Label update - C# Discussion Boards

30-Jan-07 1:06

Hi
In my 'virtual roulette' table I need to increment the amount of times each random number has occured for any given amount of spins of the wheel. Each label (0-36) has another blank label next to it that will contain these occurances.

If for 3 spins the random numbers are 3,14 and 17. Blank labels 3,14 and 17 should now have the value 1.

Instead of typing IF RanNum = 1 the add 1 to lab1
IF RanNum = 2 the add 1 to lab2
IF RanNum = 3 the add 1 to lab3 etc.............

How do I use.....

STRING labNum = "lab" + RanNum

to then access the corresponding Label on the page?

FindControl is looking good but does that not just tell me if it is there or not?

Any help for this newbie would be great.

Harvey

Martin#30-Jan-07 1:19

30-Jan-07 1:19

Hello,

You could hold the instances in a Hashtable and use the number as a the key.

All the best,

Martin

imnotso#30-Jan-07 1:21

30-Jan-07 1:21

Thought of that or an Array, what if I had a million spins though, how many instances can I have?

Thanks for the quick reply

Martin#30-Jan-07 1:26

Re: Label update [modified]

30-Jan-07 1:26

imnotso# wrote:
Thought of that or an Array, what if I had a million spins though, how many instances can I have?

What has the numbr of spinns todo with the number of labels?

I would think, that there only are your 32*2 instances, which are always hold in the hashtable.
Or have I missed something?

All the best,

Martin

Pete O'Hanlon30-Jan-07 2:05

Pete O'Hanlon

30-Jan-07 2:05

You will still only have one hashtable (or array). This would be created once, and you would only be incrementing values in it. Here's a sample for an ArrayList:

private ArrayList _list;

public void SetupArray(int maxRows)
{
  _list = new ArrayList();
  for (int i = 0; i < maxRows; i++)
  {
    _list.Add(0);
  }
}

public void RoleDice()
{
  int val = ValueFromDiceRole();

  Convert.ToInt64(_list[val])++;
}

Now, go ahead and call RoleDice one million times. Call it 10 million. The memory footprint won't go up that much.

-- modified at 8:20 Tuesday 30th January, 2007

Luc Pattyn30-Jan-07 2:05

Luc Pattyn

30-Jan-07 2:05

Construct an array that keeps your 37 labels in numerical order, whatever their names are.

Smile | :)

Luc Pattyn

imnotso#30-Jan-07 2:12

30-Jan-07 2:12

Would I then still not have to move the values from the array or table one by one (ie 37 times) to the labes on the screen?

I thought there might be some way of using a contructed STRING (Lab + RandonNumber) and then attach that to the corresponding Label on the screen using some function I don't know about !!

Cheers for the replies so far.

Martin#30-Jan-07 2:20

30-Jan-07 2:20

imnotso# wrote:
Would I then still not have to move the values from the array or table one by one (ie 37 times) to the labes on the screen?

Ohhhh, here is the misunderstanding!!!!

in youre array or hashtable you hold just the reference to the lables on the form. So if you change a property in your Hashtablelabel[x].Text it will be shown also in the Form.

Hope that helps.

All the best,

Martin

imnotso#30-Jan-07 2:42

30-Jan-07 2:42

It does help, thanks Martin. Good on ya.

Martin#30-Jan-07 2:55

30-Jan-07 2:55

Ok,
I just whant to get you a little more help, to make your code alittle more dynamic.

What I would do, is to create my one labelclass which inherits from System.Windows.Forms.Label.
This class has just one member per default: Number (which is integer).
Like this:

using System;
using System.ComponentModel;
using System.Collections;
using System.Diagnostics;

namespace WindowsApplication1
{
	public class CasinoLabel : System.Windows.Forms.Label
	{
		private System.ComponentModel.Container components = null;

		public CasinoLabel()
		{
			InitializeComponent();
		}

		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if(components != null)
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		private void InitializeComponent()
		{
			components = new System.ComponentModel.Container();
		}

		private int _number;
		[Browsable(true), Category("Casino")]
		public int Number
		{
			get
			{
				return _number;
			}
			set
			{
				_number = value;
			}
		}
	}
}

Now you can do much more fancy stuff with this class (I'm sure you will have a lot of ideas.)

Than place your new labels on your Form and set the Number Property over the designer.

In the Forms constructor you just have to search for your special Labels now and add them to a hashtable.
Like this:

private Hashtable CasinoLabels = new Hashtable();

public Form1()
{
    InitializeComponent();

    foreach(Control c in this.Controls)
    {
        CasinoLabel actlabel = c as CasinoLabel;
        if(actlabel != null)
        {
            CasinoLabels.Add(actlabel.Number, actlabel);
        }
    }
}

If you then whant to set youre text property over a random number just do this:

CasinoLabel randomLabel = CasinoLabels[randomnumber] as CasinoLabel;
randomLabel.Text = "1";

I just wanted to play around a little! Wink | ;)

All the best,

Martin

imnotso#30-Jan-07 4:00

30-Jan-07 4:00

Top notch stuff Martin, thanks.

