayForm( persistedData );
      displayForm->ShowDialog();
   }
};

// Simple text display control hosts the ControlParserPersisterDesigner.

[DesignerAttribute(ControlParserPersisterDesigner::typeid,IDesigner::typeid)]
public ref class ControlParserPersisterDesignerControl: public WebControl
{
private:
   String^ text;

public:

   property String^ Text 
   {
      [Bindable(true),
      Category("Appearance"),
      DefaultValue("")]
      String^ get()
      {
         return text;
      }

      void set( String^ value )
      {
         text = value;
      }
   }
   ControlParserPersisterDesignerControl()
      : WebControl()
   {
      text = "Right-click here to access control persistence methods in design mode";
   }

protected:
   virtual void Render( HtmlTextWriter^ output ) override
   {
      output->Write( Text );
   }
};

using System;
using System.Drawing;
using System.Drawing.Design;
using System.Web.UI;
using System.Web.UI.Design;
using System.Web.UI.WebControls;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Windows.Forms;
using System.Windows.Forms.Design;

namespace ControlParserPersisterDesignerControl_CS
{
    // Web control designer provides an interface 
    //   to use the ControlPersister and ControlParser.
    // The DesignerActionListCollection must run under "FullTrust",
    //   so you must also require your designer to run under "FullTrust".
    [System.Security.Permissions.PermissionSetAttribute(
        System.Security.Permissions.SecurityAction.InheritanceDemand, 
        Name = "FullTrust")]
    [System.Security.Permissions.PermissionSetAttribute(
        System.Security.Permissions.SecurityAction.Demand, 
        Name = "FullTrust")]
    public class ControlParserPersisterDesigner :
        System.Web.UI.Design.ControlDesigner
    {
        private DesignerActionListCollection _actLists = null;

        public ControlParserPersisterDesigner()
            : base()
        {}

        // Creates designer menu commands to persist
        // a control and to load a persisted control.
        public override DesignerActionListCollection ActionLists
        {
            get
            {
                if (_actLists == null)
                {
                    _actLists = new DesignerActionListCollection();
                    _actLists.AddRange(base.ActionLists);
                    _actLists.Add(new ParserActionList(this));
                }
                return _actLists;
            }
        }

        // A custom class for the DesignerActionList
        private class ParserActionList : DesignerActionList
        {
            private ControlParserPersisterDesigner _parent;
            private DesignerActionItemCollection _items;

            public ParserActionList(ControlParserPersisterDesigner parent) : 
                base(parent.Component)
            {
                _parent = parent;
            }

            public override DesignerActionItemCollection GetSortedActionItems()
            {
                if (_items == null)
                {
                    // Create the collection
                    _items = new DesignerActionItemCollection();

                    _items.Add(new DesignerActionMethodItem(this, "saveControl", "Parse and Save Control...", true));
                    _items.Add(new DesignerActionMethodItem(this, "loadPersistedControl", "Load Persisted Control...", true));
                }
                return _items;
            }

            // Displays a list of controls in the project, if any,
            // and displays the HTML markup for the selected control.       
            private void saveControl()
            {
                // Get the collection of components in the current 
                // design mode document.
                ComponentCollection documentComponents =
                    this.Component.Site.Container.Components;

                // Filter the components to those that derive from the 
                // System.Web.UI.Control class.

                // Create an IComponent array of the maximum possible length needed.
                IComponent[] filterArray = new IComponent[documentComponents.Count];

                // Count the total qualifying components.
                int total = 0;
                for (int i = 0; i < documentComponents.Count; i++)
                {
                    // If the component derives from System.Web.UI.Control, 
                    // copy a reference to the control to the filterArray 
                    // array and increment the control count.
                    if (typeof(System.Web.UI.Control).IsAssignableFrom(
                        documentComponents[i].GetType()))
                    {
                        if (((System.Web.UI.Control)documentComponents[i]).UniqueID
                            != null)
                        {
                            filterArray[total] = documentComponents[i];
                            total++;
                        }
                    }
                }

                if (total == 0)
                    throw new Exception(
                        "Document contains no System.Web.UI.Control components.");

