multithreading - C# Execute method after background thread finished -

i'm using thread run calculation in background of program. start thread @ start of program. if press button before thread finished open statusbar , "openedstatus" set true.

this show threads current progress , after thread has finished execute last part of code:

if (openedstatus) {     sb.close();     validatebeforesave(); } 

this part of code throw exception though because can't close statusbar cross-thread.

now question is: how can execute last part of code after thread finished?

private statusbar sb = new statusbar(); private void startvoorraadcalculationthread() {     sb.setmaxprogress(data.getproducten().getproductencopy().count);     thread thread = new thread(new threadstart(this.run));     thread.start();     while (!thread.isalive) ; }  private void run() {     (int = 0; < data.getproducten().getproductencopy().count; i++ )     {         sb.setprogress(i);         sb.setstatus("calculating voorraad: " + (i+1) + "/" + data.getproducten().getproductencopy().count);         data.getproducten().getproductencopy()[i].gettotaalvoorraad(data.getmaten());     }     if (openedstatus)     {         sb.close();         validatebeforesave();     }     calculationfinished = true; } 

using backgroundworker fixed problem:

private void startvoorraadcalculationthread() {     sb.setmaxprogress(data.getproducten().getproductencopy().count);      backgroundworker bw = new backgroundworker();     bw.dowork += new doworkeventhandler(bw_dowork);     bw.runworkercompleted += new runworkercompletedeventhandler(bw_runworkercompleted);      bw.runworkerasync(); }  private void bw_dowork(object sender, doworkeventargs e) {     (int = 0; < data.getproducten().getproductencopy().count; i++)     {         sb.setprogress(i);         sb.setstatus("calculating voorraad: " + (i + 1) + "/" + data.getproducten().getproductencopy().count);         data.getproducten().getproductencopy()[i].gettotaalvoorraad(data.getmaten());     } }  private void bw_runworkercompleted(object sender, runworkercompletedeventargs e) {     if (openedstatus)     {         sb.close();         validatebeforesave();     }     calculationfinished = true; }