MethodBase.IsVirtual Property

Definition

Gets a value indicating whether the method is virtual.

C#
public bool IsVirtual { get; }

Property Value

true if this method is virtual; otherwise, false.

Implements

Examples

The following example displays false for IsFinal, which might lead you to think that MyMethod is overridable. The code prints false even though MyMethod is not marked virtual and thus cannot be overridden.

C#
using System;
using System.Reflection;

public class MyClass
{
    public void MyMethod()
    {
    }
    public static void Main()
    {
        MethodBase m = typeof(MyClass).GetMethod("MyMethod");
        Console.WriteLine("The IsFinal property value of MyMethod is {0}.", m.IsFinal);
        Console.WriteLine("The IsVirtual property value of MyMethod is {0}.", m.IsVirtual);
    }
}

Remarks

A virtual member may reference instance data in a class and must be referenced through an instance of the class.

To determine if a method is overridable, it is not sufficient to check that IsVirtual is true. For a method to be overridable, IsVirtual must be true and IsFinal must be false. For example, a method might be non-virtual, but it implements an interface method. The common language runtime requires that all methods that implement interface members must be marked as virtual; therefore, the compiler marks the method virtual final. So there are cases where a method is marked as virtual but is still not overridable.

To establish with certainty whether a method is overridable, use code such as this:

C#
if (MethodInfo.IsVirtual && !MethodInfo.IsFinal)

If IsVirtual is false or IsFinal is true, then the method cannot be overridden.

You can determine whether the current method overrides a method in a base class by calling the MethodInfo.GetBaseDefinition method. The following example implements an IsOverride method that does this.

C#
using System;
using System.Reflection;

public class ReflectionUtilities
{   
   public static bool IsOverride(MethodInfo method)
   {
      return ! method.Equals(method.GetBaseDefinition());
   }
}

public class Example
{
   public static void Main()
   {
      MethodInfo equals = typeof(Int32).GetMethod("Equals", 
                                        new Type[] { typeof(Object) } );
      Console.WriteLine("{0}.{1} is inherited: {2}", 
                        equals.ReflectedType.Name, equals.Name,
                        ReflectionUtilities.IsOverride(equals));
      
      equals = typeof(Object).GetMethod("Equals", 
                                        new Type[] { typeof(Object) } );
      Console.WriteLine("{0}.{1} is inherited: {2}", 
                        equals.ReflectedType.Name, equals.Name,
                        ReflectionUtilities.IsOverride(equals));
   }
}
// The example displays the following output:
//       Int32.Equals is inherited: True
//       Object.Equals is inherited: False

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