MethodInfo.GetBaseDefinition Method

When overridden in a derived class, returns the MethodInfo object for the method on the direct or indirect base class in which the method represented by this instance was first declared.

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

public abstract MethodInfo GetBaseDefinition()

Return Value

Type: System.Reflection.MethodInfo
A MethodInfo object for the first implementation of this method.



GetBaseDefinition returns the first definition of the specified method in the class hierarchy.

If the method is declared on an interface, GetBaseDefinition returns the method.

If the method is defined in a base class, then GetBaseDefinition works as follows:

  • If a given method overrides a virtual definition in the base class, the virtual definition is returned.

  • If a given method is specified with the new keyword (as in newslot as described in Common Type System), the given method is returned.

  • If the method is not defined in the type of the object on which GetBaseDefinition is called, the method definition highest in the class hierarchy is returned.

To get the GetBaseDefinition method, first get the class Type. From the Type, get the MethodInfo. From the MethodInfo, get the GetBaseDefinition.

This code example demonstrates the behavior of GetBaseDefinition.

using System;
using System.Reflection;

public class GetBaseDef {
    public static void Main(String[] args)
    Type t = typeof(B);
    MethodInfo m;

    // Print A Void B().
    m = t.GetMethod("B");
    Console.WriteLine(m.GetBaseDefinition().DeclaringType + " " + m.GetBaseDefinition());

    // Print A Void C().
    m = t.GetMethod("C");
    Console.WriteLine(m.GetBaseDefinition().DeclaringType + " " + m.GetBaseDefinition());

    // Print B Void D().
    m = t.GetMethod("D", (BindingFlags.Public |
                  BindingFlags.Instance |
    Console.WriteLine(m.GetBaseDefinition().DeclaringType + " " + m.GetBaseDefinition());


public class A
    public virtual void B() { Console.WriteLine("C"); }
    public virtual void C() { Console.WriteLine("C"); }
    public virtual void D() { Console.WriteLine("E"); }

public class B : A
    public override void C() { Console.WriteLine("C"); }
    public new void D()  { Console.WriteLine("D"); }

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

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