ParameterInfo Class

 

Discovers the attributes of a parameter and provides access to parameter metadata.

Namespace:   System.Reflection
Assembly:  mscorlib (in mscorlib.dll)

System.Object
  System.Reflection.ParameterInfo

<SerializableAttribute>
<ClassInterfaceAttribute(ClassInterfaceType.None)>
<ComVisibleAttribute(True)>
Public Class ParameterInfo
	Implements _ParameterInfo, ICustomAttributeProvider, IObjectReference

NameDescription
System_CAPS_protmethodParameterInfo()

Initializes a new instance of the ParameterInfo class.

NameDescription
System_CAPS_pubpropertyAttributes

Gets the attributes for this parameter.

System_CAPS_pubpropertyCustomAttributes

Gets a collection that contains this parameter's custom attributes.

System_CAPS_pubpropertyDefaultValue

Gets a value indicating the default value if the parameter has a default value.

System_CAPS_pubpropertyHasDefaultValue

Gets a value that indicates whether this parameter has a default value.

System_CAPS_pubpropertyIsIn

Gets a value indicating whether this is an input parameter.

System_CAPS_pubpropertyIsLcid

Gets a value indicating whether this parameter is a locale identifier (lcid).

System_CAPS_pubpropertyIsOptional

Gets a value indicating whether this parameter is optional.

System_CAPS_pubpropertyIsOut

Gets a value indicating whether this is an output parameter.

System_CAPS_pubpropertyIsRetval

Gets a value indicating whether this is a Retval parameter.

System_CAPS_pubpropertyMember

Gets a value indicating the member in which the parameter is implemented.

System_CAPS_pubpropertyMetadataToken

Gets a value that identifies this parameter in metadata.

System_CAPS_pubpropertyName

Gets the name of the parameter.

System_CAPS_pubpropertyParameterType

Gets the Type of this parameter.

System_CAPS_pubpropertyPosition

Gets the zero-based position of the parameter in the formal parameter list.

System_CAPS_pubpropertyRawDefaultValue

Gets a value indicating the default value if the parameter has a default value.

NameDescription
System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_protmethodFinalize()

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)

System_CAPS_pubmethodGetCustomAttributes(Boolean)

Gets all the custom attributes defined on this parameter.

System_CAPS_pubmethodGetCustomAttributes(Type, Boolean)

Gets the custom attributes of the specified type or its derived types that are applied to this parameter.

System_CAPS_pubmethodGetCustomAttributesData()

Returns a list of CustomAttributeData objects for the current parameter, which can be used in the reflection-only context.

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetOptionalCustomModifiers()

Gets the optional custom modifiers of the parameter.

System_CAPS_pubmethodGetRealObject(StreamingContext)

Returns the real object that should be deserialized instead of the object that the serialized stream specifies.

System_CAPS_pubmethodGetRequiredCustomModifiers()

Gets the required custom modifiers of the parameter.

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodIsDefined(Type, Boolean)

Determines whether the custom attribute of the specified type or its derived types is applied to this parameter.

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_pubmethodToString()

Gets the parameter type and name represented as a string.(Overrides Object.ToString().)

NameDescription
System_CAPS_protfieldAttrsImpl

The attributes of the parameter.

System_CAPS_protfieldClassImpl

The Type of the parameter.

System_CAPS_protfieldDefaultValueImpl

The default value of the parameter.

System_CAPS_protfieldMemberImpl

The member in which the field is implemented.

System_CAPS_protfieldNameImpl

The name of the parameter.

System_CAPS_protfieldPositionImpl

The zero-based position of the parameter in the parameter list.

NameDescription
System_CAPS_pubinterfaceSystem_CAPS_privmethod_ParameterInfo.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.

System_CAPS_pubinterfaceSystem_CAPS_privmethod_ParameterInfo.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can then be used to get the type information for an interface.

System_CAPS_pubinterfaceSystem_CAPS_privmethod_ParameterInfo.GetTypeInfoCount(UInt32)

Retrieves the number of type information interfaces that an object provides (either 0 or 1).

System_CAPS_pubinterfaceSystem_CAPS_privmethod_ParameterInfo.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.

NameDescription
System_CAPS_pubmethodGetCustomAttribute(Type)

Overloaded. Retrieves a custom attribute of a specified type that is applied to a specified parameter.(Defined by CustomAttributeExtensions.)

System_CAPS_pubmethodGetCustomAttribute(Type, Boolean)

Overloaded. Retrieves a custom attribute of a specified type that is applied to a specified parameter, and optionally inspects the ancestors of that parameter.(Defined by CustomAttributeExtensions.)

System_CAPS_pubmethodGetCustomAttribute(Of T)()

Overloaded. Retrieves a custom attribute of a specified type that is applied to a specified parameter.(Defined by CustomAttributeExtensions.)

System_CAPS_pubmethodGetCustomAttribute(Of T)(Boolean)

Overloaded. Retrieves a custom attribute of a specified type that is applied to a specified parameter, and optionally inspects the ancestors of that parameter.(Defined by CustomAttributeExtensions.)

System_CAPS_pubmethodGetCustomAttributes()

Overloaded. Retrieves a collection of custom attributes that are applied to a specified parameter.(Defined by CustomAttributeExtensions.)

System_CAPS_pubmethodGetCustomAttributes(Type)

Overloaded. Retrieves a collection of custom attributes of a specified type that are applied to a specified parameter.(Defined by CustomAttributeExtensions.)

System_CAPS_pubmethodGetCustomAttributes(Of T)(Boolean)

Overloaded. Retrieves a collection of custom attributes of a specified type that are applied to a specified parameter, and optionally inspects the ancestors of that parameter.(Defined by CustomAttributeExtensions.)

System_CAPS_pubmethodIsDefined(Type)

Overloaded. Indicates whether custom attributes of a specified type are applied to a specified parameter.(Defined by CustomAttributeExtensions.)

Use an instance of ParameterInfo to obtain information about the parameter's data type, default value, and so on.

GetParameters returns an array of ParameterInfo objects representing the parameters of a method, in order.

This example shows how to use various reflection classes to analyze the metadata contained in an assembly.

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 = GetType(Module1).Assembly
        Display(indent, "Assembly identity={0}", a.FullName)
        Display(indent + 1, "Codebase={0}", a.CodeBase)

        ' Display the set of assemblies our assemblies reference.
        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()
'

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1

This type is thread safe.

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