C# Create New T()
Take a look at new Constraint
public class MyClass<T> where T : new()
{
protected T GetObject()
{
return new T();
}
}
T
could be a class that does not have a default constructor: in this case new T()
would be an invalid statement. The new()
constraint says that T
must have a default constructor, which makes new T()
legal.
You can apply the same constraint to a generic method:
public static T GetObject<T>() where T : new()
{
return new T();
}
If you need to pass parameters:
protected T GetObject(params object[] args)
{
return (T)Activator.CreateInstance(typeof(T), args);
}
Why hasn't anyone suggested Activator.CreateInstance
?
http://msdn.microsoft.com/en-us/library/wccyzw83.aspx
T obj = (T)Activator.CreateInstance(typeof(T));
Another way is to use reflection:
protected T GetObject<T>(Type[] signature, object[] args)
{
return (T)typeof(T).GetConstructor(signature).Invoke(args);
}