ContentPropertyAttribute 类

定义

指示某种类型的哪个属性是 XAML 内容属性。Indicates which property of a type is the XAML content property. 处理特性化类型的 XAML 表示形式的 XAML 子元素时,XAML 处理器会使用此信息。A XAML processor uses this information when processing XAML child elements of XAML representations of the attributed type.

public ref class ContentPropertyAttribute sealed : Attribute
[System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=false, Inherited=true)]
public sealed class ContentPropertyAttribute : Attribute
type ContentPropertyAttribute = class
    inherit Attribute
Public NotInheritable Class ContentPropertyAttribute
Inherits Attribute
继承
ContentPropertyAttribute
属性

示例

下面的示例创建一个名为 Film 的类,该类应用了 ContentPropertyAttributeThe following example creates a class named Film that has a ContentPropertyAttribute applied. 名为 Title 的属性表示为 content 属性。The property named Title is indicated as the content property.

[ContentProperty("Title")]
public class Film
{
    public Film()
    {
    }

    public string Title
    {
        get { return _title; }
        set { _title = value; }
    }

    private string _title;
}
<ContentProperty("Title")>
Public Class Film
    Public Sub New()
    End Sub

    Public Property Title() As String
        Get
            Return _title
        End Get
        Set(ByVal value As String)
            _title = value
        End Set
    End Property

    Private _title As String
End Class

注解

如果 ContentPropertyAttribute 的关联属性的类型不是 stringobject,则 XAML 处理器会尝试标识值转换方法。If the associated property of a ContentPropertyAttribute is not of type string or object, a XAML processor attempts to identify a value conversion technique. 第一次检查是对 XAML 语言基元或特定 XAML 编写器实现启用的特定本机转换的本机类型转换。The first check is for native type conversion, either of the XAML language primitives or of specific native conversions enabled by that particular XAML writer implementation. 下一步是查找类型转换器。The next step is to look for a type converter. 在 .NET 实现中,根据应用的成员级别或类型级别定义上的 TypeConverterAttribute 标识类型转换器。In the .NET implementations, a type converter is identified based on TypeConverterAttribute on either the member level or type level definition that applies. 如果无法标识值转换,XAML 对象编写器通常会引发异常。If no value conversion can be identified, a XAML object writer typically throws an exception.

为了接受多个对象元素作为内容,必须将 XAML 内容属性的类型作为集合类型来支持。In order to accept more than a single object element as content, the type of the XAML content property must be supportable as a collection type.

由于属性的 Inherited=true 声明,因此 ContentPropertyAttribute 的值通常也将内容属性指定应用于所有派生的类。Because of the Inherited=true declaration of the attribute, a value for a ContentPropertyAttribute normally applies a content property designation to all derived classes as well. 通过应用空 ContentPropertyAttribute,派生类可以通过基类删除内容属性特性的声明(并注意,该类没有内容属性)。Applying an empty ContentPropertyAttribute enables a derived class to remove a declaration of a content property attribute by a base class (and to note that the class has no content property). 应用不同的命名 ContentPropertyAttribute 会将继承的 ContentPropertyAttribute 替换为新的。Applying a differently named ContentPropertyAttribute replaces the inherited ContentPropertyAttribute with the new one.

在 .NET Framework 的以前版本中,此类存在于 WPF 特定的程序集 WindowsBase 中,并且在 Windows Communication Foundation (WCF)中也有并行实现。In previous versions of the .NET Framework, this class existed in the WPF-specific assembly WindowsBase, and also had a parallel implementation in Windows Communication Foundation (WCF). 从 .NET Framework 4.0 开始,ContentPropertyAttribute 在 system.exception 程序集中。Starting with the .NET Framework 4.0, ContentPropertyAttribute is in the System.Xaml assembly. 有关详细信息,请参阅 Types Migrated from WPF to System.XamlFor more information, see Types Migrated from WPF to System.Xaml.

WPF 用法说明WPF Usage Notes

使用 ContentPropertyAttribute 的 Windows Presentation Foundation (WPF)中的类的示例 ContentControlButton 类从继承。An example of a class in Windows Presentation Foundation (WPF) that uses the ContentPropertyAttribute is ContentControl, which the Button class inherits from. ContentControl.Content 属性是由 ContentPropertyAttribute设置的内容属性。The ContentControl.Content property is the content property set by the ContentPropertyAttribute. 如果 Button 在 XAML 中实例化,ButtonContent 将设置为 "开始" 和 "结束" 按钮标记之间的元素。If a Button is instantiated in XAML, the Content of the Button will be set to the element that is between the start and end button tags.

构造函数

ContentPropertyAttribute()

初始化 ContentPropertyAttribute 类的新实例。Initializes a new instance of the ContentPropertyAttribute class.

ContentPropertyAttribute(String)

使用指定的名称初始化 ContentPropertyAttribute 类的新实例。Initializes a new instance of the ContentPropertyAttribute class, by using the specified name.

属性

Name

获取作为内容属性的属性的名称。Gets the name of the property that is the content property.

TypeId

在派生类中实现时,获取此 Attribute 的唯一标识符。When implemented in a derived class, gets a unique identifier for this Attribute.

(继承自 Attribute)

方法

Equals(Object)

返回一个值,该值指示此实例是否与指定的对象相等。Returns a value that indicates whether this instance is equal to a specified object.

(继承自 Attribute)
GetHashCode()

返回此实例的哈希代码。Returns the hash code for this instance.

(继承自 Attribute)
GetType()

获取当前实例的 TypeGets the Type of the current instance.

(继承自 Object)
IsDefaultAttribute()

在派生类中重写时,指示此实例的值是否是派生类的默认值。When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.

(继承自 Attribute)
Match(Object)

当在派生类中重写时,返回一个指示此实例是否等于指定对象的值。When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.

(继承自 Attribute)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
ToString()

返回表示当前对象的字符串。Returns a string that represents the current object.

(继承自 Object)

显式接口实现

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

将一组名称映射为对应的一组调度标识符。Maps a set of names to a corresponding set of dispatch identifiers.

(继承自 Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

检索对象的类型信息,然后可以使用该信息获取接口的类型信息。Retrieves the type information for an object, which can be used to get the type information for an interface.

(继承自 Attribute)
_Attribute.GetTypeInfoCount(UInt32)

检索对象提供的类型信息接口的数量(0 或 1)。Retrieves the number of type information interfaces that an object provides (either 0 or 1).

(继承自 Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

提供对某一对象公开的属性和方法的访问。Provides access to properties and methods exposed by an object.

(继承自 Attribute)

适用于

另请参阅