How to convert interface to right class?

Question

0.00/5 (No votes)

See more:

Hi all. I have little problem.
In first method of my code I've loaded data about students from TXT file to List<Student> collection. There are more types of students (classes PrimaryStudent, SecondaryStudent, HightSchoolStudent, UniversityStudent, ExternStudent etc...)
Now, in other method I want to save every kind of Student to different directory. My problem is in that I have all objects in one collection in that interface. How can now I differentiate or what should I do to differentiate all types of students? Please help.

Posted 5-May-12 7:02am

FrewCen

Updated 5-May-12 11:09am

Shahin Khorshidnia

v2

Add a Solution

Comments

VJ Reddy 6-May-12 3:19am

Thank you for accepting the solution.

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

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

VJ Reddy · Accepted Answer · 2012-05-05T07:40:00

There are two alternatives.

If a method or property can be introduced in the classes, then declare an abstract or virtual method or property in the Student class and override it in the derived classes to return an appropriate directory to save that class, which can be used for saving.
Check the object against the classes of Students and save to different directories accordingly as shown below.

Console.WriteLine

C#

void Main()
{
    List<Student> students = new List<Student>();
    students.Add(new PrimaryStudent());
    students.Add(new SecondaryStudent());

    //Alternative 1 If a method or property can be introduced
    //in the Derived classes
    students.ForEach(s => Console.WriteLine (s.GetDirectoryToSave()));

    //Alternative 2
    students.ForEach(s => {
        if (s is PrimaryStudent)
            Console.WriteLine (@"C:\PrimaryStudent");
        else if (s is SecondaryStudent)
            Console.WriteLine(@"C:\SecondaryStudent");

    });
}

public abstract class Student {
    public abstract string GetDirectoryToSave();

}

public class PrimaryStudent : Student {
    public override string GetDirectoryToSave(){
        return @"C:\PrimaryStudent";
    }
}
public class SecondaryStudent : Student {
    public override string GetDirectoryToSave(){
        return @"C:\SecondaryStudent";
    }
}