WebPartDesigner Clase

Definición

public ref class WebPartDesigner : System::Web::UI::Design::WebControls::WebParts::PartDesigner

public class WebPartDesigner : System.Web.UI.Design.WebControls.WebParts.PartDesigner

type WebPartDesigner = class
    inherit PartDesigner

Public Class WebPartDesigner
Inherits PartDesigner

Herencia

Object

ComponentDesigner

HtmlControlDesigner

ControlDesigner

CompositeControlDesigner

PartDesigner

WebPartDesigner

Ejemplos

En el ejemplo de código siguiente se muestra la interacción entre un WebPart control y su asociado WebPartDesigner. El WebPart control contiene un Calendar control del que el usuario final selecciona su cumpleaños, un Button control para enviar la selección y un Label control para mostrar un mensaje en el cumpleaños del usuario. WebPartDesigner Comprueba que el control asociado es del tipo esperado y, a continuación, personaliza la representación en tiempo de diseño de dicho control. Tenga en cuenta que las personalizaciones visuales del diseñador solo son visibles en tiempo de diseño, mientras que las del control asociado son visibles tanto en tiempo de ejecución como en tiempo de diseño.

Todos los métodos invalidados en este ejemplo derivan de la ControlDesigner clase base. Para otros miembros disponibles y su uso, vea System.Web.UI.Design.ControlDesigner.

using System;
using System.Security.Permissions;
using System.Web;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.Design.WebControls.WebParts;
using System.ComponentModel;

/// <summary>
/// BirthdayPart demonstrates some of the most
/// common overrides of members of the WebPart
/// class. BirthdayPartDesigner shows how to 
/// customize the rendering of a custom WebPart
/// control.
/// </summary>
namespace Samples.AspNet.CS.Controls
{
  [AspNetHostingPermission(SecurityAction.Demand, 
    Level=AspNetHostingPermissionLevel.Minimal)]
  [AspNetHostingPermission(SecurityAction.InheritanceDemand, 
    Level=AspNetHostingPermissionLevel.Minimal)]
  [Designer(typeof(BirthdayPartDesigner))]
  public class BirthdayPart : WebPart
  {
    private DateTime birthDate;
    Calendar input;
    Label displayContent;

    public BirthdayPart()
    {
      this.AllowClose = false;
      this.Title = "Enter your birthday";
    }

    [
      Personalizable(PersonalizationScope.User, true),
      WebBrowsable()
    ]
    public DateTime BirthDate
    {
      get { return birthDate; }
      set { birthDate = value; }
    }
    
    // Set the appearance of the control at run time.
    protected override void CreateChildControls()
    {
      Controls.Clear();
      input = new Calendar();
      this.Controls.Add(input);
      Button update = new Button();
      update.Text = "Submit";
      update.Click += new EventHandler(this.submit_Click);
      this.Controls.Add(update);
      displayContent = new Label();
      displayContent.BackColor = 
      System.Drawing.Color.LightBlue;
      Literal br = new Literal();
      br.Text = "<br />";
      if ((this.birthDate.Day == DateTime.Now.Day)
        && (this.birthDate.Month == DateTime.Now.Month))
      {
        displayContent.Text = "Happy Birthday!";
        this.Controls.Add(br);
        this.Controls.Add(displayContent);
      }
    }

    private void submit_Click(object sender, EventArgs e)
    {
      this.birthDate = input.SelectedDate;
    }
  }

  public class BirthdayPartDesigner : WebPartDesigner
  {
    public override void Initialize(IComponent component)
    {
      // Verify that the associated control is a BirthdayPart.
      if (!typeof(BirthdayPart).IsInstanceOfType(component))
      {
        throw new ArgumentException("The specified control is not of type 'BirthdayPart'", "component");
      }
      base.Initialize(component);
    }

    // Here is where you make customizations
    // to design time appearance that will not
    // be visible to the end user.
    public override string GetDesignTimeHtml()
    {
      string designTimeHtml = null;
      try
      {
        designTimeHtml = base.GetDesignTimeHtml();
        string s = "<hr /><hr />I just added these lines to the"
          + " bottom of the control.<hr /><hr /></div>";
        designTimeHtml = designTimeHtml.Replace("</div>", s);
      }
      catch (Exception ex)
      {
        designTimeHtml = GetErrorDesignTimeHtml(ex);
      }
      finally
      {
        // undo any changes in the try block
      }

      if ((designTimeHtml == null) || (designTimeHtml.Length == 0))
      {
        designTimeHtml = GetEmptyDesignTimeHtml();
      }
      return designTimeHtml;
    }

    // This method normally returns a blank string.
    // Override to return a meaningful message.
    protected override string GetEmptyDesignTimeHtml()
    {
      return CreatePlaceHolderDesignTimeHtml(
        "<hr />If the page developer forgot to fill in a " +
        "required property you could tell them here.<hr />");
    }
    
    // Add specific text to the generic error message.
    protected override string GetErrorDesignTimeHtml(Exception e)
    {
      string s = "<hr />The control failed to render.";
      return(s + e.Message + "<hr />");
    }
  }
}

