Adjust combo box drop down list width to longest string width

private void AdjustWidthComboBox_DropDown(object sender, System.EventArgs e)
{
    ComboBox senderComboBox = (ComboBox)sender;
    int width = senderComboBox.DropDownWidth;
    Graphics g = senderComboBox.CreateGraphics();
    Font font = senderComboBox.Font;
    int vertScrollBarWidth =
        (senderComboBox.Items.Count > senderComboBox.MaxDropDownItems)
        ? SystemInformation.VerticalScrollBarWidth : 0;
 
    int newWidth;
    foreach (object item in ((ComboBox)sender).Items)
    {
        // instead of treating an item as a string, treat it as an object and use GetItemText to fetch the item's textvalue
        string s = senderComboBox.GetItemText(item);
        newWidth = (int)g.MeasureString(s, font).Width
            + vertScrollBarWidth;
        if (width < newWidth)
        {
            width = newWidth;
        }
    }
    senderComboBox.DropDownWidth = width;
}

using System;
using System.Linq;
using System.Windows.Forms;
 
namespace MyNamespace
{
    public static class ExtensionMethods
    {
        /// <summary>
        /// Autosizes the width of the size drop down.
        /// </summary>
        /// <param name="sender">The sender.</param>
        public static void AutoSizeDropDownWidth(this ComboBox sender)
        {
            if (sender.Items.Count == 0)
            {
                sender.DropDownWidth = sender.Width;
                return;
            }
            
            var comboBoxItems = new object[sender.Items.Count];
            sender.Items.CopyTo(comboBoxItems, 0);
 
            using (var graphics = sender.CreateGraphics())
            {
                var largestItem = (from width in
                                       (from item in comboBoxItems
                                        select Convert.ToInt32(graphics.MeasureString(item.ToString(), sender.Font).Width))
                                   select width).Max();
 
                sender.DropDownWidth = largestItem > sender.Width ? largestItem : sender.Width;
            }
        }
    }
}

private void comboBoxTypes_DropDown(object sender, EventArgs e)
{
    comboBoxTypes.AutoSizeDropDownWidth();
}

newWidth = (int)((double)newWidth * 1.25);