Ok, adding items to a listbox control is easy. You use Add method of the control. The following code shows you how to do so.
Drag a ListBox control on a form and use the following code to add items to the control.
Source Code
  1. private void Form1_Load(object sender, System.EventArgs e)
  2. {
  3. string str = "First item";
  4. int i = 23;
  5. float flt = 34.98f;
  6. listBox1.Items.Add(str);
  7. listBox1.Items.Add(i.ToString());
  8. listBox1.Items.Add(flt.ToString());
  9. listBox1.Items.Add("Last Item in the List Box");
  10. }
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