Imports System.Security.Permissions
Imports System.Web
Imports System.Web.UI.WebControls
Imports System.Web.UI.WebControls.WebParts
Imports System.Web.UI.Design.WebControls.WebParts
Imports System.ComponentModel

' BirthdayPart demonstrates some of the most
' common overrides of members of the WebPart
' class. BirthdayPartDesigner shows how to 
' customize the rendering of a custom WebPart
' control.
Namespace Samples.AspNet.VB.Controls
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    <AspNetHostingPermission(SecurityAction.InheritanceDemand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    <Designer(GetType(BirthdayPartDesigner))> _
    Public Class BirthdayPart
        Inherits WebPart
        Private m_birthDate As DateTime
        Private input As Calendar
        Private displayContent As Label

        Public Sub New()
            Me.AllowClose = False
            Me.Title = "Enter your birthday"
        End Sub

        <Personalizable(PersonalizationScope.User, True), WebBrowsable()> _
        Public Property BirthDate() As DateTime
            Get
                Return m_birthDate
            End Get
            Set(value As DateTime)
                m_birthDate = value
            End Set
        End Property

        ' Set the appearance of the control at run time.
        Protected Overrides Sub CreateChildControls()
            Controls.Clear()
            input = New Calendar()
            Me.Controls.Add(input)
            Dim update As New Button()
            update.Text = "Submit"
            AddHandler update.Click, New EventHandler(AddressOf Me.submit_Click)
            Me.Controls.Add(update)
            displayContent = New Label()
            displayContent.BackColor = System.Drawing.Color.LightBlue
            Dim br As New Literal()
            br.Text = "<br />"
            If (Me.m_birthDate.Day = DateTime.Now.Day) AndAlso (Me.m_birthDate.Month = DateTime.Now.Month) Then
                displayContent.Text = "Happy Birthday!"
                Me.Controls.Add(br)
                Me.Controls.Add(displayContent)
            End If
        End Sub

        Private Sub submit_Click(sender As Object, e As EventArgs)
            Me.m_birthDate = input.SelectedDate
        End Sub
    End Class

    Public Class BirthdayPartDesigner
        Inherits WebPartDesigner
        Public Overrides Sub Initialize(component As IComponent)
            ' Verify that the associated control is a BirthdayPart.
            If Not GetType(BirthdayPart).IsInstanceOfType(component) Then
                Throw New ArgumentException("The specified control is not of type 'BirthdayPart'", "component")
            End If
            MyBase.Initialize(component)
        End Sub

        ' Here is where you make customizations
        ' to design time appearance that will not
        ' be visible to the end user.
        Public Overrides Function GetDesignTimeHtml() As String
            Dim designTimeHtml As String = Nothing
            Try
                designTimeHtml = MyBase.GetDesignTimeHtml()
                Dim s As String = "<hr /><hr />I just added these lines to the" & " bottom of the control.<hr /><hr /></div>"
                designTimeHtml = designTimeHtml.Replace("</div>", s)
            Catch ex As Exception
                designTimeHtml = GetErrorDesignTimeHtml(ex)
                ' undo any changes in the try block
            Finally
            End Try

            If (designTimeHtml Is Nothing) OrElse (designTimeHtml.Length = 0) Then
                designTimeHtml = GetEmptyDesignTimeHtml()
            End If
            Return designTimeHtml
        End Function

        ' This method normally returns a blank string.
        ' Override to return a meaningful message.
        Protected Overrides Function GetEmptyDesignTimeHtml() As String
            Return CreatePlaceHolderDesignTimeHtml("<hr />If the page developer forgot to fill in a " & "required property you could tell them here.<hr />")
        End Function

        ' Add specific text to the generic error message.
        Protected Overrides Function GetErrorDesignTimeHtml(e As Exception) As String
            Dim s As String = "<hr />The control failed to render."
            Return (s & e.Message & "<hr />")
        End Function
    End Class
End Namespace

Comentarios

La WebPartDesigner clase proporciona la representación visual de WebPart los controles en tiempo de diseño. Se deriva de la PartDesigner clase y agrega validación para comprobar que el control asociado es un control o un WebPart tipo derivado.

WebPartDesigner hereda una UsePreviewControl propiedad de su elemento primario que siempre se establece trueen . Esto hace que el entorno de diseño visual genere un View control que contenga una copia temporal de en WebPart la superficie de diseño; esta copia se conserva en el marcado. Si invalida la UsePreviewControl propiedad para devolver false, el entorno de diseño visual genera marcado directamente desde el control real WebPart .

Los diseñadores de elementos web suelen actuar de forma muy similar a los diseñadores de controles normales; Los métodos principales para establecer la apariencia en tiempo de diseño derivan de la ControlDesigner clase . En concreto, puede invalidar el GetDesignTimeHtml método para cambiar el marcado en tiempo de diseño asociado al control . Del mismo modo, puede invalidar los GetErrorDesignTimeHtml métodos y GetEmptyDesignTimeHtml para controlar errores y cadenas vacías (""), respectivamente.

Constructores

Propiedades

Métodos

Implementaciones de interfaz explícitas

Se aplica a

Consulte también

• ControlDesigner
• controles de elementos web de ASP.NET
• Introducción a los diseñadores de controles de ASP.NET