                // Move the components that derive from System.Web.UI.Control to a 
                // new array of the correct size.
                System.Web.UI.Control[] controlArray =
                    new System.Web.UI.Control[total];
                for (int i = 0; i < total; i++)
                    controlArray[i] = (System.Web.UI.Control)filterArray[i];

                // Create a ControlSelectionForm to select a control.
                ControlSelectionForm selectionForm =
                    new ControlSelectionForm(controlArray);

                // Display the form.
                if (selectionForm.ShowDialog() != DialogResult.OK)
                    return;

                // Validate the selection.
                if (selectionForm.controlList.SelectedIndex == -1)
                    throw new Exception("You must select a control to persist.");

                // Parse the selected control into a persistence string.
                string persistedData = ControlPersister.PersistControl(
                    controlArray[selectionForm.controlList.SelectedIndex]);

                // Display the persistence string in a text box.
                StringDisplayForm displayForm =
                    new StringDisplayForm(persistedData);
                displayForm.ShowDialog();
            }

            // Displays a textbox form to receive an HTML 
            // string that represents a control, and creates
            // a toolbox item for the control, if not already
            // present in the selected toolbox category.
            private void loadPersistedControl()
            {
                // Display a StringInputForm to obtain a persisted control string.
                StringInputForm inputForm = new StringInputForm();

                if (inputForm.ShowDialog() != DialogResult.OK)
                    return;
                if (inputForm.TBox.Text.Length < 2)
                    return;

                // Obtain an IDesignerHost for the design-mode document.
                IDesignerHost host = (IDesignerHost)
                    this.Component.Site.GetService(typeof(IDesignerHost));

                // Create a Web control from the HTML markup.
                System.Web.UI.Control ctrl =
                    ControlParser.ParseControl(host, inputForm.TBox.Text.Trim());

                // Create a Web control toolbox item for the type of the control
                System.Web.UI.Design.WebControlToolboxItem item =
                    new System.Web.UI.Design.WebControlToolboxItem(ctrl.GetType());

                // Add the Web control toolbox item to the toolbox
                IToolboxService toolService = (IToolboxService)
                    this.Component.Site.GetService(typeof(IToolboxService));
                if (toolService != null)
                    toolService.AddToolboxItem(item);
                else
                    throw new Exception("IToolboxService was not found.");
            }
        }
    }

    // Simple text display control hosts the ControlParserPersisterDesigner.
    [DesignerAttribute(typeof(ControlParserPersisterDesigner),
         typeof(IDesigner))]
    public class ControlParserPersisterDesignerControl :
        System.Web.UI.WebControls.WebControl
    {
        private string _text;

        [Bindable(true),
            Category("Appearance"),
            DefaultValue("")]
        public string Text
        {
            get { return _text; }
            set { _text = value; }
        }

        public ControlParserPersisterDesignerControl()
            : base()
        {
            _text = "Right-click here to access control persistence " +
                "methods in design mode";
        }

        protected override void Render(HtmlTextWriter output)
        {
            output.Write(Text);
        }
    }

    // Provides a form with a list for selection.
    internal class ControlSelectionForm : Form
    {
        private System.Web.UI.Control[] controlArray;
        public System.Windows.Forms.ListBox controlList;

        public ControlSelectionForm(System.Web.UI.Control[] controlArray)
        {
            this.controlArray = controlArray;

            this.Size = new Size(400, 500);
            this.Text = "Control Selection Form";

            this.SuspendLayout();

            System.Windows.Forms.Label label1 =
                new System.Windows.Forms.Label();
            label1.Text = "Select a control to parse:";
            label1.Size = new Size(240, 20);
            label1.Location = new Point(10, 10);
            this.Controls.Add(label1);

            controlList = new System.Windows.Forms.ListBox();
            controlList.Size = new Size(370, 400);
            controlList.Location = new Point(10, 30);
            controlList.Anchor = AnchorStyles.Left | AnchorStyles.Top |
                AnchorStyles.Bottom | AnchorStyles.Right;
            this.Controls.Add(controlList);

