Question

I have a Winform in c# and I’m trying to build a hashtable with a list of buttons that I have. IE: Monday0700Button, Monday0730Button, Monday0800Button, and so on.
In the hashtable I am trying to order these, so that if I need to use a button, and the button that follows it, I can use the hashtable key. IE: if I need to color the background of Monday0730 and Monday 0800, I can somehow tell it to find the next key in the list.

How do I add these buttons into a hashtable so that I can use them in this capacity.
Thanks.

Answer 1

What you need is probably an OrderedDictionary, though other methods are also possible. I wouldn’t go for a Hashtable, because that’s unordered and requires quite a bit more coding to get ordering information in.

Use the following to fill an OrderedDictionary (I assumed WinForms buttons, but ASP.NET or other buttons would also work):

// I assume your buttons are created somewhere
// or already exist, i.e., they look something like:
Button MondayXXXButton = new Button();
MondayXXXButton.Name = "MondayXXXButton";
MondayXXXButton.Text = "Hello world";

OrderedDictionary buttons = new OrderedDictionary();
buttons.Add(MondayXXXButton.Name, MondayXXXButton);
// etc: for each button

Note: you can add the buttons automatically by looping through all controls.

Then, you can use the following method to find the location of the next ordered item (unfortunately, you cannot get the “next item” without looping, you’ll have to write your own ordered list if you need that):

Button GetNextButton(OrderedDictionary buttons, string searchThis)
{
    IEnumerator enumerator = buttons.Keys.GetEnumerator();

    for (enumerator.Reset(); enumerator.MoveNext(); )
        if (enumerator.Current == searchThis)
            break;

    // if false, nothing was found, or last item was found
    if (enumerator.MoveNext())
        return (Button)enumerator.Current;
    else
        return null;
}

Finally, use this to get a certain button and retrieve the next one:

Button someButton = (Button) buttons["MondayYYYButton"];
Button nextButton = GetNextButton(buttons, "MondayYYYButton");

The advantage of using an OrderedDictionary is that you shouldn’t worry about how you add the items, they’ll be ordered for you.

Update: slightly expanded explanation