Having a button increment an array each time it is clicked

Question

I'm tasked with having a button that will set a value entered to an array. The user will enter a value press the button, once the button is pressed the value the user entered is stored into an array. My teacher (yes this is a homework question) said that he wants it to do only one value at a time.

The problem i'm running into is, I just don't know what to write in order for this to happen. I've tried looking at what all I can do in the event but that has gotten me nowhere, unless the answer was there and I just completely missed it.

Any suggestions on where to look, or an idea of what to write would be awesome.

private void addToArray_Click(object sender, EventArgs e)
{
    Button bclick = (Button) sender;

    string variables = addArrayTextBox.Text;
    int []vars = new int[5];
    vars = parseVariableString(variables);
    int numberIndex = 0;

    for (int i = 0; i < vars.Length; i++)
    {
        int indexNumber = vars.Length;
        numberIndex = indexNumber;
    }
    integerTextBox.Text = numberIndex.ToString();
}

Is what I currently have typed up.

Answer 1

to get you started

let's get the graphical designer stuff out of the way first:

1. make your winforms project
2. drag and drop a button
3. drag and drop a text box
4. double-click on the button to create a button_click event handler

next, you'll probably want your array to stay in scope, the simplest way to do that is to declare it as a field of your Form1 instance, and then instantiate and/or initialize it in the `Form1 Constructor.

Then you can access it from your event handler

example:

public partial class Form1 : Form
{
    int[] vars;
    int intergersEntered;
    public Form1()
    {
        InitializeComponent();

        vars = new int[5];
        intergersEntered = 0;
        // insert other initialization here
    }

    private void button1_Click(object sender, EventArgs e)
    {
       vars[0] = int.Parse(textBox1.Text);
       intergersEntered++;
       textBox2.Text = intergersEntered.ToString();
    }
...

Answer 2

I'm not sure I get your question based on your code. Paraphrasing, you want to increase an array length by 1 when a button is pressed, yes?

public partial class Form1 : Form
{
    private int[] vars;

    public Form1()
    {
        InitializeComponent();
        vars = new int[5];
    }

    private void button1_Click(object sender, EventArgs e)
    {
        int[] tmp = new int[vars.Length + 1];
        vars.CopyTo(tmp, 0);
        vars = tmp;
    }
}

Answer 3

It seems to me that you need to just resize the array to one higher each time the "Add To Array" button is clicked:

private void addToArray_Click(object sender, EventArgs e)
{

    //Calculate the new size of the array
    int newLength = arrayOfIntegers.Length + 1;

    //Resize the array
    Array.Resize(ref arrayOfIntegers, newLength);

    //Add the new value to the array
    //Note that this will fail if the textbox does not contain a valid integer.  
    //You can use the Integer.TryParse method to handle this
    arrayOfIntegers[newLength] = Integer.Parse(addArrayTextBox.Text);  

    //Update the text box with the new count
    integerTextBox.Text = newLength.ToString();
}