MenuDesigner 类

定义

public ref class MenuDesigner : System::Web::UI::Design::WebControls::HierarchicalDataBoundControlDesigner, System::Web::UI::Design::IDataBindingSchemaProvider

public class MenuDesigner : System.Web.UI.Design.WebControls.HierarchicalDataBoundControlDesigner, System.Web.UI.Design.IDataBindingSchemaProvider

type MenuDesigner = class
    inherit HierarchicalDataBoundControlDesigner
    interface IDataBindingSchemaProvider

Public Class MenuDesigner
Inherits HierarchicalDataBoundControlDesigner
Implements IDataBindingSchemaProvider

继承

Object

ComponentDesigner

HtmlControlDesigner

ControlDesigner

BaseDataBoundControlDesigner

HierarchicalDataBoundControlDesigner

MenuDesigner

实现

IDataBindingSchemaProvider

示例

下面的代码示例演示如何扩展 MenuDesigner 类，以在设计时更改派生自 控件的 Menu 控件的外观。

该示例从 Menu派生MyMenu类。 类 MyMenu 是 的副本 Menu。 该示例还从 类派生MyMenuDesigner类，然后对 类应用 DesignerAttribute 特性MyMenuDesignerMyMenu。MenuDesigner

The MyMenuDesigner 重写以下 MenuDesigner 成员：

• 在 GetDesignTimeHtml 控件周围绘制橙色虚线边框以使其范围更可见的方法。

• 为 GetErrorDesignTimeHtml 包含错误消息的占位符生成标记的方法，该占位符以红色粗体文本呈现。

• 为 GetEmptyDesignTimeHtml 包含指示未定义菜单项的消息的占位符生成标记的 。

• Initialize如果关联的控件不是 MyMenu 对象，则引发ArgumentException异常的方法。

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

namespace Examples.CS.WebControls.Design
{
    // The MyMenu is a copy of the Menu.
    [AspNetHostingPermission(SecurityAction.Demand, 
        Level = AspNetHostingPermissionLevel.Minimal)]
    [AspNetHostingPermission(SecurityAction.InheritanceDemand, 
        Level = AspNetHostingPermissionLevel.Minimal)]
    [Designer(typeof(Examples.CS.WebControls.Design.MyMenuDesigner))]
    public class MyMenu : Menu
    {
    } // MyMenu

    // Override members of the MenuDesigner.
    public class MyMenuDesigner : MenuDesigner
    {
        // Generate the design-time markup for the control when an error occurs.
        protected override string GetErrorDesignTimeHtml(Exception ex) 
        {
            // Write the error message text in red, bold.
            string errorRendering =
                "<span style=\"font-weight:bold; color:Red; \">" +
                ex.Message + "</span>";

            return CreatePlaceHolderDesignTimeHtml(errorRendering);
        } // GetErrorDesignTimeHtml

        // Generate the design-time markup for the control 
        // when the template is empty.
        protected override string GetEmptyDesignTimeHtml()
        {
            string noElements = "Contains no menu items.";

            return CreatePlaceHolderDesignTimeHtml(noElements);
        } // GetEmptyDesignTimeHtml

        // Generate the design-time markup.
        public override string GetDesignTimeHtml()
        {
            // Make the control more visible in the designer.  If the border 
            // style is None or NotSet, change the border to an orange dotted line. 
            MyMenu myMenuCtl = (MyMenu)ViewControl;
            string markup = null;

            // Check if the border style should be changed.
            if (myMenuCtl.BorderStyle == BorderStyle.NotSet ||
                myMenuCtl.BorderStyle == BorderStyle.None)
            {
                BorderStyle oldBorderStyle = myMenuCtl.BorderStyle;
                Color oldBorderColor = myMenuCtl.BorderColor;

                // Set the design-time properties and catch any exceptions.
                try
                {
                    myMenuCtl.BorderStyle = BorderStyle.Dotted;
                    myMenuCtl.BorderColor = Color.FromArgb(0xFF7F00);

                    // Call the base method to generate the markup.
                    markup = base.GetDesignTimeHtml();
                }
                catch (Exception ex)
                {
                    markup = GetErrorDesignTimeHtml(ex);
                }
                finally
                {
                    // Restore the properties to their original settings.
                    myMenuCtl.BorderStyle = oldBorderStyle;
                    myMenuCtl.BorderColor = oldBorderColor;
                }
            }
            else
            {
                // Call the base method to generate the markup.
                markup = base.GetDesignTimeHtml();
            }

            return markup;
        } // GetDesignTimeHtml

        public override void Initialize(IComponent component)
        {
            // Ensure that only a MyMenu can be created in this designer.
            if (!(component is MyMenu))
                throw new ArgumentException(
                    "The component is not a MyMenu control.");
            
            base.Initialize(component);
        } // Initialize
    } // MyMenuDesigner
} // Examples.CS.WebControls.Design

