C# – Create object instance without invoking constructor

In C#, is there a way to instantiate an instance of a class without invoking its constructor?

Assume the class is public and is defined in a 3rd party library and the constructor is internal. The reasons I want to do this are complicated but it would be helpful to know if it's possible using some kind of C# hackery.

NOTE: I specifically do not want to call any constructor so using reflection to access the internal constructor is not an option.

Best Answer

I have not tried this, but there is a method called FormatterServices.GetUninitializedObject that is used during deserialization.

Remarks from MSDN says:

Because the new instance of the object is initialized to zero and no constructors are run, the object might not represent a state that is regarded as valid by that object.

Related Solutions

C# – How to create a new object instance from a Type

The Activator class within the root System namespace is pretty powerful.

There are a lot of overloads for passing parameters to the constructor and such. Check out the documentation at:

http://msdn.microsoft.com/en-us/library/system.activator.createinstance.aspx

or (new path)

https://docs.microsoft.com/en-us/dotnet/api/system.activator.createinstance

Here are some simple examples:

ObjectType instance = (ObjectType)Activator.CreateInstance(objectType);

ObjectType instance = (ObjectType)Activator.CreateInstance("MyAssembly","MyNamespace.ObjectType");

C# – Calling the base constructor in C#

Modify your constructor to the following so that it calls the base class constructor properly:

public class MyExceptionClass : Exception
{
    public MyExceptionClass(string message, string extrainfo) : base(message)
    {
        //other stuff here
    }
}

Note that a constructor is not something that you can call anytime within a method. That's the reason you're getting errors in your call in the constructor body.

Best Answer

Related Solutions

C# – How to create a new object instance from a Type

C# – Calling the base constructor in C#

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