Question

I want to customize a object’s behavior before the object is created. I think maybe add some hooks in the object constructor and do the change there would be a choice. Is there any way to do so in .net? Thanks a lot in advance!

EDIT:

Here is a example:

Assume we have a class Kid which use Perform method to get credit in the class.

public class Kid
{
    public void Perform() { ... }
}

And the School conduct to lectures:

public class School
{
    public void Chemistry() {
        // The school have a good chemistry teacher, so every kid study well
        // Kid.Perform() is modified to reflect that 
        Kid tom = new Kid();
        tom.Perform();
    }

    public void Biology() {
        //This class is boring, everyone will nap in 5~10 min
        // Kid.Perform() use a random number to simulate how 
        //long this kid can hold it.
        Kid tom = new Kid(); tom.Perform();
        Kid jerry = new Kid(); jerry.Perform();
    }
}

We want every kid perform in the same way and I do not want:

1. Change class Kid because it is generated from a 3rd party tool and widely used somewhere else.
2. Use inheritance.

Answer 1

In your case you would have to add your logic after calling the constructor. You could write a factory method which does this; replacing new SpecialObject() with MyExtendedSpecialObject.Create() shouldn’t be too difficult.

public static class MyExtendedSpecialObject
{
    public static SpecialObject Create()
    {
        var newObject = new SpecialObject();

        // Do something with newObject

        return newObject;
    }
}