AttributeTable 类
用于定义设计时外观和行为的元数据特性表。
继承层次结构
System.Object
Microsoft.Windows.Design.Metadata.AttributeTable
命名空间: Microsoft.Windows.Design.Metadata
程序集: Microsoft.Windows.Design.Extensibility(在 Microsoft.Windows.Design.Extensibility.dll 中)
语法
声明
Public NotInheritable Class AttributeTable
public sealed class AttributeTable
public ref class AttributeTable sealed
[<Sealed>]
type AttributeTable = class end
public final class AttributeTable
AttributeTable 类型公开以下成员。
属性
名称 | 说明 | |
---|---|---|
AttributedTypes | 获取具有某些形式的特性重写(例如对属性或类型本身的重写)的所有类型的枚举。 |
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方法
名称 | 说明 | |
---|---|---|
ContainsAttributes | 返回一个值,该值指示此表是否包含指定类型的任何元数据。 | |
Equals | 确定指定的 Object 是否等于当前的 Object。 (继承自 Object。) | |
Finalize | 允许对象在“垃圾回收”回收之前尝试释放资源并执行其他清理操作。 (继承自 Object。) | |
GetCustomAttributes(Assembly) | 返回提供给指定的程序集的所有特性的枚举。 | |
GetCustomAttributes(Type) | 返回提供给指定类型的所有特性的枚举。 | |
GetCustomAttributes(Type, String) | 返回提供给指定的类型和成员名称的所有特性的枚举。 | |
GetHashCode | 用作特定类型的哈希函数。 (继承自 Object。) | |
GetType | 获取当前实例的 Type。 (继承自 Object。) | |
MemberwiseClone | 创建当前 Object 的浅表副本。 (继承自 Object。) | |
ToString | 返回表示当前对象的字符串。 (继承自 Object。) |
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备注
使用 AttributeTable 类将设计时元数据特性与 Windows Presentation Foundation (WPF) 类型关联。
若要创建特性表,请调用 AttributeTableBuilder 类的 CreateTable 方法。 有关更多信息,请参见 提供设计时元数据。
特性表实际上是一个只读字典,但其键和值分别进行计算。 如果特性表包含特定类型的特性,则查询该特性表将非常高效。 实际的特性集是按需创建的。
示例
下面的代码示例演示如何创建和填充特性表。 有关更多信息,请参见 演练:创建设计时装饰器。
Imports System
Imports System.Collections
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Reflection
Imports System.Text
Imports System.Windows.Media
Imports System.Windows.Controls
Imports System.Windows
Imports Microsoft.Windows.Design
Imports Microsoft.Windows.Design.Features
Imports 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(GetType(CustomControlLibrary.VisualStudio.Design.Metadata))>
' 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.
Friend Class Metadata
Implements IProvideAttributeTable
' Accessed by the designer to register any design-time metadata.
Public ReadOnly Property AttributeTable() As AttributeTable _
Implements IProvideAttributeTable.AttributeTable
Get
Dim builder As New AttributeTableBuilder()
' Apply the ReadOnlyAttribute to the Background property
' of the Button class.
builder.AddCustomAttributes(GetType(Button), "Background", New ReadOnlyAttribute(True))
Dim attributes As AttributeTable = builder.CreateTable()
Dim hasCustomAttributes As Boolean = attributes.ContainsAttributes(GetType(Button))
Dim types As IEnumerable(Of Type) = attributes.AttributedTypes
' The following code shows how to retrieve custom attributes
' using the GetCustomAttributes method overloads.
Dim attrs0 As IEnumerable = attributes.GetCustomAttributes(GetType(Button))
Dim attrs1 As IEnumerable = attributes.GetCustomAttributes(GetType(Button), "Background")
Return attributes
End Get
End Property
End Class
using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Reflection;
using System.Text;
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();
// Apply the ReadOnlyAttribute to the Background property
// of the Button class.
builder.AddCustomAttributes(
typeof(Button),
"Background",
new ReadOnlyAttribute(true));
AttributeTable attributes = builder.CreateTable();
bool hasCustomAttributes = attributes.ContainsAttributes(typeof(Button));
IEnumerable<Type> types = attributes.AttributedTypes;
// The following code shows how to retrieve custom attributes
// using the GetCustomAttributes method overloads.
IEnumerable attrs0 = attributes.GetCustomAttributes(typeof(Button));
IEnumerable attrs1 = attributes.GetCustomAttributes(
typeof(Button),
"Background");
return attributes;
}
}
}
}
线程安全
此类型的任何公共 static(在 Visual Basic 中为 Shared) 成员都是线程安全的。但不保证所有实例成员都是线程安全的。
请参见
参考
Microsoft.Windows.Design.Metadata 命名空间