ParameterInfo Class

Definition

Namespace:

System.Reflection

Assembly:

System.Runtime.dll

Source:

ParameterInfo.cs

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

public ref class ParameterInfo : System::Reflection::ICustomAttributeProvider, System::Runtime::Serialization::IObjectReference

public class ParameterInfo : System.Reflection.ICustomAttributeProvider, System.Runtime.Serialization.IObjectReference

type ParameterInfo = class
    interface ICustomAttributeProvider
    interface IObjectReference

Public Class ParameterInfo
Implements ICustomAttributeProvider, IObjectReference

Inheritance

Object

ParameterInfo

Implements

ICustomAttributeProvider IObjectReference

Examples

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

using namespace System;
using namespace System::Reflection;

static void Display(Int32 indent, String^ format, ... array<Object^>^param) 
{
    Console::Write("{0}", gcnew String (' ', indent));
    Console::WriteLine(format, param);
}
    
// Displays the custom attributes applied to the specified member.
static void DisplayAttributes(Int32 indent, MemberInfo^ mi)
{
    // Get the set of custom attributes; if none exist, just return.
    array<Object^>^attrs = mi->GetCustomAttributes(false);
        
    if (attrs->Length==0)
    {
        return;          
    }
        
    // Display the custom attributes applied to this member.
    Display(indent+1, "Attributes:");
    for each ( Object^ o in attrs )
    {
        Display(indent*2, "{0}", o);
    }				
}

void main()
{
    try
    {
        // This variable holds the amount of indenting that 
        // should be used when displaying each line of information.
        Int32 indent = 0; 
        // Display information about the EXE assembly.
        Assembly^ a = System::Reflection::Assembly::GetExecutingAssembly();
        
        Display(indent, "Assembly identity={0}", gcnew array<Object^> {a->FullName});
        Display(indent+1, "Codebase={0}", gcnew array<Object^> {a->CodeBase});

        // Display the set of assemblies our assemblies reference.
  
        Display(indent, "Referenced assemblies:"); 

        for each ( AssemblyName^ an in a->GetReferencedAssemblies() )
        {
            Display(indent + 1, "Name={0}, Version={1}, Culture={2}, PublicKey token={3}", gcnew array<Object^> {an->Name, an->Version, an->CultureInfo, (BitConverter::ToString(an->GetPublicKeyToken()))});
        }
        Display(indent, "");  
        // Display information about each assembly loading into this AppDomain. 
        for each ( Assembly^ b in AppDomain::CurrentDomain->GetAssemblies()) 
        {
            Display(indent, "Assembly: {0}", gcnew array<Object^> {b});
            // Display information about each module of this assembly.
 
            for each ( Module^ m in b->GetModules(true) ) 
            {
                Display(indent+1, "Module: {0}", gcnew array<Object^> {m->Name});
            }
            // Display information about each type exported from this assembly.
           
            indent += 1; 
            for each ( Type^ t in b->GetExportedTypes() ) 
            {
                Display(0, "");  
                Display(indent, "Type: {0}", gcnew array<Object^> {t}); 

                // For each type, show its members & their custom attributes.
           
                indent += 1; 
                for each (MemberInfo^ mi in t->GetMembers() )
                {
                    Display(indent, "Member: {0}", gcnew array<Object^> {mi->Name}); 
                    DisplayAttributes(indent, mi);

                    // If the member is a method, display information about its parameters.         
                    if (mi->MemberType==MemberTypes::Method) 
                    {
                    
                        for each ( ParameterInfo^ pi in (((MethodInfo^) mi)->GetParameters()))
                        {
                            Display(indent+1, "Parameter: Type={0}, Name={1}", gcnew array<Object^> {pi->ParameterType, pi->Name}); 
                        }
                    }

                    // If the member is a property, display information about the property's accessor methods.
                    if (mi->MemberType==MemberTypes::Property) 
                    {
                        for each ( MethodInfo^ am in (((PropertyInfo^) mi)->GetAccessors()) )
                        {
                            Display(indent+1, "Accessor method: {0}", gcnew array<Object^> {am});
                        }
                    }
                }
                // Display a formatted string indented by the specified amount.               
                indent -= 1;
            }
            indent -= 1;
        }
    }
    catch (Exception^ e)
    {
        Console::WriteLine(e->Message);
    }
}

// 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()
//

using System;
using System.Reflection;

class Module1
{
    public static void Main()
    {
        // This variable holds the amount of indenting that
        // should be used when displaying each line of information.
        Int32 indent = 0;
        // Display information about the EXE assembly.
        Assembly a = typeof(Module1).Assembly;
        Display(indent, "Assembly identity={0}", a.FullName);
        Display(indent+1, "Codebase={0}", a.CodeBase);

        // Display the set of assemblies our assemblies reference.

