Standard function with without <T> parameter

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C#7.0

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Question 1:
I am working with system library functions that must be standard for the occasions when I have generic parameters of type <T> and those for occasions when I do not have <T> but I have a variable.

I find that, for each function I perform, I have to do two initializing functions that end up passing a System.Type parameter to the final function that standardizes.

In order not to need to do this, I would need something like what appears in "MyFunction_Alternative". but:
- It is not valid: System.Type Source_Type = (T! = Null)? T: MyVariable.GetType ();
- It is not valid: <t?>.

I would like to see <T> Nulable, because it would solve the problem.
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// Function to Employ when I have a Variable but I don't have <T>.
public static void Function_NoT_Ini(dynamic MyVariable)
{  System.Type Origen_Type = MyVariable.GetType();
   MyFunction_(Origen_Type);
}

// Function to Employ when I have <T>.
public static void Function_T_Ini<T>()
{  System.Type Origen_Type = typeof(T);
   MyFunction_(Origen_Type);
}

// Standard Final Function.
private static void MyFunction_(System.Type Origen_Type)
{   System.Console.WriteLine("The values of the Enum are:");
    foreach (int MyEnum_Value in System.Enum.GetValues(Origen_Type))
    {   System.Console.WriteLine(MyEnum_Value);
    }
}
// Alternative Final Function. It's not valid.  It is also not valid <T?>.
private static void MyFunction_Alternative<T>(dynamic MyVariable)
{   System.Type Origen_Type = (T != null) ? T : MyVariable.GetType();

    System.Console.WriteLine("The values of the Enum are:");
    foreach (int MyEnum_Value in System.Enum.GetValues(Origen_Type))
    {   System.Console.WriteLine(MyEnum_Value);
    }
}

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Question 2:
I have the problem of functions in which I need to do Cast when I don't have <T>.
Is it the right system?
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public static void MyFunction_Cast<T>(dynamic MyVariable)
{   dynamic MyValue = 10;

    // Cast with <T>.
    T MyCast_Variable = (T)MyValue;

    // Cast without <T>.
    System.Type Origen_Type = MyVariable.GetType();

    // It is not valid.
    dynamic My_Second_Variable_of_MyVariable_Type = (Origen_Type)MyValue;

    // It is valid, but is it the right system?
    dynamic My_Second_Variable_of_MyVariable_Type = System.Activator.CreateInstance(Origen_Type);

    // For example, if the type is an enumeration, it would convert the value 10 to Enumeration.MyValue10 (Not sure)
    My_Second_Variable_of_MyVariable_Type_ = MyValue;
}

What I have tried:

in all sites of internet.in all sites of internet.