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ParameterInfo Class

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

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

<SerializableAttribute> _
<ClassInterfaceAttribute(ClassInterfaceType.None)> _
<ComVisibleAttribute(True)> _
Public Class ParameterInfo _
	Implements _ParameterInfo, ICustomAttributeProvider
Dim instance As ParameterInfo

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
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))
        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)

            ' 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)
                    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)
                    End If 
                indent -= 1
            indent -= 1
    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())
    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=, 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() 


This type is thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0