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ToolboxItemCreatorCallback (Delegado)

Actualización: noviembre 2007

Proporciona un mecanismo de devolución de llamada que puede crear un ToolboxItem.

Espacio de nombres:  System.Drawing.Design
Ensamblado:  System.Drawing (en System.Drawing.dll)

public delegate ToolboxItem ToolboxItemCreatorCallback(
	Object serializedObject,
	string format
)
/** @delegate */
public delegate ToolboxItem ToolboxItemCreatorCallback(
	Object serializedObject,
	String format
)
JScript no admite delegados.

Parámetros

serializedObject
Tipo: System.Object
Objeto que contiene los datos para los que se va a crear un ToolboxItem.
format
Tipo: System.String

Valor devuelto

Tipo: System.Drawing.Design.ToolboxItem
Objeto ToolboxItem deserializado especificado por serializedObject.

Se puede implementar un método creador de elementos de cuadro de herramientas con una firma de método que coincida con la firma de método de este tipo de delegado que crea un elemento de cuadro de herramientas a partir de cualquier objeto de un formato de datos de Portapapeles concreto ubicado en el cuadro de herramientas. Por ejemplo, es posible diseñar un creador de elementos de cuadro de herramientas que cree un objeto TextBox para almacenar texto pegado en el cuadro de herramientas desde el Portapapeles. Se puede utilizar el método AddCreator de IToolboxService para agregar al cuadro de herramientas un controlador del evento ToolboxItemCreatorCallback de un tipo de datos concreto. El parámetro serializedObject contiene el objeto de los datos.

Cuando se crea un delegado de ToolboxItemCreatorCallback, se identifica el método que controlará el evento. Para asociar el evento al controlador de eventos, se debe agregar una instancia del delegado al evento. Siempre que se produce el evento, se llama al controlador de eventos, a menos que se quite el delegado. Para obtener más información acerca de los delegados de controladores de eventos, vea Eventos y delegados.

En el siguiente ejemplo se proporciona un componente que utiliza IToolboxService para agregar un controlador de formato de datos "Text" o ToolboxItemCreatorCallback al cuadro de herramientas. El delegado de devolución de llamada del creador de datos pasa todos los datos de texto que se hayan pegado al cuadro de herramientas y arrastrado a un formulario a un objeto ToolboxItem personalizado que crea un control TextBox que contiene el texto.

using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Drawing;
using System.Drawing.Design;
using System.Security.Permissions;
using System.Windows.Forms;

namespace TextDataTextBoxComponent
{
    // Component that adds a "Text" data format ToolboxItemCreatorCallback 
    // to the Toolbox. This component uses a custom ToolboxItem that 
    // creates a TextBox containing the text data.
    [PermissionSet(SecurityAction.Demand, Name = "FullTrust")]
    public class TextDataTextBoxComponent : Component
    {
        private bool creatorAdded = false;
        private IToolboxService ts;

        public TextDataTextBoxComponent()
        {                     
        }

        // ISite override to register TextBox creator
        public override System.ComponentModel.ISite Site
        {
            get
            {
                return base.Site;
            }
            set
            {
                if( value != null )
                {                    
                    base.Site = value;

                    if (!creatorAdded)
                    {
                        AddTextTextBoxCreator();
                    }
                }
                else
                {
                    if (creatorAdded)
                    {
                        RemoveTextTextBoxCreator();
                    }

                    base.Site = value;             
                }
            }
        }

        // Adds a "Text" data format creator to the toolbox that creates 
        // a textbox from a text fragment pasted to the toolbox.
        private void AddTextTextBoxCreator()
        {
            ts = (IToolboxService)GetService(typeof(IToolboxService));

            if (ts != null) 
            {
                ToolboxItemCreatorCallback textCreator = 
                    new ToolboxItemCreatorCallback(this.CreateTextBoxForText);

                try
                {
                    ts.AddCreator(
                        textCreator, 
                        "Text", 
                        (IDesignerHost)GetService(typeof(IDesignerHost)));

                    creatorAdded = true;
                }
                catch(Exception ex)
                {
                    MessageBox.Show(
                        ex.ToString(), 
                        "Exception Information");
                }                
            }
        }

        // Removes any "Text" data format creator from the toolbox.
        private void RemoveTextTextBoxCreator()
        {
            if (ts != null)             
            {
                ts.RemoveCreator(
                    "Text", 
                    (IDesignerHost)GetService(typeof(IDesignerHost)));            

                creatorAdded = false;
            }
        }

        // ToolboxItemCreatorCallback delegate format method to create 
        // the toolbox item.
        private ToolboxItem CreateTextBoxForText(
            object serializedObject, 
            string format)
        {
            DataObject o = new DataObject((IDataObject)serializedObject);

            string[] formats = o.GetFormats();

            if (o.GetDataPresent("System.String", true))
            {
                string toolboxText = (string)(o.GetData("System.String", true));
                return (new TextToolboxItem(toolboxText));
            }

            return null;
        }

        protected override void Dispose(bool disposing)
        {
            if (creatorAdded)
            {
                RemoveTextTextBoxCreator();
            }
        }        
    }

    // Custom toolbox item creates a TextBox and sets its Text property
    // to the constructor-specified text.
    [PermissionSet(SecurityAction.Demand, Name = "FullTrust")] 
    public class TextToolboxItem : ToolboxItem
    {
        private string text;
        private delegate void SetTextMethodHandler(Control c, string text);

        public TextToolboxItem(string text) : base()
        {
            this.text = text;
        }

