WebPartDesigner Klass

Definition

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

Arv

Object

ComponentDesigner

HtmlControlDesigner

ControlDesigner

CompositeControlDesigner

PartDesigner

WebPartDesigner

Exempel

I följande kodexempel visas interaktionen mellan en WebPart kontroll och dess associerade WebPartDesigner. Kontrollen WebPart innehåller en Calendar kontroll från vilken slutanvändaren väljer sin födelsedag, en Button kontroll för att skicka markeringen och en Label kontroll för att visa ett meddelande på användarens födelsedag. Verifierar WebPartDesigner att den associerade kontrollen är av den förväntade typen och anpassar sedan designtidsåtergivningen av den nämnda kontrollen. Observera att de visuella anpassningarna av designern endast visas vid designtillfället, medan de för den associerade kontrollen visas både vid körning och design.

Alla metoder som åsidosättas i det här exemplet härleds från basklassen ControlDesigner . Andra tillgängliga medlemmar och deras användning finns i 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

Kommentarer

Klassen WebPartDesigner tillhandahåller den visuella representationen för WebPart kontroller vid designtillfället. Den härleds från PartDesigner klassen och lägger till validering för att verifiera att den associerade kontrollen är en WebPart kontroll eller härledd typ.

WebPartDesigner ärver en UsePreviewControl egenskap från dess överordnade som alltid är inställd på true. Detta gör att den visuella designmiljön genererar en View kontroll för att lagra en tillfällig kopia av WebPart på designytan. Kopian sparas sedan i markering. Om du åsidosätter UsePreviewControl egenskapen för att returnera falsegenererar den visuella designmiljön markering direkt från den faktiska WebPart kontrollen.

Webbdelar designers fungerar vanligtvis ungefär som vanliga kontrolldesigners; huvudmetoderna för att ange designtidsutseende härleds från ControlDesigner klassen. Mer specifikt kan du åsidosätta GetDesignTimeHtml metoden för att ändra den designtidsmarkering som är associerad med kontrollen. Du kan också åsidosätta GetErrorDesignTimeHtml metoderna och GetEmptyDesignTimeHtml för att hantera fel respektive tomma strängar (").

Se även

• ControlDesigner
• ASP.NET webbdelskontroller
• översikt över ASP.NET Control Designers