TypeBuilder.DefineDefaultConstructor(MethodAttributes) Method

Reference

Definition

Namespace:: System.Reflection.Emit

Assembly:: System.Reflection.Emit.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Source:: TypeBuilder.cs

Source:: TypeBuilder.cs

Source:: TypeBuilder.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

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

public:
 System::Reflection::Emit::ConstructorBuilder ^ DefineDefaultConstructor(System::Reflection::MethodAttributes attributes);

public System.Reflection.Emit.ConstructorBuilder DefineDefaultConstructor (System.Reflection.MethodAttributes attributes);

[System.Runtime.InteropServices.ComVisible(true)]
public System.Reflection.Emit.ConstructorBuilder DefineDefaultConstructor (System.Reflection.MethodAttributes attributes);

member this.DefineDefaultConstructor : System.Reflection.MethodAttributes -> System.Reflection.Emit.ConstructorBuilder

[<System.Runtime.InteropServices.ComVisible(true)>]
member this.DefineDefaultConstructor : System.Reflection.MethodAttributes -> System.Reflection.Emit.ConstructorBuilder

Public Function DefineDefaultConstructor (attributes As MethodAttributes) As ConstructorBuilder

Parameters

attributes: MethodAttributes

A MethodAttributes object representing the attributes to be applied to the constructor.

Returns

ConstructorBuilder

Returns the constructor.

Attributes: ComVisibleAttribute

Exceptions

NotSupportedException

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

InvalidOperationException

The type was previously created using CreateType().

-or-

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

Examples

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.
array<Type^>^ constructorArgs = {String::typeid};
ConstructorBuilder^ myConstructorBuilder =
   helloWorldTypeBuilder->DefineConstructor( MethodAttributes::Public,
      CallingConventions::Standard, constructorArgs );
// Generate IL for the method. The constructor stores its argument in the private field.
ILGenerator^ myConstructorIL = myConstructorBuilder->GetILGenerator();
myConstructorIL->Emit( OpCodes::Ldarg_0 );
myConstructorIL->Emit( OpCodes::Ldarg_1 );
myConstructorIL->Emit( OpCodes::Stfld, myGreetingField );
myConstructorIL->Emit( OpCodes::Ret );

// Define the constructor.
Type[] constructorArgs = { typeof(String) };
ConstructorBuilder myConstructorBuilder =
   helloWorldTypeBuilder.DefineConstructor(MethodAttributes.Public,
                      CallingConventions.Standard, constructorArgs);
// Generate IL for the method. The constructor stores its argument in the private field.
ILGenerator myConstructorIL = myConstructorBuilder.GetILGenerator();
myConstructorIL.Emit(OpCodes.Ldarg_0);
myConstructorIL.Emit(OpCodes.Ldarg_1);
myConstructorIL.Emit(OpCodes.Stfld, myGreetingField);
myConstructorIL.Emit(OpCodes.Ret);

' 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.Ldarg_0)
myConstructorIL.Emit(OpCodes.Ldarg_1)
myConstructorIL.Emit(OpCodes.Stfld, myGreetingField)
myConstructorIL.Emit(OpCodes.Ret)

Remarks

Because the parameterless 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 parameterless constructor that simply calls the base class constructor.
You want to set the attributes on the parameterless constructor to something other than PrivateScope, Public, HideBySig, SpecialName, and RTSpecialName.

Applies to