Csharp/C Sharp/Thread/Thread and GUI

Demonstrates hiding a form and then doing background processing in a second thread

/*
C# Programming Tips & Techniques
by Charles Wright, Kris Jamsa
Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/
// HideForm.cs -- Demonstrates hiding a form and then doing background
//                processing in a second thread.
//
//                Compile this program with the following command line:
//                    C:>csc HideForm.cs
using System;
using System.Windows.Forms;
using System.Threading;
namespace HideForm
{
    public class HideForm : System.Windows.Forms.Form
    {
        private System.Windows.Forms.Button button1;
        public HideForm()
        {
            Text = "A Simple Form";
            button1 = new Button ();
            SuspendLayout();
            button1.Text = "Cancel";
            button1.Name = "button1";
            button1.Size = new System.Drawing.Size (72, 30);
            button1.Location = new System.Drawing.Point ((ClientRectangle.Width - button1.Size.Width) / 2, ClientRectangle.Height - 35);
            Controls.AddRange(new System.Windows.Forms.Control[] {this.button1});
            button1.Click += new System.EventHandler(OnClickButton1);
            this.Closed += new System.EventHandler(OnClickButton1);
            ResumeLayout (false);
            this.Visible = false;
        }
        [STAThread]
        static void Main() 
        {
            HideForm form = new HideForm();
            Thread delay = new Thread (new ThreadStart(form.DelayVisible));
            delay.Start ();
            Application.Run();
        }
        public void DelayVisible ()
        {
            while (true)
            {
                Thread.Sleep (2500);
                DialogResult result = MessageBox.Show ("Display Form?", "Display", MessageBoxButtons.YesNoCancel);
                switch (result)
                {
                    case DialogResult.Yes:
                        this.ShowDialog();
                        return;
                    case DialogResult.No:
                        continue;
                    case DialogResult.Cancel:
                        Application.Exit ();
                        break;
                }
                return;
            }
        }
        private void OnClickButton1(object sender, System.EventArgs e)
        {
            Application.Exit ();
        }
    }
}

Thread and GUI

/*
Professional Windows GUI Programming Using C#
by Jay Glynn, Csaba Torok, Richard Conway, Wahid Choudhury, 
   Zach Greenvoss, Shripad Kulkarni, Neil Whitlow
Publisher: Peer Information
ISBN: 1861007663
*/
using System;
using System.Drawing;
using System.Collections;
using System.ruponentModel;
using System.Windows.Forms;
using System.Data;
using System.Threading;
namespace Wrox.WindowsGUIProgramming.Chapter9
{
    /// <summary>
    /// Summary description for Form1.
    /// </summary>
    /// 
    struct _threadstart
    {
        public ThreadStart threadstart;
        public DateTime dt;
    }
    public class frmWasteTime : System.Windows.Forms.Form
    {
        private System.Windows.Forms.Button butWasteTime;
        private System.Windows.Forms.TextBox textBox1;
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ruponentModel.Container components = null;
        private System.Windows.Forms.ListBox lbThreads;
        private System.Windows.Forms.TextBox txtNoOfThreads;
        private System.Windows.Forms.Button btThreadStart;
        private System.IAsyncResult m_EndInvoke = null;
        public frmWasteTime()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();
            //
            // TODO: Add any constructor code after InitializeComponent call
            //
            this.Show();
            //TakeTime();
        }
        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if (components != null) 
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }
        #region Windows Form Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.butWasteTime = new System.Windows.Forms.Button();
            this.textBox1 = new System.Windows.Forms.TextBox();
            this.lbThreads = new System.Windows.Forms.ListBox();
            this.txtNoOfThreads = new System.Windows.Forms.TextBox();
            this.btThreadStart = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // butWasteTime
            // 
            this.butWasteTime.Location = new System.Drawing.Point(88, 32);
            this.butWasteTime.Name = "butWasteTime";
            this.butWasteTime.TabIndex = 0;
            this.butWasteTime.Text = "Waste Time";
            this.butWasteTime.Click += new System.EventHandler(this.butWasteTime_Click);
            // 
            // textBox1
            // 
            this.textBox1.Location = new System.Drawing.Point(184, 24);
            this.textBox1.Name = "textBox1";
            this.textBox1.TabIndex = 1;
            this.textBox1.Text = "";
            // 
            // lbThreads
            // 
            this.lbThreads.Location = new System.Drawing.Point(8, 64);
            this.lbThreads.Name = "lbThreads";
            this.lbThreads.Size = new System.Drawing.Size(280, 277);
            this.lbThreads.TabIndex = 2;
            // 
            // txtNoOfThreads
            // 
            this.txtNoOfThreads.Location = new System.Drawing.Point(8, 352);
            this.txtNoOfThreads.Name = "txtNoOfThreads";
            this.txtNoOfThreads.TabIndex = 3;
            this.txtNoOfThreads.Text = "";
            // 
            // btThreadStart
            // 
            this.btThreadStart.Location = new System.Drawing.Point(128, 352);
            this.btThreadStart.Name = "btThreadStart";
            this.btThreadStart.Size = new System.Drawing.Size(160, 23);
            this.btThreadStart.TabIndex = 4;
            this.btThreadStart.Text = "Start";
            this.btThreadStart.Click += new System.EventHandler(this.btThreadStart_Click);
            // 
            // frmWasteTime
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(296, 390);
            this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                          this.btThreadStart,
                                                                          this.txtNoOfThreads,
                                                                          this.lbThreads,
                                                                          this.textBox1,
                                                                          this.butWasteTime});
            this.Name = "frmWasteTime";
            this.Text = "Lock Form";
            this.Paint += new System.Windows.Forms.PaintEventHandler(this.painting);
            this.ResumeLayout(false);
        }
        #endregion
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main() 
        {
            Application.Run(new frmWasteTime());
        }
        private void TakeTime()
        {
            int j = 0;
            for(int i=0;i<320-j;i++)
            {
                System.Diagnostics.Debug.Write(i);
            }
            j++;
        }
        private void butWasteTime_Click(object sender, System.EventArgs e)
        {
            IAsyncResult m_EndInvoke2 = null;
            ThreadStart threadstart = new ThreadStart(TakeTime);
            m_EndInvoke = threadstart.BeginInvoke(new AsyncCallback(MethodBeginInvoke), String.Copy("test"));
            ThreadStart threadstart2 = new ThreadStart(TakeTime);
            m_EndInvoke2 = threadstart.BeginInvoke(new AsyncCallback(MethodBeginInvoke), null);
            //m_EndInvoke.AsyncWaitHandle.WaitOne();
            threadstart.EndInvoke(m_EndInvoke);
            threadstart.EndInvoke(m_EndInvoke2);
            /*while(true)
            {
                if(m_EndInvoke.IsCompleted)
                    MessageBox.Show("finally!!!");
                    break;
            }*/
        }
        private void MethodBeginInvoke(System.IAsyncResult ar)
        {
            if(ar.rupletedSynchronously)
              MessageBox.Show("TakeTime() called synchronously");   
            else
              MessageBox.Show("TakeTime() called asynchronously");  
        }
        protected override void OnPaint(PaintEventArgs pe)
        {
            System.Diagnostics.Debug.Write("Paint event called");
            