Martin#30-Jan-07 4:05

Re: Label update [modified]

30-Jan-07 4:05

Luc Pattyn30-Jan-07 2:42

Luc Pattyn

30-Jan-07 2:42

Labels are reference types, putting an existing label in an array (or some other collection)
is just an administrative operation, it does not change your label, nor does it create
a new one. It does provide a structured way to access one or more labels afterwards, as in:

Label[] myLabels=new Label[37];  // creates an array capable of holding 37 labels
for (int i=0; i<=36; i++) {
    Label label=new Label();     // creates a new label
    label.Text="number "+i;
    myForm.Controls.Add(label);  // add label to form
    myLabels[i]=label;           // and add same label to array
}
// now use the array to modify one label:
myLabels[7].Text="I was here";   // the 7th label gets a new text !

This snippet shows run-time actions to create labels and to add them to the form.
It does not include the code to take care of size, font, and location !
You could add these at will.

Smile | :)

-- modified at 9:02 Tuesday 30th January, 2007

Luc Pattyn

Re: Label update [modified]

Jasmine250130-Jan-07 5:53

Jasmine2501

30-Jan-07 5:53

The way this is usually done is to create an array of 37 ints... one for each number 0 to 36. Then in each cell of the array, you store the number of times that spot has been hit.

There are many ways to display the reports after each spin. I would say, just keep your 37 controls in an array, and match up the values. So, after a roll, you would have something like this:

<br />
//spot is the number we rolled...<br />
hits[spot]++; //hits is the array of integers<br />
labels[spot].Text = rolls[spot].ToString(); //labels is an array of Labels<br />

There's some much more elegant solutions to this, but this is pretty straightforward.

"Quality Software since 1983!"
http://www.smoothjazzy.com/ - see the "Programming" section for freeware tools and articles.

imnotso#30-Jan-07 6:13

30-Jan-07 6:13

I've eventually worked out how to hold the values in an array for any given amount of spins. The next part would be to get these values onto the page.

Do I need to have the labels in a Array as you suggest? Can't I now match the existing lables lb0,lb1,lb2lb3 etc on the screen to my new 0-36 array (arHitArray) with the 'hits' as values in?

sort of .....

for (int a=0; a < 37; a++)
{
lb(n).text = arHitArrary(n).value
}

otherwise it's just ........

lb0.Text = arNumArray[0].ToString();
lb1.Text = arNumArray[1].ToString();
lb2.Text = arNumArray[2].ToString();
lb3.Text = arNumArray[3].ToString();

which is ok but not very cool.

Thanks for so far though

-- modified at 12:28 Tuesday 30th January, 2007

Dan Neely30-Jan-07 6:45

Dan Neely

30-Jan-07 6:45

You can do the former using reflection, but it makes the code significantly more complex and error prone since a typo won't be found at compile time. An array of labels is by far the easier solution.

--
Rules of thumb should not be taken for the whole hand.

Jasmine250130-Jan-07 18:34

Jasmine2501

30-Jan-07 18:34

Is this for a web application or what?

There's a lot of questions here, but the overall application should be extremely simple. No reflection or any of that junk needs to be done here, it's a simple roulette application. Using a bunch of Label controls for the UI isn't the best option, but it's viable.

Anyway, at the beginning of the program, you put all the Labels into one array and you create an array of integers to match. Probably just do this with 37 lines of code, that way, you can rename things later if you want, and you aren't depending on some majick naming scheme to make your app work.

Now, ideally, you are only going to represent one roulette spin each time... so you only have to update one Label and one integer each time... the one you hit. Follow me now? No loops or anything, just a simple event handler that generates your random number and updates a single element of the interface, and a single element of the integer array. C# is strongly typed, so you'll have to convert your int to string...

<br />
int num = (some random number);<br />
spots[num]++;<br />
(labels[num]).Text = spots[num].ToString();<br />

So your initialization is tricky, but then your operational phase is elegant and simple. This is ok as long as it enables a straightforward approach. Think about this in terms of M-V-C...

http://en.wikipedia.org/wiki/Model-view-controller[^]

M = array of integers representing the history of spins (you could also add other simple elements, like maybe a single integer representing the most recent roll)
V = array of Labels (and all the built-in crap that makes them work)
C = Buttons and such on the interface, and your event-handler function

"Quality Software since 1983!"
http://www.smoothjazzy.com/ - see the "Programming" section for freeware tools and articles.