Question

I have 6 text boxes in 6 lines, 36 in all. Line one, box one is called L1N1, line one, box two is L1N2 etc. I want to dynamically assign values to these text boxes using a string…can this be done in C#? E.g.

    private void Generate_Click(object sender, EventArgs e)
    {
        int[,] numbers = new int[6, 6];
        int lin = 0;
        while (lin < 6)
        {
            lin++;
            int num = 0;
            while (num < 6)
            {
                num++;
                Random random = new Random();
                int randomNum = random.Next(1, 45);
                "L" + lin + "N" + num /* <--here is my string (L1N1) i want to 
                                          set my textbox(L1N1).text to a value
                                          randomNum!*/

Answer 1

I echo Jon Skeet’s sentiments. If you want to be able to locate a control by some row/column system, the easiest way to do so is to put the controls themselves into a collection that allows them to be indexed in a similar way:

var textboxes = new TextBox[6][];
textboxes[0] = new TextBox[]{txtL1N1, txtL1N2, txtL1N3, txtL1N4, txtL1N5, txtL1N6};
//create the rest of the "lines" of TextBoxes similarly.

//now you can reference the TextBox at Line X, number Y like this:
textboxes[X-1][Y-1].Text = randomNum.ToString();

Now, if you REALLY wanted to access these textboxes by some string value, you would use the Tag property, which is a general-purpose property of most Controls. You could also name all your textboxes according to some system. Then, a little Linq can get you the textbox you want:

this.Controls.OfType<TextBox>()
   .Single(t=>t.Tag.ToString() == "L1N1").Text = randomNum.ToString();

However, understand this will be VERY slow; you’ll be searching the full collection of all controls that exist on the Form every time you want one. Indexing will be much faster.