As the GenericTypeArguments property was added in .NET 4.5
Is there any way or alternative for this method in .Net 4.0
In my current project I can't use .Net version 4.5.
I want to try this technique

There's a method Type.GetGenericTypeArguments that has been available for ages. I suspect that at least in most cases, the two are equivalent. I suspect that the property is just part of the reflection API design in .NET 4.5 (to use TypeInfo etc).
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