Refactoring solution needed

Question

Hi, I have a page on which I must load controls dynamically based on the user selection. Let's say that I have something like this:

public static readonly Dictionary<string, string> DynamicControls = new Dictionary<string, string>
        {
            { "UserCtrl1",  "~/Controls/UserCtrl1.ascx" },
            { "UserCtrl2",  "~/Controls/UserCtrl2.ascx" },
            { "UserCtrl3",  "~/Controls/UserCtrl3.ascx" },
            { "UserCtrl4",  "~/Controls/UserCtrl4.ascx"}
};

Now let's say than on the page where the controls are loaded the code is something like this:

protected void Page_Load(object sender, EventArgs e)
        {
            SomePanel.Controls.Add(GetControl());
        }        

        private Control GetControl()
        {
            string dynamicCtrl = CurrentItem.DynamicControl;
            string path = SomeClass.DynamicControls[dynamicCtrl];

            Control ctrl = null;            

            //TODO: find a better way to load the controls
            switch (dynamicCtrl)
            {
                case "UserCtrl1":
                    {
                        ctrl = (UserCtrl1)LoadControl(path);
                    }
                    break;
                case "UserCtrl2":
                    {
                        ctrl = (UserCtrl2)LoadControl(path);
                    }
                    break;
                case "UserCtrl3":
                    {
                        ctrl = (UserCtrl3)LoadControl(path);
                    }
                    break;
                default:
                    {
                        throw new ApplicationException("Invalid dynamic control added.");
                    }                
            }

            return ctrl;
        }

The page has the required registered statements. Any idea how I can get rid of this ugly switch statement?

Answer 1

Can you not just use foreach on your dictionary and do your test and LoadControl in there?

Answer 2

That wont help because the switch is needed for casting to the right control type.

Answer 3

You don't need to cast the result from LoadControl.

This should do:

private Control GetControl()
{
    string dynamicCtrl = CurrentItem.DynamicControl;
    string path = SomeClass.DynamicControls[dynamicCtrl];

    Control ctrl = LoadControl(path);    

    return ctrl;
}

Answer 4

You probably want something like this (pseudo-ish code):

foreach key in dictionary
   if key = dynamicControl then
      ctrl = (Type.GetType(key))LoadControl(dictionary.get(key))
   end if
next