Create instance of classes in loop

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I have folder that contains some classes with the same behavior (they contain one Run function that get int param and all inherit from the same class).
I need to create in loop instance from these classes and execute their function with the parameter.
That is what I started-

C#

f = GetTypesInNamespace(Assembly.GetExecutingAssembly(), "ConsoleApplication3.JJJ");
A[] a = new A[f.Count()];

for (int i = 0; i < a.Count(); a[i]=new A(), i++);
    for (int i = 0; i < a.Count(); i++)
        {
            // (a[i] as f[i].GetType()).Run(0);
        }

I don’t know how to continue, and if it's good at all…

Posted 26-Jan-14 0:33am

Member 10304617

Updated 26-Jan-14 0:38am

André Kraak

v2

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Comments

Mitchell J. 26-Jan-14 6:37am

Please clean your code sample. It's not legible.

Karthik_Mahalingam 26-Jan-14 6:47am

post your full code..

2 solutions

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

OriginalGriff · Answer 1 · 2014-01-26T00:42:00

No, if you create a new instance of class A, then you can't cast it to a derived type: that doesn't work. All you can do is cast a derived type to a type lower in teh inheritance chain, such as it's base type:

C#

public class A { }
public class AA : A { }
public class AB : A { }
public class AAA : AA { }
public class ABA : AB { }

You can cast an instance of AA or AB to A, or you can cast an instance of AAA to A or AA, and an instance of ABA to A or AB, but you can't cast an instance of A to any of the others, or of AAA to AB!

If you want to call the Run method for a derived class, then you need to create an instance of the derived class explicitly, not create an instance of the base class and try to "magically get" an instance of the derived class from that.

Vedat Ozan Oner · Answer 2 · 2014-01-26T01:18:00

You can use reflection if your classes are in an another assembly as here:
(I have created another library that contains classes, and used reflection over that library.)

C#

static void Main(string[] args)
{
    try
    {
        Assembly l = Assembly.LoadFile(@"d:\tmp\Test_ReflectionSampleLib.dll");
        var types = l.GetExportedTypes().ToList();
        var btype = types.First(t => t.Name == "Base");
        var dtypes = types.Where(t => t.BaseType == btype);
        int i = 0;
        foreach (var d in dtypes)
        {
            ConstructorInfo ci = d.GetConstructor(Type.EmptyTypes);
            MethodInfo mi = d.GetMethod("Foo");

            mi.Invoke(ci.Invoke(null), new object[] { i++ });
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex);
    }
}

Create instance of classes in loop

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