        Display(indent, "Referenced assemblies:");
        foreach (AssemblyName 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.
        foreach (Assembly b in AppDomain.CurrentDomain.GetAssemblies())
        {
            Display(indent, "Assembly: {0}", b);

            // Display information about each module of this assembly.
            foreach ( Module m in b.GetModules(true) )
            {
                Display(indent+1, "Module: {0}", m.Name);
            }

            // Display information about each type exported from this assembly.

            indent += 1;
            foreach ( Type t in b.GetExportedTypes() )
            {
                Display(0, "");
                Display(indent, "Type: {0}", t);

                // For each type, show its members & their custom attributes.

                indent += 1;
                foreach (MemberInfo mi in t.GetMembers() )
                {
                    Display(indent, "Member: {0}", mi.Name);
                    DisplayAttributes(indent, mi);

                    // If the member is a method, display information about its parameters.

                    if (mi.MemberType==MemberTypes.Method)
                    {
                        foreach ( ParameterInfo pi in ((MethodInfo) mi).GetParameters() )
                        {
                            Display(indent+1, "Parameter: Type={0}, Name={1}", pi.ParameterType, pi.Name);
                        }
                    }

                    // If the member is a property, display information about the property's accessor methods.
                    if (mi.MemberType==MemberTypes.Property)
                    {
                        foreach ( MethodInfo am in ((PropertyInfo) mi).GetAccessors() )
                        {
                            Display(indent+1, "Accessor method: {0}", am);
                        }
                    }
                }
                indent -= 1;
            }
            indent -= 1;
        }
    }

    // Displays the custom attributes applied to the specified member.
    public static void DisplayAttributes(Int32 indent, MemberInfo mi)
    {
        // Get the set of custom attributes; if none exist, just return.
        object[] attrs = mi.GetCustomAttributes(false);
        if (attrs.Length==0) {return;}

        // Display the custom attributes applied to this member.
        Display(indent+1, "Attributes:");
        foreach ( object o in attrs )
        {
            Display(indent+2, "{0}", o.ToString());
        }
    }

    // Display a formatted string indented by the specified amount.
    public static void Display(Int32 indent, string format, params object[] param)

    {
        Console.Write(new string(' ', indent*2));
        Console.WriteLine(format, param);
    }
}

//The output shown below is abbreviated.
//
//Assembly identity=ReflectionCS, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
//  Codebase=file:///C:/Documents and Settings/test/My Documents/Visual Studio 2005/Projects/Reflection/Reflection/obj/Debug/Reflection.exe
//Referenced assemblies:
//  Name=mscorlib, Version=2.0.0.0, Culture=, PublicKey token=B7-7A-5C-56-19-34-E0-89
//
//Assembly: mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//  Module: mscorlib.dll
//
//  Type: System.Object
//    Member: GetType
//    Member: ToString
//    Member: Equals
//      Parameter: Type=System.Object, Name=obj
//    Member: Equals
//      Parameter: Type=System.Object, Name=objA
//      Parameter: Type=System.Object, Name=objB
//    Member: ReferenceEquals
//      Attributes:
//        System.Runtime.ConstrainedExecution.ReliabilityContractAttribute
//      Parameter: Type=System.Object, Name=objA
//      Parameter: Type=System.Object, Name=objB
//    Member: GetHashCode
//    Member: .ctor
//      Attributes:
//        System.Runtime.ConstrainedExecution.ReliabilityContractAttribute
//
//  Type: System.ICloneable
//    Member: Clone
//
//  Type: System.Collections.IEnumerable
//    Member: GetEnumerator
//      Attributes:
//        System.Runtime.InteropServices.DispIdAttribute
//
//  Type: System.Collections.ICollection
//    Member: CopyTo
//      Parameter: Type=System.Array, Name=array
//      Parameter: Type=System.Int32, Name=index
//    Member: get_Count
//    Member: get_SyncRoot
//    Member: get_IsSynchronized
//    Member: Count
//      Accessor method: Int32 get_Count()
//    Member: SyncRoot
//      Accessor method: System.Object get_SyncRoot()
//    Member: IsSynchronized
//      Accessor method: Boolean get_IsSynchronized()
//
//  Type: System.Collections.IList
//    Member: get_Item
//      Parameter: Type=System.Int32, Name=index
//    Member: set_Item
//      Parameter: Type=System.Int32, Name=index
//      Parameter: Type=System.Object, Name=value
//    Member: Add
//      Parameter: Type=System.Object, Name=value
//    Member: Contains
//      Parameter: Type=System.Object, Name=value
//    Member: Clear
//    Member: get_IsReadOnly
//    Member: get_IsFixedSize
//    Member: IndexOf
//      Parameter: Type=System.Object, Name=value
//    Member: Insert
//      Parameter: Type=System.Int32, Name=index
//      Parameter: Type=System.Object, Name=value
//    Member: Remove
//      Parameter: Type=System.Object, Name=value
//    Member: RemoveAt
//      Parameter: Type=System.Int32, Name=index
//    Member: Item
//      Accessor method: System.Object get_Item(Int32)
//      Accessor method: Void set_Item(Int32, System.Object)
//    Member: IsReadOnly
//      Accessor method: Boolean get_IsReadOnly()
//    Member: IsFixedSize
//      Accessor method: Boolean get_IsFixedSize()
//
//  Type: System.Array
//    Member: IndexOf
//      Parameter: Type=T[], Name=array
//      Parameter: Type=T, Name=value
//    Member: AsReadOnly
//      Parameter: Type=T[], Name=array
//    Member: Resize
//      Attributes:
//        System.Runtime.ConstrainedExecution.ReliabilityContractAttribute
//      Parameter: Type=T[]&, Name=array
//      Parameter: Type=System.Int32, Name=newSize
//    Member: BinarySearch
//      Attributes:
//        System.Runtime.ConstrainedExecution.ReliabilityContractAttribute
//      Parameter: Type=T[], Name=array
//      Parameter: Type=T, Name=value
//    Member: BinarySearch
//      Attributes:
//        System.Runtime.ConstrainedExecution.ReliabilityContractAttribute
//      Parameter: Type=T[], Name=array
//      Parameter: Type=T, Name=value
//      Parameter: Type=System.Collections.Generic.IComparer`1[T], Name=comparer