            System.Windows.Forms.Button okButton =
                new System.Windows.Forms.Button();
            okButton.Text = "OK";
            okButton.Size = new Size(80, 24);
            okButton.Location =
                new Point(this.Width - 100, this.Height - 60);
            okButton.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
            okButton.DialogResult = DialogResult.OK;
            this.Controls.Add(okButton);

            System.Windows.Forms.Button cancelButton =
                new System.Windows.Forms.Button();
            cancelButton.Text = "Cancel";
            cancelButton.Size = new Size(80, 24);
            cancelButton.Location =
                new Point(this.Width - 200, this.Height - 60);
            cancelButton.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
            cancelButton.DialogResult = DialogResult.Cancel;
            this.Controls.Add(cancelButton);

            for (int i = 0; i < controlArray.Length; i++)
                controlList.Items.Add(controlArray[i].UniqueID);

            this.ResumeLayout();
        }
    }

    // Provides a form with a multiline text box display.
    internal class StringDisplayForm : Form
    {
        private System.Windows.Forms.TextBox tbox = 
            new System.Windows.Forms.TextBox();

        public System.Windows.Forms.TextBox TBox
        {
            get { return tbox; }
            set { tbox = value; }
        }

        public StringDisplayForm(string displayText)
        {
            this.Size = new Size(400, 300);
            this.Text = "Control Persistence String";

            this.SuspendLayout();
            TBox.Multiline = true;
            TBox.Size = new Size(this.Width - 40, this.Height - 90);
            TBox.Text = displayText;
            this.Controls.Add(TBox);

            System.Windows.Forms.Button okButton =
                new System.Windows.Forms.Button();
            okButton.Text = "OK";
            okButton.Size = new Size(80, 24);
            okButton.Location =
                new Point(this.Width - 100, this.Height - 60);
            okButton.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
            okButton.DialogResult = DialogResult.OK;
            this.Controls.Add(okButton);

            this.ResumeLayout();
        }
    }

    // Provides a form with a multiline text box for input.
    internal class StringInputForm : System.Windows.Forms.Form
    {
        private System.Windows.Forms.TextBox tbox = 
            new System.Windows.Forms.TextBox();

        public System.Windows.Forms.TextBox TBox
        {
            get { return tbox; }
        }

        public StringInputForm()
        {
            this.Size = new Size(400, 300);
            this.Text = "Input Control Persistence String";

            this.SuspendLayout();
            tbox = new System.Windows.Forms.TextBox();
            tbox.Multiline = true;
            tbox.Size = new Size(this.Width - 40, this.Height - 90);
            tbox.Text = "";
            this.Controls.Add(tbox);

            System.Windows.Forms.Button okButton =
                new System.Windows.Forms.Button();
            okButton.Text = "OK";
            okButton.Size = new Size(80, 24);
            okButton.Location =
                new Point(this.Width - 100, this.Height - 60);
            okButton.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
            okButton.DialogResult = DialogResult.OK;
            this.Controls.Add(okButton);

            System.Windows.Forms.Button cancelButton =
                new System.Windows.Forms.Button();
            cancelButton.Text = "Cancel";
            cancelButton.Size = new Size(80, 24);
            cancelButton.Location =
                new Point(this.Width - 200, this.Height - 60);
            cancelButton.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
            cancelButton.DialogResult = DialogResult.Cancel;
            this.Controls.Add(cancelButton);

            this.ResumeLayout();
        }
    }
}

Imports System.Drawing
Imports System.Drawing.Design
Imports System.Web.UI
Imports System.Web.UI.Design
Imports System.Web.UI.WebControls
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Windows.Forms
Imports System.Windows.Forms.Design

Namespace ControlParserPersisterDesignerControl_VB

    ' Web control designer provides an interface 
    '   to use the ControlPersister and ControlParser.
    ' The DesignerActionListCollection must run under "FullTrust",
    '   so you must also require your designer to run under "FullTrust".
    <System.Security.Permissions.PermissionSetAttribute( _
        System.Security.Permissions.SecurityAction.InheritanceDemand, _
        Name:="FullTrust")> _
    <System.Security.Permissions.PermissionSetAttribute( _
         Security.Permissions.SecurityAction.Demand, _
         Name:="FullTrust")> _
    Public Class ControlParserPersisterDesigner
        Inherits System.Web.UI.Design.ControlDesigner