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

Namespace Examples.VB.WebControls.Design

    ' The MyMenu is a copy of the Menu.
    <AspNetHostingPermission(SecurityAction.Demand, _
        Level:=AspNetHostingPermissionLevel.Minimal)> _
    <AspNetHostingPermission(SecurityAction.InheritanceDemand, _
        Level:=AspNetHostingPermissionLevel.Minimal)> _
    <Designer(GetType(Examples.VB.WebControls.Design.MyMenuDesigner))> _
    Public Class MyMenu
        Inherits Menu
    End Class

    ' Override members of the MenuDesigner.
    Public Class MyMenuDesigner
        Inherits MenuDesigner

        ' Generate the design-time markup for the control when an error occurs.
        Protected Overrides Function GetErrorDesignTimeHtml( _
            ByVal ex As Exception) As String

            ' Write the error message text in red, bold.
            Dim errorRendering As String = _
                "<span style=""font-weight:bold; color:Red; "">" & _
                ex.Message & "</span>"

            Return CreatePlaceHolderDesignTimeHtml(errorRendering)

        End Function ' GetErrorDesignTimeHtml

        ' Generate the design-time markup for the control 
        ' when the template is empty.
        Protected Overrides Function GetEmptyDesignTimeHtml() As String

            Dim noElements As String = "Contains no menu items."

            Return CreatePlaceHolderDesignTimeHtml(noElements)

        End Function ' GetEmptyDesignTimeHtml

        ' Generate the design-time markup.
        Public Overrides Function GetDesignTimeHtml() As String

            ' Make the control more visible in the designer.  If the border 
            ' style is None or NotSet, change the border to an orange dotted line. 
            Dim myMenuCtl As MyMenu = CType(ViewControl, MyMenu)
            Dim markup As String = Nothing

            ' Check if the border style should be changed.
            If (myMenuCtl.BorderStyle = BorderStyle.NotSet Or _
                myMenuCtl.BorderStyle = BorderStyle.None) Then

                Dim oldBorderStyle As BorderStyle = myMenuCtl.BorderStyle
                Dim oldBorderColor As Color = myMenuCtl.BorderColor

                ' Set the design-time properties and catch any exceptions.
                Try
                    myMenuCtl.BorderStyle = BorderStyle.Dotted
                    myMenuCtl.BorderColor = Color.FromArgb(&HFF7F00)

                    ' Call the base method to generate the markup.
                    markup = MyBase.GetDesignTimeHtml()

                Catch ex As Exception
                    markup = GetErrorDesignTimeHtml(ex)

                Finally
                    ' Restore the properties to their original settings.
                    myMenuCtl.BorderStyle = oldBorderStyle
                    myMenuCtl.BorderColor = oldBorderColor
                End Try

            Else
                ' Call the base method to generate the markup.
                markup = MyBase.GetDesignTimeHtml()
            End If

            Return markup

        End Function ' GetDesignTimeHtml

        Public Overrides Sub Initialize(ByVal component As IComponent)

            ' Ensure that only a MyMenu can be created in this designer. 
            If Not TypeOf component Is MyMenu Then
                Throw New ArgumentException( _
                    "The component is not a MyMenu control.")
            End If

            MyBase.Initialize(component)

        End Sub
    End Class
End Namespace ' Examples.VB.WebControls.Design

注解

类 Menu 提供分层菜单 Web 服务器控件。

在可视化设计器中，从“源”视图切换到“设计”视图时，将分析描述关联 Menu 控件的标记源代码，并在设计图面上创建控件的设计时版本。 切换回“源”视图时，设计时控件将保留到标记中，并添加到网页的现有标记中。 类 MenuDesigner 为 Menu 可视化设计器中的控件提供设计时支持。

属性 ActionLists 返回 一个 DesignerActionListCollection 对象，该对象通常包含从 DesignerActionList 设计器继承树中每个级别的 类派生的对象。 属性 AutoFormats 返回用于在“ 自动格式 ”对话框中显示的格式设置方案的集合。

属性 TemplateGroups 返回关联 Menu 控件的模板的模板组的集合。 属性 UsePreviewControl 始终返回 true，指示设计器创建关联的 Menu 的临时副本以生成设计时标记。

类 MenuDesigner 方法提供以下功能：

• 方法 Initialize 使设计器准备好查看、编辑和设计关联的 Menu 控件。 方法 GetDesignTimeHtml 返回用于在设计时呈现关联的 Menu 的标记。

• 方法 GetEmptyDesignTimeHtml 获取标记，该标记在设计时呈现关联控件的占位符时，如果没有其他可用标记。 方法 GetErrorDesignTimeHtml 提供标记，该标记在发生错误时在设计时呈现关联的控件。

• 方法 DataBind 将关联的 Menu 控件绑定到设计时数据源。 方法 GetSampleDataSource 构造可在设计时用于关联控件的示例数据源。

构造函数

属性

方法

显式接口实现

适用于

另请参阅

• Menu
• HierarchicalDataBoundControl
• HierarchicalDataBoundControlDesigner
• BaseDataBoundControlDesigner
• ControlDesigner
• HtmlControlDesigner
• ComponentDesigner
• ASP.NET 控件设计器简介
• 演练：为 Web 服务器控件创建基本控件设计器