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()
'

Remarks

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.

Constructors

ParameterInfo()

Initializes a new instance of the ParameterInfo class.

Fields

AttrsImpl	The attributes of the parameter.
ClassImpl	The Type of the parameter.
DefaultValueImpl	The default value of the parameter.
MemberImpl	The member in which the field is implemented.
NameImpl	The name of the parameter.
PositionImpl	The zero-based position of the parameter in the parameter list.

Properties

Attributes	Gets the attributes for this parameter.
CustomAttributes	Gets a collection that contains this parameter's custom attributes.
DefaultValue	Gets a value indicating the default value if the parameter has a default value.
HasDefaultValue	Gets a value that indicates whether this parameter has a default value.
IsIn	Gets a value indicating whether this is an input parameter.
IsLcid	Gets a value indicating whether this parameter is a locale identifier (lcid).
IsOptional	Gets a value indicating whether this parameter is optional.
IsOut	Gets a value indicating whether this is an output parameter.
IsRetval	Gets a value indicating whether this is a Retval parameter.
Member	Gets a value indicating the member in which the parameter is implemented.
MetadataToken	Gets a value that identifies this parameter in metadata.
Name	Gets the name of the parameter.
ParameterType	Gets the Type of this parameter.
Position	Gets the zero-based position of the parameter in the formal parameter list.
RawDefaultValue	Gets a value indicating the default value if the parameter has a default value.

Methods

Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetCustomAttributes(Boolean)	Gets all the custom attributes defined on this parameter.
GetCustomAttributes(Type, Boolean)	Gets the custom attributes of the specified type or its derived types that are applied to this parameter.
GetCustomAttributesData()	Returns a list of CustomAttributeData objects for the current parameter, which can be used in the reflection-only context.
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetModifiedParameterType()	Gets the modified type of this parameter object.
GetOptionalCustomModifiers()	Gets the optional custom modifiers of the parameter.
GetRealObject(StreamingContext)	Obsolete. Returns the real object that should be deserialized instead of the object that the serialized stream specifies.
GetRequiredCustomModifiers()	Gets the required custom modifiers of the parameter.
GetType()	Gets the Type of the current instance. (Inherited from Object)
IsDefined(Type, Boolean)	Determines whether the custom attribute of the specified type or its derived types is applied to this parameter.
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Gets the parameter type and name represented as a string.

Extension Methods

GetCustomAttribute(ParameterInfo, Type)	Retrieves a custom attribute of a specified type that is applied to a specified parameter.
GetCustomAttribute(ParameterInfo, Type, Boolean)	Retrieves a custom attribute of a specified type that is applied to a specified parameter, and optionally inspects the ancestors of that parameter.
GetCustomAttribute<T>(ParameterInfo)	Retrieves a custom attribute of a specified type that is applied to a specified parameter.
GetCustomAttribute<T>(ParameterInfo, Boolean)	Retrieves a custom attribute of a specified type that is applied to a specified parameter, and optionally inspects the ancestors of that parameter.
GetCustomAttributes(ParameterInfo)	Retrieves a collection of custom attributes that are applied to a specified parameter.
GetCustomAttributes(ParameterInfo, Boolean)	Retrieves a collection of custom attributes that are applied to a specified parameter, and optionally inspects the ancestors of that parameter.
GetCustomAttributes(ParameterInfo, Type)	Retrieves a collection of custom attributes of a specified type that are applied to a specified parameter.
GetCustomAttributes(ParameterInfo, Type, Boolean)	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.
GetCustomAttributes<T>(ParameterInfo)	Retrieves a collection of custom attributes of a specified type that are applied to a specified parameter.
GetCustomAttributes<T>(ParameterInfo, Boolean)	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.
IsDefined(ParameterInfo, Type)	Indicates whether custom attributes of a specified type are applied to a specified parameter.
IsDefined(ParameterInfo, Type, Boolean)	Indicates whether custom attributes of a specified type are applied to a specified parameter, and, optionally, applied to its ancestors.

Thread Safety

This type is thread safe.