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TypeBuilder.DefineDefaultConstructor Method

Defines the default constructor. The constructor defined here will simply call the default constructor of the parent.

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

<ComVisibleAttribute(True)> _
Public Function DefineDefaultConstructor ( _
	attributes As MethodAttributes _
) As ConstructorBuilder


Type: System.Reflection.MethodAttributes
A MethodAttributes object representing the attributes to be applied to the constructor.

Return Value

Type: System.Reflection.Emit.ConstructorBuilder
Returns the constructor.


The parent type (base type) does not have a default constructor.


The type was previously created using CreateType.


For the current dynamic type, the IsGenericType property is true, but the IsGenericTypeDefinition property is false.

Because the default constructor is automatically defined, it is necessary to call this method only in the following situations:

  • You have defined another constructor and you also want a default constructor that simply calls the base class constructor.

  • You want to set the attributes on the default constructor to something other than PrivateScope, Public, HideBySig, SpecialName, and RTSpecialName.

The following code sample demonstrates the use of DefineConstructor to set a constructor's particular signature and attributes on a dynamic type and return a corresponding ConstructorBuilder for MSIL population.

' Define the constructor.
Dim constructorArgs As Type() = {GetType(String)}
Dim myConstructorBuilder As ConstructorBuilder = helloWorldTypeBuilder.DefineConstructor _
                     (MethodAttributes.Public, CallingConventions.Standard, constructorArgs)
' Generate IL for the method.The constructor stores its argument in the private field.
Dim myConstructorIL As ILGenerator = myConstructorBuilder.GetILGenerator()
myConstructorIL.Emit(OpCodes.Stfld, myGreetingField)

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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