System.Reflection.MethodBase Class

public abstract class MethodBase : MemberInfo

Base Types

Object
  MemberInfo
    MethodBase

Assembly

mscorlib

Library

Reflection

Summary

Provides information about methods and constructors.

Description

[Note: MethodBase is used to represent method types.

The Base Class Library includes the following derived types:

• MethodInfo
• ConstructorInfo

]

See Also

System.Reflection Namespace

Members

MethodBase Constructors

MethodBase Constructor

MethodBase Methods

MethodBase.GetGenericArguments Method
MethodBase.GetMethodFromHandle Method
MethodBase.GetParameters Method
MethodBase.Invoke(System.Object, System.Reflection.BindingFlags, System.Reflection.Binder, System.Object[], System.Globalization.CultureInfo) Method
MethodBase.Invoke(System.Object, System.Object[]) Method

MethodBase Properties

MethodBase.Attributes Property
MethodBase.ContainsGenericParameters Property
MethodBase.IsGenericMethod Property
MethodBase.IsGenericMethodDefinition Property

Constructs a new instance of the MethodBase class.

See Also

System.Reflection.MethodBase Class, System.Reflection Namespace

Returns an array of Type objects that represent the type arguments of a generic method or the type parameters of a generic method definition.

Return Value

An array of Type objects that represent the type arguments of a generic method or the type parameters of a generic method definition. Returns an empty array if the current method is not a generic method.

Exceptions

Exception Type	Condition
NotSupportedException	Default behavior when not overridden in a derived class.

Description

The default behavior, when not overridden in a derived class, is to throw NotSupportedException. In other words, derived classes do not support generics by default.

The elements of the returned array are in the order in which they appear in the list of type parameters for the generic method.

• If the current method is a closed constructed method (that is, the System.Reflection.MethodBase.ContainsGenericParameters property returns false ), the array returned by the System.Reflection.MethodBase.GetGenericArguments method contains the types that have been assigned to the generic type parameters of the generic method definition.

• If the current method is a generic method definition, the array contains the type parameters.

• If the current method is an open constructed method (that is, the System.Reflection.MethodBase.ContainsGenericParameters property returns true ) in which specific types have been assigned to some type parameters and type parameters of enclosing generic types have been assigned to other type parameters, the array contains both types and type parameters. Use the System.Type.IsGenericParameter property to tell them apart.

For a list of the invariant conditions for terms specific to generic methods, see the System.Reflection.MethodInfo.IsGenericMethod property. For a list of the invariant conditions for other terms used in generic reflection, see the System.Type.IsGenericType property.

See Also

System.Reflection.MethodBase Class, System.Reflection Namespace

handle

The method's RuntimeMethodHandle handle.

Return Value

A MethodBase object containing information about the method.

Description

The handles are valid only in the application domain in which they were obtained.

Library

RuntimeInfrastructure

See Also

System.Reflection.MethodBase Class, System.Reflection Namespace

An array of ParameterInfo objects that contain information that matches the signature of the method or constructor reflected by the current instance.

Description

[Behaviors: As described above.]

See Also

System.Reflection.MethodBase Class, System.Reflection Namespace

obj

An instance of the type that contains the method reflected by the current instance. If the method is static, obj is ignored. For non-static methods, obj is an instance of a class that inherits or declares the method.

invokeAttr

A BindingFlags value that controls the binding process.

binder

An object that enables the binding, coercion of argument types, invocation of members, and retrieval of MemberInfo objects via reflection. If binder is null , the default binder is used.

parameters

An array of objects that match the number, order and type of the parameters for the constructor or method reflected by the current instance. If the member reflected by the current instance takes no parameters, specify either an array with zero elements or null . [Note: Any object in this array that is not explicitly initialized with a value will contain the default value for that object type. For reference-type elements, this value is null . For value-type elements, this value is 0, 0.0, or false , depending on the specific element type. If the method or constructor reflected by the current instance is static , this parameter is ignored.]

culture

The only defined value for this parameter is null .

Return Value

A Object that contains the return value of the invoked method, or a re-initialized object if a constructor was invoked.

Exceptions

Exception Type	Condition
ArgumentException	The types of the elements of parameters do not match the types of the parameters accepted by the constructor or method reflected by the current instance, under the constraints of the default binder.
TargetException	The constructor or method reflected by the current instance is non-static, and obj is null or is of a type that does not implement the member reflected by the current instance.
TargetInvocationException	The method reflected by the current instance threw an exception.
TargetParameterCountException	parameters.Length does not equal the number of parameters required by the contract of the constructor or method reflected by the current instance.
MemberAccessException	The caller does not have permission to execute the method or constructor.
InvalidOperationException	The type that declares the method is an open generic type. That is, System.Type.ContainsGenericParameters returns true for the declaring type.

Description

Optional parameters can not be omitted in calls to System.Reflection.MethodBase.Invoke(System.Object,System.Object[]) .

See Also

System.Reflection.MethodBase Class, System.Reflection Namespace

A Object that contains the return value of the invoked method, or a re-initialized object if a constructor was invoked.

