Why is the variable counter 0 all the time?
<p>In the User Control code im doing in the top:</p>

<pre><code>int counter;
</code></pre>

<p>In constructor:</p>

<pre><code>counter = 0;
</code></pre>

<p>In the MouseDown event im doing:</p>

<pre><code>private void listBox1_MouseDown(object sender, MouseEventArgs e)
        {
            int index = listBox1.IndexFromPoint(e.X, e.Y);

            if (e.Button == System.Windows.Forms.MouseButtons.Right)
            {
                if (m_itemIndexes.Contains(index))
                    return;

                m_itemIndexes.Add(index);
                DrawItem(index);
                counter += 1;
            }
</code></pre>

<p>I used a breakpoint on the counter += 1; and saw that it's growing by one each time i click the right mouse button.</p>

<p>Then i add in the bottom a property for the counter:</p>

<pre><code>[Browsable(true)]
        public int RedCounts
        {
            get { return counter; }
            set
            {
                counter = value;
                Refresh();
            }
        }
</code></pre>

<p>Then in Form1 in the top i did:</p>

<pre><code>ListBoxControl lb1;
</code></pre>

<p>In constructor:</p>

<pre><code>lb1 = new ListBoxControl();
</code></pre>

<p>Then in the bottom of Form1 i added:</p>

<pre><code>private void deleteSelectedLightningsToolStripMenuItem_Click(object sender, EventArgs e)
            {
                if (MessageBox.Show("Are you Sure you want to delete " + lb1.RedCounts + " the selected files ? Click Yes to Confirm and No to continue", "WinForm", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.No)
                {

                }
                else
                {

                }
            }
</code></pre>

<p>But the result of RedCounts is all the time 0 i don't know why.</p>

<p>EDIT:</p>

<p>I found that if im doing instead of counter = 0; doing counter = 1; and instead of counter += 1; doing RedCounts += 1; Then using a breakpoint on the RedCounts i see that counter is growing by 1 starting from 1. 1,2,3,4....</p>

<p>The problem for some reason is in Form1 when i click the deleteSelectedLightningsToolStripMenuItem_Click using a breakpoint then lb1.RedCounts is 1 for some reason it's getting the value of 1 maybe from the property or from the line counter = 1; im not sure why. So if i set counter = 121; then lb1.RedCounts will show me 121. Strange.</p>

<p>This is the the full User Control with the counter and RedCounts:</p>

<pre><code>/*----------------------------------------------------------------
 * Module Name  : ListBoxControl
 * Description  : Change listBox items color
 * Author       : Danny
 * Date         : 30/12/2012
 * Revision     : 1.00
 * --------------------------------------------------------------*/

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;

/*
 *  Introduction :
 * 
 *  By default the color is red.
 *  Added a property to change the color.
 *  Right mouse click on item to change item color.
 *  Left mouse click on item to change the item color back.
 *  If the listBox is empty the control will be filled with 10 "Test" items.
 * */

namespace Lightnings_Extractor // to check how and change the namespace to listBoxControl
{
    public partial class ListBoxControl : UserControl
    {
        private Color m_MyListColor;
        private List&lt;int&gt; m_itemIndexes = new List&lt;int&gt;();
        private List&lt;int&gt; m_coloringItemIndexes = new List&lt;int&gt;();
        private int counter;
        public event EventHandler&lt;ItemEventArgs&gt; ItemRemoved;

        public List&lt;int&gt; Indices
        {
            get { return m_itemIndexes; }
        }

        public ListBoxControl()
        {
            InitializeComponent();

            counter = 1;
            if (listBox1.Items.Count == 0)
            {
                for (int i = 0; i &lt; 10; i++)
                {
                    listBox1.Items.Add("Test " + i);
                }
            }
        }

        private void listBox1_MouseDown(object sender, MouseEventArgs e)
        {
            int index = listBox1.IndexFromPoint(e.X, e.Y);

            if (e.Button == System.Windows.Forms.MouseButtons.Right)
            {
                if (m_itemIndexes.Contains(index))
                    return;

                m_itemIndexes.Add(index);
                DrawItem(index);
                RedCounts += 1;
            }
            else if (e.Button == MouseButtons.Left)
            {
                if (!m_itemIndexes.Contains(index))
                    return;

                m_itemIndexes.Remove(index);
                DrawItem(index);
                OnItemRemoved(index, listBox1.Items[index].ToString());
            }  
            listBox1.SelectedIndex = index;
        }

        protected virtual void OnItemRemoved(int indx, string name)
        {
            EventHandler&lt;ItemEventArgs&gt; handler = ItemRemoved;

            if(handler != null)
                ItemRemoved(this, new ItemEventArgs() {  Index = indx, Name = name});
        }

        private void listBox1_DrawItem(object sender, DrawItemEventArgs e)
        {
            m_MyListColor = MyListColor;
            if (m_MyListColor.IsEmpty == true)
            {
                m_MyListColor = Color.Red;
            }

            bool selected = (e.State &amp; DrawItemState.Selected) == DrawItemState.Selected;

            if (m_itemIndexes.Contains(e.Index))
            {
                using (var brush = new SolidBrush(m_MyListColor))
                {
                    e.Graphics.FillRectangle(brush, e.Bounds);
                }
            }
            else
            {
                e.DrawBackground();
            }

            string item = listBox1.Items[e.Index].ToString();
            e.Graphics.DrawString(item, e.Font, selected || m_itemIndexes.Contains(e.Index) ? Brushes.White : Brushes.Black, e.Bounds, StringFormat.GenericDefault);

            if (selected)
                e.DrawFocusRectangle();
        }

        private void DrawItem(int index)
        {
            Rectangle rectItem = listBox1.GetItemRectangle(index);
            listBox1.Invalidate(rectItem);
        }

        [Browsable(true)]
        public Color MyListColor
        {
            get { return m_MyListColor; }
            set
            {
                m_MyListColor = value;
                Refresh();
            }
        }

        [Browsable(true)]
        public ListBox MyListBox
        {
            get { return listBox1; }
            set
            {
                listBox1 = value;
                Refresh();
            }
        }

        [Browsable(true)]
        public int RedCounts
        {
            get { return counter; }
            set
            {
                counter = value;
                Refresh();
            }
        }

        private void ListBoxControl_Load(object sender, EventArgs e)
        {
            this.listBox1.SelectedIndex = 0;
        }
    }

    public class ItemEventArgs : EventArgs
    {
        public int Index { get; set; }
        public string Name { get; set; }
    }
}
</code></pre>