        }
        private void painting(object sender, System.Windows.Forms.PaintEventArgs e)
        {
            System.Diagnostics.Debug.Write("Paint event called");
        }
        //System.Threading.ThreadStart[] threads;
        //DateTime[] dateTimeThread;
        _threadstart[] th;
        DateTime dtStart;
        DateTime dtEnd;
        private void btThreadStart_Click(object sender, System.EventArgs e)
        {
            
            th = new _threadstart[Convert.ToInt32(txtNoOfThreads.Text)];
            //threads = (ThreadStart[])Array.CreateInstance(typeof(ThreadStart), Convert.ToInt16(txtNoOfThreads.Text));
            //dateTimeThread = (DateTime[])Array.CreateInstance(typeof(DateTime), threads.Length);
            dtStart = DateTime.Now;
            for(int i = 0; i < th.Length; i++)
            {
                th[i].threadstart = new ThreadStart(TakeTime);
                th[i].threadstart.BeginInvoke(new AsyncCallback(ThreadFinished), i);
                th[i].dt = DateTime.Now;
            }
            /*while(true)
            {
                for(int i = 0; i < threads.Length; i++)
                {
                    if((threads[i].ThreadState == System.Threading.ThreadState.Suspended) && finished[i].Equals(false))
                    {
                        //put something into the listbox
                        lbThreads.Items.Insert(i, "Thread "+i+" finished - "+(DateTime.Now.Subtract(dateTimeThread[i])));
                        finished[i] = true;
                    }
                    Refresh();
                }
            }*/
        }
        void FinalCallback(string blank)
        {
            dtEnd = DateTime.Now.Subtract(new TimeSpan(dtStart.Ticks));
            lbThreads.Items.Add("Total Thread Time: "+((dtEnd.Minute*60)+dtEnd.Second).ToString()+" seconds");
            lbThreads.Items.Add("Average Thread Time: "+(((dtEnd.Minute*60)+dtEnd.Second)/th.Length)+" seconds");
        }
        void UpdateListbox(string listboxText)
        {
             lbThreads.Items.Add(listboxText);
        }
        delegate void ItemAdd(string item);
        private void ThreadFinished(IAsyncResult ar)
        {
            ItemAdd ia = new ItemAdd(UpdateListbox);
            ItemAdd ib = new ItemAdd(FinalCallback);
            int i = (int)ar.AsyncState;
            string state = "Thread "+(i+1)+" finished - "+(DateTime.Now.Subtract(th[i].dt)).ToString();
            //put something into the listbox
            if(lbThreads.InvokeRequired)
            {
                lbThreads.Invoke(ia, new Object[] {state});
            }
            else
            {
                lbThreads.Items.Add(state);
            }
            if(i==(th.Length-1)) lbThreads.Invoke(ib, new Object[]{""});
        }
    }
}