PropertyInfo 类

项目
08/17/2007

发现属性 (Property) 的属性 (Attribute) 并提供对属性 (Property) 元数据的访问。

**命名空间:**System.Reflection
**程序集:**mscorlib（在 mscorlib.dll 中）

语法

声明
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
<ClassInterfaceAttribute(ClassInterfaceType.None)> _
Public MustInherit Class PropertyInfo
    Inherits MemberInfo
    Implements _PropertyInfo
用法
Dim instance As PropertyInfo

[SerializableAttribute] 
[ComVisibleAttribute(true)] 
[ClassInterfaceAttribute(ClassInterfaceType.None)] 
public abstract class PropertyInfo : MemberInfo, _PropertyInfo

[SerializableAttribute] 
[ComVisibleAttribute(true)] 
[ClassInterfaceAttribute(ClassInterfaceType::None)] 
public ref class PropertyInfo abstract : public MemberInfo, _PropertyInfo

/** @attribute SerializableAttribute() */ 
/** @attribute ComVisibleAttribute(true) */ 
/** @attribute ClassInterfaceAttribute(ClassInterfaceType.None) */ 
public abstract class PropertyInfo extends MemberInfo implements _PropertyInfo

SerializableAttribute 
ComVisibleAttribute(true) 
ClassInterfaceAttribute(ClassInterfaceType.None) 
public abstract class PropertyInfo extends MemberInfo implements _PropertyInfo

备注

属性 (Property) 在逻辑上与字段相同。属性 (Property) 是已命名的对象状态的一个方面，它的值通常可通过 get 和 set 访问器访问。属性 (Property) 可以是只读的，这种情况下不支持 set 例程。

提示

若要确定某个属性 (Property) 是否为 static，必须通过调用 GetGetMethod 或 GetSetMethod 方法来获取 get 或 set 访问器的 MethodInfo，并检查它的 IsStatic 属性 (Property)。

此类中的多个方法假定属性 (Property) 的 get 访问器和 set 访问器方法具有某些格式。get 和 set 方法的签名必须符合下列约定：

get 方法的返回类型和 set 方法的最后一个参数必须相同。这是属性 (Property) 的类型。
get 和 set 方法的索引的数量、类型和顺序必须相同。

如果不遵循此格式，则 GetValue 和 SetValue 方法的行为是不确定的。

当 GetCustomAttributes 的 inherit 参数为 true 时，对 PropertyInfo 调用 ICustomAttributeProvider.GetCustomAttributes 不遍历类型层次结构。使用 System.Attribute 继承自定义属性 (Attribute)。

给继承者的说明 从 PropertyInfo 继承时，必须重写下列成员：GetValue、SetValue、GetAccessors、GetGetMethod、GetSetMethod 和 GetIndexParameters。

示例

本示例演示如何使用各种反射类来分析包含在程序集中的元数据。

Imports System
Imports System.Reflection

Module Module1

    Sub Main()
        ' This variable holds the amount of indenting that 
        ' should be used when displaying each line of information.
        Dim indent As Int32 = 0
        ' Display information about the EXE assembly.
        Dim a As [Assembly] = System.Reflection.Assembly.GetExecutingAssembly()
        Display(indent, "Assembly identity={0}", a.FullName)
        Display(indent + 1, "Codebase={0}", a.CodeBase)

        ' Display the set of assemblies our assemblies references.
        Dim an As AssemblyName
        Display(indent, "Referenced assemblies:")
        For Each an In a.GetReferencedAssemblies()
            Display(indent + 1, "Name={0}, Version={1}, Culture={2}, PublicKey token={3}", _
                an.Name, an.Version, an.CultureInfo.Name, BitConverter.ToString(an.GetPublicKeyToken))
        Next
        Display(indent, "")

        ' Display information about each assembly loading into this AppDomain.
        For Each a In AppDomain.CurrentDomain.GetAssemblies()
            Display(indent, "Assembly: {0}", a)

            ' Display information about each module of this assembly.
            Dim m As [Module]
            For Each m In a.GetModules(True)
                Display(indent + 1, "Module: {0}", m.Name)
            Next

            ' Display information about each type exported from this assembly.
            Dim t As Type
            indent += 1
            For Each t In a.GetExportedTypes()
                Display(0, "")
                Display(indent, "Type: {0}", t)

