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ParameterInfo Class

Definition

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

C#
public class ParameterInfo
C#
public class ParameterInfo : System.Reflection.ICustomAttributeProvider, System.Runtime.Serialization.IObjectReference
C#
public class ParameterInfo : System.Reflection.ICustomAttributeProvider
C#
[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
[System.Serializable]
public class ParameterInfo : System.Reflection.ICustomAttributeProvider, System.Runtime.InteropServices._ParameterInfo
C#
[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public class ParameterInfo : System.Reflection.ICustomAttributeProvider, System.Runtime.InteropServices._ParameterInfo
C#
[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public class ParameterInfo : System.Reflection.ICustomAttributeProvider, System.Runtime.InteropServices._ParameterInfo, System.Runtime.Serialization.IObjectReference
Inheritance
ParameterInfo
Attributes
Implements

Examples

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

C#
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

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.

ToString()

Returns a string that represents the current object.

(Inherited from Object)

Explicit Interface Implementations

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

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

_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.

_ParameterInfo.GetTypeInfoCount(UInt32)

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

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

Provides access to properties and methods exposed by an object.

ICustomAttributeProvider.GetCustomAttributes(Boolean)

Returns an array of all of the custom attributes defined on this member, excluding named attributes, or an empty array if there are no custom attributes.

ICustomAttributeProvider.GetCustomAttributes(Type, Boolean)

Returns an array of custom attributes defined on this member, identified by type, or an empty array if there are no custom attributes of that type.

ICustomAttributeProvider.IsDefined(Type, Boolean)

Indicates whether one or more instance of attributeType is defined on this member.

Extension Methods

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(ParameterInfo, Type)

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.

GetCustomAttribute<T>(ParameterInfo)

Retrieves a custom attribute of a specified type that is 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, 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(ParameterInfo, Type)

Retrieves a collection of custom attributes of a specified type that are applied to a specified parameter.

GetCustomAttributes(ParameterInfo)

Retrieves a collection of custom attributes 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.

GetCustomAttributes<T>(ParameterInfo)

Retrieves a collection of custom attributes of a specified type that 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.

IsDefined(ParameterInfo, Type)

Indicates whether custom attributes of a specified type are applied to a specified parameter.

Applies to

Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.1
UWP 10.0

Thread Safety

This type is thread safe.