C # Multithreading concurrency

PublicPartialClassMultithread:Form {Publicint threadh;Thread CodePublicString strURL;The URL of the receiving filePublicFileStream FS;PublicHttpWebRequest request;PublicByte[] nbytes;Receive buffersPublicint nreadsize;Number of bytes Receivedint conts;int conted;Public multithread () {The error thread is not called System.Windows.Forms.Control.checkforillegalcrossthreadcalls =False        InitializeComponent (); }ThreadStart startPrivatevoid Butquantity_click (Object sender,EventArgs e) {if (txtquantity. Text! ="") {conts =Convert.ToInt32 (txtquantity. Text);thread[] Threads =NewThread[conts];for (int i = 0; i < conts; i++) {Threads[i] =NewThread (NewThreadStart (readhttp)); Threads[i]. Name = i.tostring () +"Thread number"; }foreach (Thread TIn threads) {T.start ();TextBox2.Text = Thread.CurrentThread.Name;            } initializetimer (); }else {MessageBox.Show ("The number of requests cannot be empty!" ","ERROR"); }        }Privatevoid Timerclock_elapsed (Object Source,Elapsedeventargs e) {if (txtquantity. Text! ="") {conts =Convert.ToInt32 (txtquantity. Text);thread[] Threads =NewThread[conts];for (int i = 0; i < conts; i++) {Threads[i] =NewThread (NewThreadStart (readhttp)); Threads[i]. Name = i.tostring () +"Thread number"; }foreach (Thread TIn threads) {T.start (); }            }else {MessageBox.Show ("The number of requests cannot be empty!" ","ERROR"); }        }Send RequestPrivatevoid Readhttp () {try {conted =Convert.ToInt32 (txtquantity.                Text); System.Net.WebClient client =New System.Net.WebClient (); strURL = Txtaddress.text;This.textBox2.Text = "Requesting" + strURL;Stream st = client. OpenRead (strURL);StreamReader sr =NewStreamReader (ST);string res = Sr. ReadToEnd ();if (res! =NULL) {LISTBOX1.ITEMS.ADD ("-" +Thread.CurrentThread.Name +"Success"); }else {LISTBOX1.ITEMS.ADD ("-" +Thread.CurrentThread.Name +"Failure"); } Sr.                Close (); St. Close ();Thread.Sleep (2000); }catch (Exception e) {MessageBox.Show (E.message,"Hint:");Throw }        }Publicvoid Initializetimer () {system.timers.Timer timerclock = new system.timers.             Timer ();            timerclock.elapsed + = new elapsedeventhandler (timerclock_elapsed);            //timerclock.interval = 1000 * 60 * 3;            Timerclock.interval = 3000;         timerclock.enabled = true; }     }}

C # Multithreading concurrency