c# - Multi thread is created when called inside a delegate? -

i have created file upload windows application in c#. have problem, using delegate function starting new thread file upload. it's works fine, happens instead of creating single thread, created 2 thread 1 after another. call delegate function , inside function starting new thread. when debugging found out delegate function called once, thread.start calling multiple times. please find code flow

public delegate void calltransactionstartdelegate(int transid); private wts_manager privateui = new wts_manager();  function starttrans() {     calltransactionstartdelegate dlgstartmanualtrans = new calltransactionstartdelegate  (privateui.startmanualtransaction);      loginfo.writelogsinformation("before calling startmanualtransaction method");     privateui.invoke(dlgstartmanualtrans,new object[]{txid}); }  wts_manager form class code ----------------------  public void startmanualtransaction(int transid) {     loginfo.writelogsinformation("inside startmanualtransaction method");     new fileupload(transid,this).start(); }  fileupload class file ----------------------  public fileupload(int transid, wts_manager parentui) { // initialised code here.. } public void start() {     loginfo.writelogsinformation("inside fileupload start method");     thread th = new thread(new threadstart(startupload));     th.start(); }  public void startupload() {     loginfo.writelogsinformation("inside startupload method");     // have written code file upload.. } 

here written in log file

11/10/2016 6:21:55 pm threadid :- 7  processid :- 380 before calling startmanualtransaction method 11/10/2016 6:21:55 pm threadid :- 1  processid :- 380 inside startmanualtransaction method 11/10/2016 6:21:55 pm threadid :- 1  processid :- 380 inside fileupload start method 11/10/2016 6:21:55 pm threadid :- 8  processid :- 380 inside startupload method 11/10/2016 6:21:57 pm threadid :- 11  processid :- 380 inside startupload method 

i not able understand why 2 threads created?

rajagopalan