Les't say I have some class with two constructors (without parameters and with them):
public class Employee
{
private int Salary = 0;
public Employee()
{
Salary = 100;
}
public Employee(int newSalary)
{
Salary = newSalary;
}
}
And I have some static helper class that have generic methods to call constructors:
public static class GenericClassCreator
{
public static T CreateClassNoParams<T>()
where T : class, new()
{
return new T();
}
public static T CreateClassWithParams<T>(params object[] args)
where T : class
{
return (T)Activator.CreateInstance(typeof(T), args);
}
}
Lets assume I have Type of class that I need to construct (typeof(Employee) in this particular case) and call it's constructor with the following code:
var method1 = typeof(GenericClassCreator).GetMethod("CreateClassNoParams");
var generic1 = method.MakeGenericMethod(typeof(Employee));
var employee1 = generic.Invoke(null, null);
var method2 = typeof(GenericClassCreator).GetMethod("CreateClassWithParams");
var generic2 = method.MakeGenericMethod(typeof(Employee));
var employee2 = generic.Invoke(null, new object[] { 500 });
Obtaining employee1 (via constructor without parameters) is ok. But obtaining employee2 (via constructor with parameter) throws exception:
Unable to cast object of type System.Int32 to System.Object[] Even if I change
generic.Invoke(null, new object[] { 500 });
to
generic.Invoke(null, new object[] { new object() });
exception is thrown
Unable to cast object of type System.Object to System.Object[]
So what's wrong with my code?
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