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POIn C#, how to instantiate a passed generic type inside a method?
 

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  1. POIn C#, how to instantiate a passed generic type inside a method?
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    <p>How can I instantiate the type T inside my <code>InstantiateType&lt;T&gt;</code> method below?</p> <p>I'm getting the error: <strong>'T' is a 'type parameter' but is used like a 'variable'.</strong>:</p> <h2>(SCROLL DOWN FOR REFACTORED ANSWER)</h2> <pre><code>using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TestGeneric33 { class Program { static void Main(string[] args) { Container container = new Container(); Console.WriteLine(container.InstantiateType&lt;Customer&gt;("Jim", "Smith")); Console.WriteLine(container.InstantiateType&lt;Employee&gt;("Joe", "Thompson")); Console.ReadLine(); } } public class Container { public T InstantiateType&lt;T&gt;(string firstName, string lastName) where T : IPerson { T obj = T(); obj.FirstName(firstName); obj.LastName(lastName); return obj; } } public interface IPerson { string FirstName { get; set; } string LastName { get; set; } } public class Customer : IPerson { public string FirstName { get; set; } public string LastName { get; set; } public string Company { get; set; } } public class Employee : IPerson { public string FirstName { get; set; } public string LastName { get; set; } public int EmployeeNumber { get; set; } } } </code></pre> <h2>REFACTORED ANSWER:</h2> <p>Thanks for all the comments, they got me on the right track, this is what I wanted to do:</p> <pre><code>using System; namespace TestGeneric33 { class Program { static void Main(string[] args) { Container container = new Container(); Customer customer1 = container.InstantiateType&lt;Customer&gt;("Jim", "Smith"); Employee employee1 = container.InstantiateType&lt;Employee&gt;("Joe", "Thompson"); Console.WriteLine(PersonDisplayer.SimpleDisplay(customer1)); Console.WriteLine(PersonDisplayer.SimpleDisplay(employee1)); Console.ReadLine(); } } public class Container { public T InstantiateType&lt;T&gt;(string firstName, string lastName) where T : IPerson, new() { T obj = new T(); obj.FirstName = firstName; obj.LastName = lastName; return obj; } } public interface IPerson { string FirstName { get; set; } string LastName { get; set; } } public class PersonDisplayer { private IPerson _person; public PersonDisplayer(IPerson person) { _person = person; } public string SimpleDisplay() { return String.Format("{1}, {0}", _person.FirstName, _person.LastName); } public static string SimpleDisplay(IPerson person) { PersonDisplayer personDisplayer = new PersonDisplayer(person); return personDisplayer.SimpleDisplay(); } } public class Customer : IPerson { public string FirstName { get; set; } public string LastName { get; set; } public string Company { get; set; } } public class Employee : IPerson { public string FirstName { get; set; } public string LastName { get; set; } public int EmployeeNumber { get; set; } } } </code></pre>
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    1. USEdward Tanguay
    1. USEdward Tanguay
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    1. CO+1 for shifting to a better design pattern.
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      1. POIn C#, how to instantiate a passed generic type inside a method?
      1. USJoel Coehoorn
    2. CO+1 for extremely neatly typed code, a rarity.
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      1. USnawfal
 

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