Say we have a Form F, containing a UserControl Uc, which does some
action on a WindowsTimer callback. If F also contains a timer and this
timer has an interval shorter than its callback latency, then
Uc.Dispose() will cause an infinite loop.

The attached sample ilustrates the problem. Pressing a button
toggles between creating/destroying a UserControl. This works fine as
long as the form's timer callback is kept under <100 ms (the form's
timer interval). The attached sample uses 200ms and locks up after
pressing the create/destroy button a couple of times.

Any suggestions for workarounds? TIA.

-------------------------------------------------------

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;

namespace WindowsApplication4
{
  public class UserControl1 : System.Windows.Forms.UserControl
  {
     private System.Windows.Forms.Timer timer1;
     private System.ComponentModel.IContainer components;
     
     public UserControl1()
     {
        this.components = new System.ComponentModel.Container();
        this.timer1 = new System.Windows.Forms.Timer(this.components);

        this.timer1.Enabled = true;
        this.timer1.Tick += new System.EventHandler(this.timer1_Tick);

        this.BackColor = System.Drawing.Color.RosyBrown;
        this.Name = "UserControl1";
        this.Size = new System.Drawing.Size(104, 24);
     }

     protected override void Dispose( bool disposing )
     {
        if( disposing )
        {
           if(components != null)
           {
              components.Dispose();
           }
        }
        base.Dispose( disposing );
     }

     private void timer1_Tick(object sender, System.EventArgs e)
     {}
  }

  public class Form2 : System.Windows.Forms.Form
  {
     private System.Windows.Forms.Timer timer1;
     private System.Windows.Forms.Button button1;
     private System.ComponentModel.IContainer components;

     [STAThread]
     public static void Main()
     {
        Application.Run(new Form2());
     }

     public Form2()
     {
        InitializeComponent();
     }

     private void InitializeComponent()
     {
        this.components = new System.ComponentModel.Container();
        this.timer1 = new System.Windows.Forms.Timer(this.components);
        this.button1 = new System.Windows.Forms.Button();
        this.SuspendLayout();

        this.timer1.Enabled = true;
        this.timer1.Tick += new System.EventHandler(this.timer1_Tick);

        this.button1.Location = new System.Drawing.Point(112, 192);
        this.button1.Text = "Ok";
        this.button1.Click += new System.EventHandler(this.button1_Click);

        this.Controls.Add(this.button1);
        this.ResumeLayout(false);

     }

     UserControl1 myUserControl;
   
     private void button1_Click(object sender, System.EventArgs e)
     {
        if (myUserControl == null)
        {
           myUserControl = new UserControl1();
           myUserControl.Parent = this;
        }
        else
        {
           myUserControl.Dispose();
           myUserControl = null;
        }
     }

     private void timer1_Tick(object sender, System.EventArgs e)
     {
        System.Threading.Thread.Sleep(200);
     }
  }
}