        Private _actLists As DesignerActionListCollection

        Public Sub New()
        End Sub

        ' Creates designer menu commands to persist 
        ' a control and to load a persisted control.
        Public Overrides ReadOnly Property ActionLists() As System.ComponentModel.Design.DesignerActionListCollection
            Get
                If IsNothing(_actLists) Then
                    _actLists = New DesignerActionListCollection()
                    _actLists.AddRange(MyBase.ActionLists)
                    _actLists.Add(New ParserActionList(Me))
                End If

                Return _actLists
            End Get
        End Property
        'Public Overrides ReadOnly Property Verbs() _
        'As System.ComponentModel.Design.DesignerVerbCollection
        '    Get
        '        Dim dvc As New DesignerVerbCollection()
        '        dvc.Add(New DesignerVerb("Load Persisted Control...", _
        '            New EventHandler(AddressOf Me.loadPersistedControl)))
        '        dvc.Add(New DesignerVerb("Parse and Save Control...", _
        '            New EventHandler(AddressOf Me.saveControl)))
        '        Return dvc
        '    End Get
        'End Property

        ' Displays a textbox form to receive an HTML 
        ' string that represents a control, and creates
        ' a toolbox item for the control, if not already
        ' present in the selected toolbox category.

        Private Class ParserActionList
            Inherits DesignerActionList

            Private _parent As ControlParserPersisterDesigner
            Private _items As DesignerActionItemCollection

            Public Sub New(ByVal parent As ControlParserPersisterDesigner)
                MyBase.New(parent.Component)
                _parent = parent
            End Sub

            Public Overrides Function GetSortedActionItems() As System.ComponentModel.Design.DesignerActionItemCollection
                If IsNothing(_items) Then
                    _items = New DesignerActionItemCollection()
                    _items.Add(New DesignerActionMethodItem(Me, "saveControl", "Parse and Save Control...", True))
                    _items.Add(New DesignerActionMethodItem(Me, "loadPersistedControl", "Load Persisted Control...", True))
                End If
                Return _items
            End Function

            ' Displays a list of controls in the project, if any,
            ' and displays the HTML markup for the selected control.       
            Private Sub saveControl()
                ' Get the collection of components in the current 
                ' design mode document.
                Dim documentComponents As ComponentCollection = _
                    Me.Component.Site.Container.Components

                ' Filter the components to those that derive from the 
                ' System.Web.UI.Control class.

                ' Create an IComponent array of the maximum possible length needed.
                Dim filterArray(documentComponents.Count) As IComponent

                ' Count the total qualifying components.
                Dim total As Integer = 0
                Dim i As Integer
                For i = 0 To documentComponents.Count - 1
                    ' If the component derives from System.Web.UI.Control, 
                    ' copy a reference to the control to the filterArray 
                    ' array and increment the control count.
                    If GetType(System.Web.UI.Control).IsAssignableFrom(CType(documentComponents(i), Object).GetType()) Then
                        If Not (CType(documentComponents(i), System.Web.UI.Control).UniqueID Is Nothing) Then
                            filterArray(total) = documentComponents(i)
                            total += 1
                        End If
                    End If
                Next i

                If total = 0 Then
                    Throw New Exception( _
                        "Document contains no System.Web.UI.Control components.")
                End If

                ' Move the components that derive from System.Web.UI.Control to a 
                ' new array of the correct size.
                Dim controlArray(total - 1) As System.Web.UI.Control

                For i = 0 To total - 1
                    controlArray(i) = CType(filterArray(i), System.Web.UI.Control)
                Next i

                ' Create a ControlSelectionForm to provide a persistence 
                ' configuration interface.
                Dim selectionForm As New ControlSelectionForm(controlArray)

                ' Display the form.
                If selectionForm.ShowDialog() <> DialogResult.OK Then
                    Return
                End If

