Use of C # BackgroundWorker (background thread)

namespacebackgroundworkderpausesample{ Public Partial classMainform:form {BackgroundWorker worker=NULL;  PublicMainForm () {InitializeComponent (); Load+=NewEventHandler (Form1_Load); }        voidForm1_Load (Objectsender, EventArgs e) {Worker=NewBackgroundWorker (); Worker. Workerreportsprogress=true; Worker. Workersupportscancellation=true; Worker. DoWork+=NewDoworkeventhandler (worker_dowork); Worker. RunWorkerCompleted+=NewRunworkercompletedeventhandler (worker_runworkercompleted); Worker. ProgressChanged+=NewProgresschangedeventhandler (worker_progresschanged); }        voidWorker_progresschanged (Objectsender, ProgressChangedEventArgs e) {progressBar1.Value=E.progresspercentage; }        voidWorker_runworkercompleted (Objectsender, Runworkercompletedeventargs e) {            if(e.cancelled) MessageBox.Show ("the user canceled the Operation"); Else{MessageBox.Show ("The operation is completed normally"); }        }        voidWorker_dowork (Objectsender, DoWorkEventArgs e) {             for(inti =0; I < -; i++)            {                if(Worker. cancellationpending)//If the user requests a cancellation                {                     for(intK = i; K >=0; k--) {Thread.Sleep (Ten); Worker. ReportProgress (k);//simulate the effect of a rollback} e.cancel=true; return; } manualreset.waitone ();//if the ManualResetEvent is initialized to a terminating state (true), then the method will work until the reset signal is received.                Then, until the set signal is received, it continues to work. //vice versaThread.Sleep ( -); Worker. ReportProgress (i+1); }        }        Private voidBtstart_click (Objectsender, EventArgs e) {Worker.}        RunWorkerAsync (); }        Private voidBtcancel_click (Objectsender, EventArgs e) {Worker.}        CancelAsync (); }        PrivateManualResetEvent Manualreset =NewManualResetEvent (true); Private voidBtpause_click (Objectsender, EventArgs e) {            if(Btpause.text = ="Pause") {manualreset.reset ();//pauses the current thread's work, sends a signal to the WaitOne method, blocksBtpause.text ="continue to"; }            Else{manualreset.set ();//continue the work of a threadBtpause.text ="Pause"; }        }    }}

Use of C # BackgroundWorker (background thread)