Exceptions

Exception Type	Condition
ArgumentException	The types of the elements of parameters do not match the types of the parameters accepted by the constructor or method reflected by the current instance, under the constraints of the default binder.
TargetException	The constructor or method reflected by the current instance is non-static and obj is null , or is of a type that does not implement the member reflected by the current instance.
TargetInvocationException	The constructor or method reflected by the current instance threw an exception.
TargetParameterCountException	parameters.Length does not equal the number of parameters required by the contract of the member reflected by the current instance.
MemberAccessException	The caller does not have permission to execute the method or constructor.
InvalidOperationException	The type that declares the method is an open generic type. That is, System.Type.ContainsGenericParameters returns true for the declaring type.

Description

This version of System.Reflection.MethodBase.Invoke(System.Object,System.Object[]) is equivalent to System.Reflection.MethodBase.Invoke(System.Object,System.Object[])(obj, (BindingFlags )0, null , parameters, null ).

Optional parameters cannot be omitted in calls to System.Reflection.MethodBase.Invoke(System.Object,System.Object[]) .

See Also

System.Reflection.MethodBase Class, System.Reflection Namespace

A MethodAttributes value that signifies the attributes of the method reflected by the current instance.

Description

[Behaviors: This property is read-only.

This property gets a MethodAttributes value that indicates the attributes set in the metadata of the method reflected by the current instance.

]

[Usage: Use this property to determine the accessibility, layout, and semantics of the constructor or method reflected by the current instance. Also use this property to determine if the member reflected by the current instance is implemented in native code or has a special name.]

Example

The following example demonstrates using this property to obtain the attributes of three methods.

using System;
using System.Reflection;

abstract class MyBaseClass
{

   abstract public void MyPublicInstanceMethod();

}

class MyDerivedClass : MyBaseClass
{

   public override void MyPublicInstanceMethod() {}
   private static void MyPrivateStaticMethod() {}

}

class MethodAttributesExample
{

   static void PrintMethodAttributes(Type t)
   {

      string str;
      MethodInfo[] miAry = t.GetMethods( BindingFlags.Static |
         BindingFlags.Instance | BindingFlags.Public |
         BindingFlags.NonPublic | BindingFlags.DeclaredOnly );
      foreach (MethodInfo mi in miAry)
      {

         Console.WriteLine("Method {0} is: ", mi.Name);
         str = ((mi.Attributes & MethodAttributes.Static) != 0) ?
            "Static" : "Instance";
         Console.Write(str + " ");
         str = ((mi.Attributes & MethodAttributes.Public) != 0) ?
            "Public" : "Not-Public";
         Console.Write(str + " ");
         str = ((mi.Attributes & MethodAttributes.HideBySig) != 0) ?
            "HideBySig" : "Hide-by-name";
         Console.Write(str + " ");
         str = ((mi.Attributes & MethodAttributes.Abstract) != 0) ?
            "Abstract" : String.Empty;
         Console.WriteLine(str);

      }

   }

   public static void Main()
   {

      PrintMethodAttributes(typeof(MyBaseClass));
      PrintMethodAttributes(typeof(MyDerivedClass));

   }

}
      

The output is

Method MyPublicInstanceMethod is:

Instance Public HideBySig Abstract

Method MyPublicInstanceMethod is:

Instance Public HideBySig

Method MyPrivateStaticMethod is:

Static Not-Public HideBySig

See Also

System.Reflection.MethodBase Class, System.Reflection Namespace

System.Reflection.MethodBase Class, System.Reflection Namespace

The default behavior, when not overridden in a derived class, is to return false . In other words, by default, derived classes do not support generics.

Use this property to determine whether the current MethodBase object represents a generic method. Use the System.Reflection.MethodBase.ContainsGenericParameters property to determine whether the current MethodBase object represents an open constructed method or a closed constructed method.

For a list of the invariant conditions for terms specific to generic methods, see the System.Reflection.MethodInfo.IsGenericMethod property. For a list of the invariant conditions for other terms used in generic reflection, see the System.Type.IsGenericType property.

[Behaviors: This property is read-only.

]

See Also

System.Reflection.MethodBase Class, System.Reflection Namespace

true if the current MethodBase object represents the definition of a generic method; otherwise false .

Description

The default behavior, when not overridden in a derived class, is to return false . In other words, by default, derived classes do not support generics.

If the current MethodBase represents a generic method definition, then:

• System.Reflection.MethodBase.IsGenericMethodDefinition returns true .

• For each Type object in the array returned by the System.Reflection.MethodBase.GetGenericArguments method: The System.Type.IsGenericParameter property returns true ; the System.Type.DeclaringMethod returns the current instance; and the System.Type.GenericParameterPosition property is the same as the position of the Type object in the array.

For a list of the invariant conditions for terms specific to generic methods, see the System.Reflection.MethodInfo.IsGenericMethod property. For a list of the invariant conditions for other terms used in generic reflection, see the System.Type.IsGenericType property.

[Behaviors: This property is read-only.

]

See Also

System.Reflection.MethodBase Class, System.Reflection Namespace