List Box Example Program Add Remove Clear Items

List Box Example Program Add Remove Clear Items –

ListBox and Its Important Methods Used In this Windows Forms Application

In C#, a ListBox is a commonly used graphical control element that displays a list of items from which the user can select one or more. The ListBox class provides several methods to manipulate the items within it. Here’s an explanation of the `Add`, `Remove`, `RemoveAt`, and `Clear` methods of the ListBox class:

1. Add Method

The `Add` method is used to add an item to the ListBox. You can add items as strings, objects, or any other data type that can be represented as a string.

listBox1.Items.Add(“Item 1”); // Adding a string item
listBox1.Items.Add(42); // Adding an integer item

2. Remove Method

The `Remove` method is used to remove a specific item from the ListBox based on its value. It searches for the first occurrence of the specified item and removes it.

listBox1.Items.Remove(“Item 1”); // Removes the first occurrence of “Item 1”
listBox1.Items.Remove(42); // Removes the first occurrence of the integer 42

If the item is not found in the ListBox, nothing happens (no exception is thrown).

3. RemoveAt Method

The `RemoveAt` method is used to remove an item at a specific index in the ListBox. The index is zero-based, meaning the first item is at index 0, the second item at index 1, and so on.

listBox1.Items.RemoveAt(0); // Removes the first item in the ListBox
listBox1.Items.RemoveAt(2); // Removes the third item in the ListBox

If the index is out of the valid range of indices for the ListBox, an `ArgumentOutOfRangeException` exception is thrown.

4. Clear Method

The `Clear` method is used to remove all items from the ListBox.

listBox1.Items.Clear(); // Removes all items from the ListBox

Source Code


using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace ListBox1
{
 public partial class Form1 : Form
 {
 public Form1()
 {
 InitializeComponent();
 }
 private void button1_Click(object sender, EventArgs e)
 {
 listBox1.Items.Add(textBox1.Text);
 }
 private void button2_Click(object sender, EventArgs e)
 {
 listBox1.Items.Remove(textBox1.Text);
 }
 private void button5_Click(object sender, EventArgs e)
 {
 int i;
 i = int.Parse(textBox1.Text);
 listBox1.Items.RemoveAt(i);
 }
 private void button3_Click(object sender, EventArgs e)
 {
 listBox1.Items.Clear();
 }
 private void button4_Click(object sender, EventArgs e)
 {
 this.Close();
 }
}
}