Create class instance from string

c# reflection class instance argumentnullexception
Tim Cooper picture Tim Cooper · Feb 20, 2010 · Viewed 8.8k times · Source

I have a C# method which creates a new instance of a class from a string, however, I get an error when running the code.

obj = (ClassX)Activator.CreateInstance(Type.GetType("classPrefix_" + className));

ArgumentNullException was unhandled

Value cannot be null

Parameter name: type

Any help on this error would be appreciated.

Answer

Amal Sirisena picture Amal Sirisena · Feb 20, 2010

You may need to use the assembly qualified name as the argument to Type.GetType

eg AssemblyName.Namespace.ClassName

MSDN Doc on assembly qualified names

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