                ' Validate the selection.
                If selectionForm.controlList.SelectedIndex = -1 Then
                    Throw New Exception("You must select a control to persist.")
                End If

                ' Parse the selected control.
                Dim persistedData As String = ControlPersister.PersistControl( _
                    controlArray(selectionForm.controlList.SelectedIndex))

                ' Display the control persistence string in a text box.
                Dim displayForm As New StringDisplayForm(persistedData)
                displayForm.ShowDialog()
            End Sub

            ' Displays a textbox form to receive an HTML 
            ' string that represents a control, and creates
            ' a toolbox item for the control, if not already
            ' present in the selected toolbox category.
            Private Sub loadPersistedControl()
                ' Display a StringInputForm to obtain a persisted control string.
                Dim inputForm As New StringInputForm()

                If inputForm.ShowDialog() <> DialogResult.OK Then
                    Return
                End If
                If inputForm.TxBox.Text.Length < 2 Then
                    Return
                End If
                ' Obtain an IDesignerHost for the design-mode document.
                Dim host As IDesignerHost = CType(Me.Component.Site.GetService(GetType(IDesignerHost)), IDesignerHost)

                ' Create a Web control from the persisted control string.
                Dim ctrl As System.Web.UI.Control = ControlParser.ParseControl(host, inputForm.TxBox.Text.Trim())

                ' Create a Web control toolbox item for the type of the control.
                Dim item As New System.Web.UI.Design.WebControlToolboxItem(ctrl.GetType())

                ' Add the Web control toolbox item to the toolbox.
                Dim toolService As IToolboxService = CType(Me.Component.Site.GetService(GetType(IToolboxService)), IToolboxService)
                If Not (toolService Is Nothing) Then
                    toolService.AddToolboxItem(item)
                Else
                    Throw New Exception("IToolboxService was not found.")
                End If
            End Sub
        End Class
    End Class

    ' Simple text display control hosts the ControlParserPersisterDesigner.
    <DesignerAttribute(GetType(ControlParserPersisterDesigner), _
        GetType(IDesigner))> _
    Public Class ControlParserPersisterDesignerControl
        Inherits System.Web.UI.WebControls.WebControl

        Private _text As String

        <Bindable(True), _
            Category("Appearance"), _
            DefaultValue("")> _
        Public Property [Text]() As String
            Get
                Return _text
            End Get
            Set(ByVal Value As String)
                _text = Value
            End Set
        End Property

        Public Sub New()
            [Text] = "Right-click here to access control persistence " & _
                        "methods in design mode"
        End Sub

        Protected Overrides Sub Render(ByVal output As HtmlTextWriter)
            output.Write([Text])
        End Sub
    End Class

    ' Provides a form with a list for selection.
    Friend Class ControlSelectionForm
        Inherits System.Windows.Forms.Form
        Private controlArray() As System.Web.UI.Control
        Public controlList As System.Windows.Forms.ListBox

        Public Sub New(ByVal controlArray() As System.Web.UI.Control)
            Me.controlArray = controlArray

            Me.Size = New Size(400, 500)
            Me.Text = "Control Persister Selection Form"

            Me.SuspendLayout()

            Dim label1 As New System.Windows.Forms.Label()
            label1.Text = "Select the control to persist:"
            label1.Size = New Size(240, 20)
            label1.Location = New Point(10, 10)
            Me.Controls.Add(label1)

            controlList = New System.Windows.Forms.ListBox()
            controlList.Size = New Size(370, 400)
            controlList.Location = New Point(10, 30)
            controlList.Anchor = AnchorStyles.Left Or AnchorStyles.Top _
                    Or AnchorStyles.Bottom Or AnchorStyles.Right
            Me.Controls.Add(controlList)

            Dim okButton As New System.Windows.Forms.Button()
            okButton.Text = "OK"
            okButton.Size = New Size(80, 24)
            okButton.Location = New Point(Me.Width - 100, Me.Height - 60)
            okButton.Anchor = AnchorStyles.Bottom Or AnchorStyles.Right
            okButton.DialogResult = DialogResult.OK
            Me.Controls.Add(okButton)

