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Posted 31 Jan 2012

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Alternative to Activator.CreateInstance

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1.00/5 (2 votes)
31 Jan 2012CPOL
I've tried a few different ways to dynamically create an object of 'unknown' type.This is my final, simple result: public static T Create() { Type type = typeof(T); return (T)type.Assembly.CreateInstance(type.FullName); ...
I've tried a few different ways to dynamically create an object of 'unknown' type.

This is my final, simple result:


C#
        public static T Create<T>()
        {
            Type type = typeof(T);
            return (T)type.Assembly.CreateInstance(type.FullName);
        }
</t>



Ok, I'm getting a little flak here.
This is just a simple example.

In my project I deal with a lot of data objects, not all know at compile time, as some classes / objects may be from other separate (dynamically loaded) assemblies, yet still within the AppDomain.
A similar implementation of the code above allows my worker class to dynamically create any data object, and populate it.
As far as code-costs go, this is a very light simple method. I'm still yet to check CPU-costs.
If anybody has reliable stats on CPU costs please let me know.

C#
private static T From<T>(IDataReader reader, Type type)
{
    dynamic obj = type.Assembly.CreateInstance(type.FullName);
    ...
    return obj;
}


This code did / does not work for me as the compiler moans about the "new" keyword for the template "T".
C#
object obj = new T();

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

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About the Author

Jonathan Jandrell
Web Developer
South Africa South Africa
C# Developer

Comments and Discussions

 
GeneralReason for my vote of 1 Reason for my vote of one: if you kn... Pin
OriginalGriff31-Jan-12 9:30
mveOriginalGriff31-Jan-12 9:30 
GeneralReason for my vote of 1 Unfortunately the problem with this ... Pin
Dean Oliver31-Jan-12 6:52
MemberDean Oliver31-Jan-12 6:52 
Reason for my vote of 1
Unfortunately the problem with this is it's not a solution sure it works. but what if you only know the type at run-time then how you going to use your create Method. you basically using a fancy way to call new Example(); Not to mention the fact it is virtually the same as Activator.CreateInstance. not an alternative. Did you even try to test the performance differences between all the implementations?

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