AttributeCallback 委派

發行項
08/12/2011

會在型別需要屬性時呼叫。

命名空間： Microsoft.Windows.Design.Metadata
組件： Microsoft.Windows.Design.Extensibility (在 Microsoft.Windows.Design.Extensibility.dll 中)

語法

'宣告
Public Delegate Sub AttributeCallback ( _
    builder As AttributeCallbackBuilder _
)

public delegate void AttributeCallback(
    AttributeCallbackBuilder builder
)

public delegate void AttributeCallback(
    AttributeCallbackBuilder^ builder
)

type AttributeCallback = 
    delegate of 
        builder:AttributeCallbackBuilder -> unit

JScript 不支援委派。

參數

builder
型別：Microsoft.Windows.Design.Metadata.AttributeCallbackBuilder
可用來加入屬性的 AttributeCallbackBuilder。AttributeCallbackBuilder 委派僅能針對要求中繼資料的型別建置屬性。

備註

當您在要大型屬性表格中填入內容時，請使用 AttributeCallback 委派。使用回呼模式可以延後屬性表格的填入作業，直到設計工具需要型別的設計階段中繼資料為止。

範例

在下列程式碼範例中，會說明如何使用 AttributeCallbackBuilder 類別建立屬性表格，並在其中填入內容。

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.ComponentModel;
using System.Reflection;
using System.Windows.Media;
using System.Windows.Controls;
using System.Windows;

using Microsoft.Windows.Design.Features;
using Microsoft.Windows.Design.Metadata;

// The ProvideMetadata assembly-level attribute indicates to designers
// that this assembly contains a class that provides an attribute table. 
[assembly: ProvideMetadata(typeof(CustomControlLibrary.VisualStudio.Design.Metadata))]

namespace CustomControlLibrary.VisualStudio.Design
{
    // Container for any general design-time metadata to initialize.
    // Designers look for a type in the design-time assembly that 
    // implements IProvideAttributeTable. If found, designers instantiate 
    // this class and access its AttributeTable property automatically.
    internal class Metadata : IProvideAttributeTable
    {
        // Accessed by the designer to register any design-time metadata.
        public AttributeTable AttributeTable
        {
            get
            {
                AttributeTableBuilder builder = new AttributeTableBuilder();

                // Build the attribute table by using the AttributeCallbackBuilder 
                // class. The attribute table is not populated until the designer
                // needs it, which is more efficient for large attribute tables.
                builder.AddCallback(
                    typeof(Button),
                    delegate(AttributeCallbackBuilder callbackBuilder)
                    {
                        callbackBuilder.AddCustomAttributes(
                            new DefaultPropertyAttribute("Content"));

                        // Apply the ReadOnlyAttribute to the Background property 
                        // of the Button class.
                        callbackBuilder.AddCustomAttributes(
                            "Background",
                            new ReadOnlyAttribute(true));
                    });

                return builder.CreateTable();
            }
        }
    }
}