Activators Dotnet 4.6.1 -
Please be very careful. Most searches for "activators" target cracked software or keygens for older versions of .NET frameworks or tools like Visual Studio.
The Safe Solution: Download the official .NET 4.6.1 runtime or developer pack directly from Microsoft:
If your assembly is not loaded yet:
ObjectHandle handle = Activator.CreateInstanceFrom("MyLibrary.dll", "MyNamespace.MyClass");
object instance = handle.Unwrap();
| Constraint | Behavior |
|------------|----------|
| Abstract types | Throws MissingMethodException (no constructor). |
| Interface types | Throws MissingMethodException. |
| Value types | Works (returns zero-initialized struct). |
| No public parameterless constructor | Throws MissingMethodException (unless arguments provided). |
| Static class | Throws TypeInitializationException / MissingMethodException. |
| Generic type definitions | Not allowed (must be closed generic). |
| Security restrictions | Demands ReflectionPermission or equivalent. |
Activator.CreateInstance(Type) throws a MissingMethodException if no public parameterless constructor exists. activators dotnet 4.6.1
Fix: Use Activator.CreateInstance(Type, object[]) with matching arguments, or ensure a default constructor exists.
Binary or XML serialization often uses activators under the hood to reconstruct objects. Please be very careful
| Method | Description |
|--------|-------------|
| CreateInstance(Type) | Creates an instance of the specified type using its parameterless constructor. |
| CreateInstance(Type, object[]) | Creates an instance using the constructor that best matches the specified arguments. |
| CreateInstance<T>() | Generic version; creates an instance of T using the parameterless constructor (requires new() constraint). |
| CreateInstanceFrom(string assemblyFile, string typeName) | Loads an assembly file and creates an instance of the named type. |
| GetObject(Type) | Creates an instance of a COM object (remoting scenario). |
Note: .NET 4.6.1 does not include
ActivatorUtilities(that came with .NET Core / later .NET). The Safe Solution: Download the official
| Mechanism | Speed | Flexibility | Type safety |
|-----------|-------|-------------|--------------|
| new | Fastest | None | Compile-time |
| Activator.CreateInstance | Slow | High (late binding) | Runtime cast required |
| ConstructorInfo.Invoke | Slightly slower than Activator | Very high | Runtime |
| Compiled Expression lambdas | Near new | High | Runtime |
| FormatterServices.GetUninitializedObject | Fastest but dangerous | None (no constructor called) | None |
Recommendation: Use Activator for simplicity in low-frequency operations (e.g., app startup, plugin loading). For tight loops, use compiled delegates.