        // ToolboxItem.CreateComponentsCore override to create the TextBox 
        // and link a method to set its Text property.
        [PermissionSet(SecurityAction.Demand, Name="FullTrust")] 
        protected override IComponent[] CreateComponentsCore(IDesignerHost host)
        {
            System.Windows.Forms.TextBox textbox = 
                (TextBox)host.CreateComponent(typeof(TextBox));

            // Because the designer resets the text of the textbox, use 
            // a SetTextMethodHandler to set the text to the value of 
            // the text data.
            Control c = host.RootComponent as Control;
            c.BeginInvoke(
                new SetTextMethodHandler(OnSetText), 
                new object[] {textbox, text});

            return new System.ComponentModel.IComponent[] { textbox };
        }        

        // Method to set the text property of a TextBox after it is initialized.
        private void OnSetText(Control c, string text) 
        {
            c.Text = text;
        }
    }
}


package TextDataTextBoxComponent;

import System.*;
import System.ComponentModel.*;
import System.ComponentModel.Design.*;
import System.Drawing.*;
import System.Drawing.Design.*;
import System.Windows.Forms.*;
// Component that adds a "Text" data format ToolboxItemCreatorCallback 
// to the Toolbox that creates a custom ToolboxItem that 
// creates a TextBox containing the text data.
public class TextDataTextBoxComponent extends System.ComponentModel.Component
{
    private boolean creatorAdded = false;
    private IToolboxService ts;

    public TextDataTextBoxComponent()
    {
    } 

    // ISite override to register TextBox creator
    /** @property 
     */
    public System.ComponentModel.ISite get_Site()
    {
        return super.get_Site();
    } 

    /** @property 
     */
    public void set_Site(System.ComponentModel.ISite value)
    {
        if (value != null) {
            super.set_Site(value);
            if (!(creatorAdded)) {
                AddTextTextBoxCreator();
            }
        }
        else {
            if (creatorAdded) {
                RemoveTextTextBoxCreator();
            }
            super.set_Site(value);
        }
    } 

    // Adds a "Text" data format creator to the toolbox that creates 
    // a textbox from a text fragment pasted to the toolbox.
    private void AddTextTextBoxCreator()
    {
        ts = (IToolboxService)GetService(IToolboxService.class.ToType());
        if (ts != null) {
            ToolboxItemCreatorCallback textCreator =
                new ToolboxItemCreatorCallback(this.CreateTextBoxForText);
            try {
                ts.AddCreator(textCreator, "Text",
                    (IDesignerHost)GetService(IDesignerHost.class.ToType()));
                creatorAdded = true;
            }
            catch (System.Exception ex) {
                MessageBox.Show(ex.ToString(), "Exception Information");
            }
        }
    } 

    // Removes any "Text" data format creator from the toolbox.
    private void RemoveTextTextBoxCreator()
    {
        if (ts != null) {
            ts.RemoveCreator("Text",
                (IDesignerHost)GetService(IDesignerHost.class.ToType()));
            creatorAdded = false;
        }
    } 

    // ToolboxItemCreatorCallback delegate format method to create 
    // the toolbox item.
    private ToolboxItem CreateTextBoxForText(Object serializedObject,
        String format)
    {
		DataObject o = new DataObject((IDataObject)serializedObject);

		if (o.GetDataPresent("System.String", true))
		{
			String toolboxText = (String)(o.GetData("System.String", true));
			return (new TextToolboxItem(toolboxText));
		}

        return null;
    } 

    protected void Dispose(boolean disposing)
    {
        if (creatorAdded) {
            RemoveTextTextBoxCreator();
        }
    } 
} 

// Custom toolbox item creates a TextBox and sets its Text property
// to the constructor-specified text.
public class TextToolboxItem extends System.Drawing.Design.ToolboxItem
{
    private String text;

    /** @delegate 
     */
    private delegate void SetTextMethodHandler(Control c, String text);

    /** @attribute System.Security.Permissions.PermissionSet(
        System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")
     */
    public TextToolboxItem(String text)
    {
        this.text = text;
    } 

    // ToolboxItem.CreateComponentsCore override to create the TextBox 
    // and link a method to set its Text property.
    /** @attribute System.Security.Permissions.PermissionSet(
        System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")
     */
    protected System.ComponentModel.IComponent[] CreateComponentsCore(
        System.ComponentModel.Design.IDesignerHost host)
    {
        System.Windows.Forms.TextBox textbox =
            (TextBox)host.CreateComponent(TextBox.class.ToType());

        // Because the designer resets the text of the textbox, use 
        // a SetTextMethodHandler to set the text to the value of 
        // the text data.
        Control c = (Control)host.get_RootComponent();
        c.BeginInvoke(new SetTextMethodHandler(OnSetText),
            new Object[] { textbox, text });

        return new System.ComponentModel.IComponent[] { textbox };
    } 

    // Method to set the text property of a TextBox after it is initialized.
    private void OnSetText(Control c, String text)
    {
        c.set_Text(text);
    } 
} 


Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

.NET Framework y .NET Compact Framework no admiten todas las versiones de cada plataforma. Para obtener una lista de las versiones compatibles, vea Requisitos de sistema de .NET Framework.

.NET Framework

Compatible con: 3.5, 3.0, 2.0, 1.1, 1.0
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