Retrieve Data in an ArrayList with C#

Question

I'm having problems retrieving data from an ArrayList collection using C#. I'm saving a class into an ArrayList. The code works in saving the data, but I don't know how to write the code to retrieve it. I thought that _serviceList [0]._displayName would retrieve the first item, but it fails. How can I view all the items in the ArrayList?

Thanks.

class Service
{
  public string _displayName;
  public ServiceControllerStatus _status;

  public Service ()
  {
    _displayName = "";
    _status = ServiceControllerStatus.Stopped;
  }

  public Service (string displayName, ServiceControllerStatus status)
  {
    _displayName = displayName;
    _status = status;
  }
}

class Program
{
  public static ArrayList _serviceList = new ArrayList ();

  public Program ()
  {
    _serviceList = null;
  }

  static void Main (string [] args)
  {
    .
    .
    .

    _serviceList.Add (new Service (service.DisplayName, service.Status));
  }

  // The following code doesn't work.
  Console.WriteLine (_serviceList [0]._displayName);

I would avoid using ArrayList in C#, period. Instead, use a generic list of something you know the type of: List<Service> services = new List<Service>(); — GEEF
– GEEF, Commented Jun 26, 2014 at 19:25
You forgot to unbox element form the list ((type of your element)mylist[0]).somePropertyofTheElement="asdf"; — ETFovac
– ETFovac, Commented Jun 26, 2014 at 19:29
Thanks @VP. Your right that List is a better choice than ArrayList. :) — jc1571
– jc1571, Commented Jun 26, 2014 at 19:46

Habib · Accepted Answer · 2014-06-26 19:24:56Z

2

If you are working on .Net framework 2.0 or higher then use List<T> a generic , type safe version for List, and just changing the line

public static ArrayList _serviceList = new ArrayList ();

To

public static List<Service> _serviceList = new List<Service>();

would solve your issue.

But, if you are working on lower framework than 2.0 then you have to explicitly cast the object to Service like:

Console.WriteLine (((Service)_serviceList [0])._displayName);

since ArrayList would return it as of type object and not Service

answered Jun 26, 2014 at 19:24

Habib

224k30 gold badges420 silver badges446 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

jc1571 Over a year ago

Thanks @Habb. That did it. I can retrieve data using: foreach (var s in _serviceList) Console.Write (s._displayName);

Collectives™ on Stack Overflow

Retrieve Data in an ArrayList with C#

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related