            Dim cancelButton As New System.Windows.Forms.Button()
            cancelButton.Text = "Cancel"
            cancelButton.Size = New Size(80, 24)
            cancelButton.Location = New Point(Me.Width - 200, Me.Height - 60)
            cancelButton.Anchor = AnchorStyles.Bottom Or AnchorStyles.Right
            cancelButton.DialogResult = DialogResult.Cancel
            Me.Controls.Add(cancelButton)

            Dim i As Integer
            For i = 0 To controlArray.Length - 1
                controlList.Items.Add(controlArray(i).UniqueID)
            Next i
            Me.ResumeLayout()
        End Sub
    End Class

    ' Provides a form with a multiline text box display.
    Friend Class StringDisplayForm
        Inherits System.Windows.Forms.Form

        Private tbox As New System.Windows.Forms.TextBox()

        Public Property TxBox() As System.Windows.Forms.TextBox
            Get
                Return tbox
            End Get
            Set(ByVal value As System.Windows.Forms.TextBox)
                tbox = value
            End Set
        End Property

        Public Sub New(ByVal displayText As String)
            Me.Size = New Size(400, 300)
            Me.Text = "Control Persistence String"

            Me.SuspendLayout()
            Dim tbox As New System.Windows.Forms.TextBox()
            tbox.Multiline = True
            tbox.Size = New Size(Me.Width - 40, Me.Height - 90)
            tbox.Text = displayText
            Me.Controls.Add(tbox)

            Dim okButton As New System.Windows.Forms.Button()
            okButton.Text = "OK"
            okButton.Size = New Size(80, 24)
            okButton.Location = New Point(Me.Width - 100, Me.Height - 60)
            okButton.Anchor = AnchorStyles.Bottom Or AnchorStyles.Right
            okButton.DialogResult = DialogResult.OK
            Me.Controls.Add(okButton)

            Me.ResumeLayout()
        End Sub
    End Class

    ' Provides a form with a multiline text box for input.
    Friend Class StringInputForm
        Inherits System.Windows.Forms.Form
        Private tbox As New System.Windows.Forms.TextBox()

        Public Property TxBox() As System.Windows.Forms.TextBox
            Get
                Return tbox
            End Get
            Set(ByVal value As System.Windows.Forms.TextBox)
                tbox = value
            End Set
        End Property

        Public Sub New()
            Me.Size = New Size(400, 400)
            Me.Text = "Input Control Persistence String"

            Me.SuspendLayout()
            tbox = New System.Windows.Forms.TextBox()
            tbox.Multiline = True
            tbox.Size = New Size(Me.Width - 40, Me.Height - 90)
            tbox.Text = ""
            Me.Controls.Add(tbox)

            Dim okButton As New System.Windows.Forms.Button()
            okButton.Text = "OK"
            okButton.Size = New Size(80, 24)
            okButton.Location = New Point(Me.Width - 100, Me.Height - 60)
            okButton.Anchor = AnchorStyles.Bottom Or AnchorStyles.Right
            okButton.DialogResult = DialogResult.OK
            Me.Controls.Add(okButton)

            Dim cancelButton As New System.Windows.Forms.Button()
            cancelButton.Text = "Cancel"
            cancelButton.Size = New Size(80, 24)
            cancelButton.Location = New Point(Me.Width - 200, Me.Height - 60)
            cancelButton.Anchor = AnchorStyles.Bottom Or AnchorStyles.Right
            cancelButton.DialogResult = DialogResult.Cancel
            Me.Controls.Add(cancelButton)

            Me.ResumeLayout()
        End Sub
    End Class
End Namespace

Remarks

The ControlPersister class provides methods that can persist a Control control or an ITemplate interface implementation as a string of aspx code. The implementation of these methods is driven by metadata attributes, such as the DefaultValueAttribute, PersistenceModeAttribute, and DesignerSerializationVisibilityAttribute.

To create a Control object or an ITemplate interface by parsing a string of control- or template-persistence data, use the ControlParser class methods.

See also

• Control
• ITemplate
• ControlParser