DefineType Method (String, TypeAttributes, Type)

ModuleBuilder.DefineType Method (String, TypeAttributes, Type)


Constructs a TypeBuilder given type name, its attributes, and the type that the defined type extends.

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

public TypeBuilder DefineType(
	string name,
	TypeAttributes attr,
	Type parent


Type: System.String

The full path of the type. name cannot contain embedded nulls.

Type: System.Reflection.TypeAttributes

The attribute to be associated with the type.

Type: System.Type

The type that the defined type extends.

Return Value

Type: System.Reflection.Emit.TypeBuilder

A TypeBuilder created with all of the requested attributes.

Exception Condition

A type with the given name exists in the parent assembly of this module.


Nested type attributes are set on a type that is not nested.


name is null.

Type names must be unique within an assembly. You cannot have two types with the same name in two different modules of an assembly.


Starting with the .NET Framework 2.0 Service Pack 1, this member no longer requires ReflectionPermission with the ReflectionPermissionFlag.ReflectionEmit flag. (See Security Issues in Reflection Emit.) To use this functionality, your application should target the .NET Framework 3.5 or later.

The following example creates a TypeBuilder in the current dynamic module using CreateType, builds and completes the type, and saves the assembly.

AssemblyName asmname = new AssemblyName();
asmname.Name = "assemfilename.exe";        
AssemblyBuilder asmbuild = System.Threading.Thread.GetDomain().
            DefineDynamicAssembly(asmname, AssemblyBuilderAccess.RunAndSave);
ModuleBuilder modbuild = asmbuild.DefineDynamicModule( "modulename",
   "assemfilename.exe" );
TypeBuilder typebuild1 = modbuild.DefineType( "typename" );
asmbuild.Save( "assemfilename.exe" );

.NET Framework
Available since 1.1
Available since 2.0
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