WebPartDesigner 类

定义

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

继承

Object

ComponentDesigner

HtmlControlDesigner

ControlDesigner

CompositeControlDesigner

PartDesigner

WebPartDesigner

示例

下面的代码示例演示控件与其关联的 WebPartDesigner之间的WebPart交互。 控件 WebPart 包含一个 Calendar 控件，最终用户从中选择其生日，一个 Button 用于提交选择的控件，以及一个 Label 用于显示用户生日消息的控件。 验证 WebPartDesigner 关联的控件是否为预期类型，然后自定义该控件的设计时呈现。 请注意，设计器的可视自定义项仅在设计时可见，而关联控件的自定义项在运行时和设计时都可见。

此示例中重写的所有方法都派生自 ControlDesigner 基类。 有关其他可用成员及其用法，请参阅 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

注解

类 WebPartDesigner 在设计时为 WebPart 控件提供可视表示形式。 它派生自 类， PartDesigner 并添加验证以验证关联的控件是 WebPart 控件或派生类型。

WebPartDesignerUsePreviewControl从其父级继承属性，该属性始终设置为 true。 这会导致可视化设计环境生成一个 View 控件，以在设计图面上保存 的 WebPart 临时副本;然后，此副本将持久保存到标记中。 如果重写 UsePreviewControl 属性以返回 false，则视觉设计环境会直接从实际 WebPart 控件生成标记。

Web 部件设计器通常与常规控件设计器非常类似;设置设计时外观的主要方法派生自 ControlDesigner 类。 具体而言，可以重写 方法以 GetDesignTimeHtml 更改与 控件关联的设计时标记。 同样，可以重写 GetErrorDesignTimeHtml 和 GetEmptyDesignTimeHtml 方法，分别处理错误和空字符串 (“”) 。

构造函数

属性

方法

显式接口实现

适用于

另请参阅

• ControlDesigner
• ASP.NET Web 部件控件
• ASP.NET 控件设计器概述