                ' For each type, show its members & their custom attributes.
                Dim mi As MemberInfo
                indent += 1
                For Each mi In t.GetMembers()
                    Display(indent, "Member: {0}", mi.Name)
                    DisplayAttributes(indent, mi)

                    ' If the member is a method, display information about its parameters.
                    Dim pi As ParameterInfo
                    If mi.MemberType = MemberTypes.Method Then
                        For Each pi In CType(mi, MethodInfo).GetParameters()
                            Display(indent + 1, "Parameter: Type={0}, Name={1}", pi.ParameterType, pi.Name)
                        Next
                    End If

                    ' If the member is a property, display information about the property's accessor methods.
                    If mi.MemberType = MemberTypes.Property Then
                        Dim am As MethodInfo
                        For Each am In CType(mi, PropertyInfo).GetAccessors()
                            Display(indent + 1, "Accessor method: {0}", am)
                        Next
                    End If
                Next
                indent -= 1
            Next
            indent -= 1
        Next
    End Sub

    ' Displays the custom attributes applied to the specified member.
    Sub DisplayAttributes(ByVal indent As Int32, ByVal mi As MemberInfo)
        ' Get the set of custom attributes; if none exist, just return.
        Dim attrs() As Object = mi.GetCustomAttributes(False)
        If attrs.Length = 0 Then Return

        ' Display the custom attributes applied to this member.
        Display(indent + 1, "Attributes:")
        Dim o As Object
        For Each o In attrs
            Display(indent + 2, "{0}", o.ToString())
        Next
    End Sub

    ' Display a formatted string indented by the specified amount.
    Sub Display(ByVal indent As Int32, ByVal format As String, ByVal ParamArray params() As Object)
        Console.Write(New String(" "c, indent * 2))
        Console.WriteLine(format, params)
    End Sub
End Module

'The output shown below is abbreviated.
'
'Assembly identity=Reflection, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null
'  Codebase=file:///C:/Reflection.exe
'Referenced assemblies:
'  Name=mscorlib, Version=1.0.5000.0, Culture=, PublicKey token=B7-7A-5C-56-19-34-E0-89
'  Name=Microsoft.VisualBasic, Version=7.0.5000.0, Culture=, PublicKey token=B0-3F-5F-7F-11-D5-0A-3A
'
'Assembly: mscorlib, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
'  Module: mscorlib.dll
'  Module: prc.nlp
'  Module: prcp.nlp
'  Module: ksc.nlp
'  Module: ctype.nlp
'  Module: xjis.nlp
'  Module: bopomofo.nlp
'  Module: culture.nlp
'  Module: region.nlp
'  Module: sortkey.nlp
'  Module: charinfo.nlp
'  Module: big5.nlp
'  Module: sorttbls.nlp
'  Module: l_intl.nlp
'  Module: l_except.nlp
'
'  Type: System.Object
'    Member: GetHashCode
'    Member: Equals
'      Parameter: Type=System.Object, Name=obj
'    Member: ToString
'    Member: Equals
'      Parameter: Type=System.Object, Name=objA
'      Parameter: Type=System.Object, Name=objB
'    Member: ReferenceEquals
'      Parameter: Type=System.Object, Name=objA
'      Parameter: Type=System.Object, Name=objB
'    Member: GetType
'    Member: .ctor
'
'  Type: System.ICloneable
'    Member: Clone
'
'  Type: System.Collections.IEnumerable
'    Member: GetEnumerator
'      Attributes:
'        System.Runtime.InteropServices.DispIdAttribute
'
'  Type: System.Collections.ICollection
'    Member: get_IsSynchronized
'    Member: get_SyncRoot
'    Member: get_Count
'    Member: CopyTo
'      Parameter: Type=System.Array, Name=array
'      Parameter: Type=System.Int32, Name=index
'    Member: Count
'      Accessor method: Int32 get_Count()
'    Member: SyncRoot
'      Accessor method: System.Object get_SyncRoot()
'    Member: IsSynchronized
'      Accessor method: Boolean get_IsSynchronized()
'

继承层次结构

System.Object
   System.Reflection.MemberInfo
    System.Reflection.PropertyInfo
       Microsoft.JScript.COMPropertyInfo
       System.Reflection.Emit.PropertyBuilder

线程安全

该类型对于多线程操作是安全的。

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

通过

PropertyInfo 类

语法

备注

示例

继承层次结构

线程安全

平台

版本信息

.NET Framework

.NET Compact Framework

请参见

参考

其他资源