C# listbox exception

Question

hi, if i remove an item from index 2 inn listbox and there is no item at index 2 i. e. only 2 item in listbox in index 0 and 1.then there is an exception.how handle it.

Rajneesh Rai · Answer

Hi Arun, yes,if you try to remove item at index 2 (that does not exists)of listbox, you would get exception ArgumentOutOfRangeException. So keep item removal code in try catch block.. and check that the index exists or not in listbox i.e. int index = index to remove; if (index lb.Items.RemoveAt(index);

Satyapriya Nayak · Answer

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; namespace WindowsFormsApplication7 { public partial class Form3 : Form { public Form3() { InitializeComponent(); } private void Form3_Load(object sender, EventArgs e) { listBox1.Items.Add("a"); listBox1.Items.Add("a"); listBox1.Items.Add("c"); } private void button1_Click(object sender, EventArgs e) { if (listBox1.SelectedIndex != -1) { int i = 0; i = listBox1.SelectedIndex; listBox1.Items.RemoveAt(i); } } } }

Vulpes · Answer

If no item is selected in a ListBox, then its SelectedIndex property is equal to -1. So, if the value of this property is not -1, it means that an item must be selected.

Arun Kurmi · Answer

Thanks,It is working but what are the meaning of this line: if (listBox1.SelectedIndex != -1)

C# listbox exception

Answers (4)