从组合框删除所有项目后，C＃显示MessageBox

Question

I am trying to figure out, for an assignment, a way to display a message that basically says "combo box is empty" after I remove all items from a combo box in C#. The assignment is very simple. I write a windows form in C# that is populated with fifteen states in a ComboBox and when I select an item from that list it is removed. I have it working but once all the items are gone It just sits there and I have to manually exit. Can someone point me in the right direction to get this to work, I am thinking maybe if statement is in order? Here is my code so far...

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 Chapter_15_Ex._15._3
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            comboBox1.Items.Remove(comboBox1.SelectedItem);

        }


        private void btnExit_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}

Thank You

Answer 1

Check the number of items left, after you remove one. You can Count on the Items collection to see how many items are left in the ComboBox .

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    comboBox1.Items.Remove(comboBox1.SelectedItem);

    if (comboBox1.Items.Count == 0)
        MessageBox.Show("All Gone!");
}

Answer 2

        if (comboBox1.Items.Count == 0)
        {
            MessageBox.Show("Your combo is empty");
        }

Answer 3

You can check for the condition below

if (comboBox1.Items.Count == 0)
{
    MessageBox.Show("Empty");
}