ParameterInfo Class

Represents a parameter of a method or constructor. This class cannot be inherited.

Summary

The ParameterInfo class is a core component of the .NET Reflection API. It provides access to metadata about a method or constructor parameter, such as its name, type, default value, attributes, and position within the parameter list.

Inheritance Hierarchy

System.Object
    System.Reflection.ParameterInfo

Members

• MemberInfo Member { get; }
  Gets the method or constructor that contains this parameter.
• string Name { get; }
  Gets the name of the parameter.
• Type ParameterType { get; }
  Gets the type of the parameter.
• int Position { get; }
  Gets the zero-based position of the parameter in the method or constructor signature.
• object DefaultValue { get; }
  Gets the default value of the parameter.
• ParameterAttributes Attributes { get; }
  Gets the attributes of the parameter.
• bool IsOut { get; }
  Gets a value indicating whether the parameter is marked with the out keyword.
• bool IsOptional { get; }
  Gets a value indicating whether the parameter is optional.
• bool IsIn { get; }
  Gets a value indicating whether the parameter is marked with the in keyword.
• bool IsLcid { get; }
  Gets a value indicating whether the parameter is marked with the lcid attribute.
• bool IsRetval { get; }
  Gets a value indicating whether the parameter is the return value of the method.
• bool HasDefaultValue { get; }
  Gets a value indicating whether the parameter has a default value.

Remarks

You can obtain ParameterInfo objects by invoking the GetParameters() method on a MethodInfo or ConstructorInfo object.

Example

using System;
using System.Reflection;

public class Example
{
    public static void SampleMethod(int count, string name = "Default", bool flag = true) { }

    public static void Main(string[] args)
    {
        MethodInfo method = typeof(Example).GetMethod("SampleMethod");
        ParameterInfo[] parameters = method.GetParameters();

        Console.WriteLine($"Parameters for {method.Name}:");

        foreach (ParameterInfo parameter in parameters)
        {
            Console.WriteLine("--------------------");
            Console.WriteLine($"Name: {parameter.Name}");
            Console.WriteLine($"Type: {parameter.ParameterType.Name}");
            Console.WriteLine($"Position: {parameter.Position}");
            Console.WriteLine($"IsOptional: {parameter.IsOptional}");
            Console.WriteLine($"HasDefaultValue: {parameter.HasDefaultValue}");
            if (parameter.HasDefaultValue)
            {
                Console.WriteLine($"DefaultValue: {parameter.DefaultValue}");
            }
            Console.WriteLine($"Attributes: {parameter.Attributes}");
        }
    }
}
        

Parameters for SampleMethod:
--------------------
Name: count
Type: Int32
Position: 0
IsOptional: False
HasDefaultValue: False
Attributes: None
--------------------
Name: name
Type: String
Position: 1
IsOptional: True
HasDefaultValue: True
DefaultValue: Default
Attributes: Optional
--------------------
Name: flag
Type: Boolean
Position: 2
IsOptional: True
HasDefaultValue: True
DefaultValue: True
Attributes: Optional
            

Requirements

Namespace: System.Reflection

Assembly: System.Private.CoreLib (in System.Private.CoreLib.dll)