Question

I just designed a simple “For Loop” using window form application. I would like that this will be only clickable once & that it will not repeat the same information if I click the button. How could I do that? thanks
Here is my code:

        int count;

        for (count = 0; count < 5; count = count + 1)
        {
            listBox1.Items.Add("This is count: " + count);
        }
        const string textEnd = "Done!!!";
        {
            listBox1.Items.Add(textEnd);
        }

==== Additional Info ===
I’ve made it this way now. This will only click once, but the button is still enable. I think this is ok:

        int count;

        for (count = 0; count < 5; count++)
        {
            string newItem = "This is count: " + count; 
            if (listBox1.Items.IndexOf(newItem) < 0) 
            { 
                listBox1.Items.Add(newItem); 
            }
         }

        const string textEnd = "Done!!!";
        if (listBox1.Items.IndexOf(textEnd) <0)
        {
            listBox1.Items.Add(textEnd);
        }

Answer 1

I’m assuming you don’t want the same items added to the list multiple times?

Instead of

{
    listBox1.Items.Add("This is count: " + count);
}

You need something like

{
    string newItem = "This is count: " + count;
    if(listBox1.Items.IndexOf(newItem) < 0)
    {
        listBox1.Items.Add(newItem);
    }
}