android - UIThread is causing problems when I want to open a new Activity -

i have surfaceview in activity, , want open new activity when occurs in surfaceview(when run out of lives - lives == 0). i've tried different things, keep having problems it. if stop uithread first, of course won't keep running , won't able execute startactivity statement. if start activity, freezes on me , force closes - having uithread believe. has run problem before - , if so, have idea how might go achieving this. @ least, if can't open new activity, how close current activity (from inside surfaceview).

public class boardview extends surfaceview implements surfaceholder.callback{ context mcontext;  // thread initialization private boardthread thread; thread timer; thread timer2;  // box variables bitmap box =      (bitmapfactory.decoderesource             (getresources(), r.drawable.box)); private int box_x = 140; private int box_y = 378; private int boxwidth = box.getwidth(); private int boxheight = box.getheight();  // storage private vector<blossom> blossomvector = new vector<blossom>(); iterator<blossom> dataiterator = blossomvector.iterator();  // counters private int blossomnum = 0; private string score; private int currentscore = 0; private int lives = 3;  boolean mode = false; boolean game = false;  outputstreamwriter out = null; fileoutputstream fout = null;  private static final string tag = "debug"; final paint scorepaint = new paint();  public boardview(context context){     super(context);      scorepaint.setcolor(color.black);     scorepaint.settextsize(12);     scorepaint.settypeface(typeface.monospace);       //surfaceholder provides canvas draw on     getholder().addcallback(this);      //set read/write data     file root = environment.getexternalstoragedirectory();     file highscoresfile = new file(root, "highscores.txt");       // controls drawings     thread = new boardthread(getholder(),this, blossomvector, dataiterator, box_x, box_y,              boxwidth, boxheight);      timer2 = new thread(){         public void run(){             while(game == false){                 uicallback.sendemptymessage(0);                 try{                     thread.sleep(5000); // change random                 }                 catch (interruptedexception e){                     e.printstacktrace();                 }             }         }     };      timer = new thread(){         public void run(){             //makes sure player still has 3 lives left             while(game == false){                 uicallback.sendemptymessage(0);                 try {                     thread.sleep(2000); // wait 2 seconds before drawing next flower                 } catch (interruptedexception e) {                     // todo auto-generated catch block                     e.printstacktrace();                 } //sleep 2 seconds             }         }     };     timer.start();     timer2.start();       //intercepts touch events     setfocusable(true);  }   @override  public void ondraw(canvas canvas){     canvas.drawcolor(color.white);     score = "score: " + currentscore;      //note: pay attention order draw things     //don't change order or else blossoms fall     //on top of box, not "into" it.      //display scoreboard     canvas.drawtext(score,240,420,scorepaint);     // uses synchronized method prevent concurrent modification     drawblossoms(canvas);     canvas.drawbitmap(box, box_x, box_y, null);  }  @override public boolean ontouchevent(motionevent event){     //handles movement of box     if(event.getaction() == motionevent.action_down){         if(event.getx() > box_x & event.gety() > box_y &                  event.getx() < box_x + boxwidth & event.gety() < box_y + boxheight)         {             mode = true;         }     }      if(event.getaction() == motionevent.action_move) {         if(event.getx() > box_x & event.gety() > box_y &                  event.getx() < box_x + boxwidth & event.gety() < box_y + boxheight)         {             mode = true;         }         if(mode == true){             box_x = (int)event.getx();         }         }      if(event.getaction() == motionevent.action_up){         mode = false;     }      invalidate();     return true; }  @override public void surfacechanged(surfaceholder holder,          int format, int width, int height ){     log.v(tag, "surface changed");     //somehow these don't seem working }  @override public void surfacecreated(surfaceholder holder){     thread.startrunning(true);     thread.start(); }  @override public void surfacedestroyed(surfaceholder holder){     log.v(tag, "surface destroyed");     try {     thread.join(); } catch (interruptedexception e) {     // todo auto-generated catch block     e.printstacktrace(); }  }  private handler uicallback = new handler(){     public synchronized void handlemessage(message msg){         //add new blossom blossom vector!!         blossomvector.add(new blossom(              (bitmapfactory.decoderesource                     (getresources(), r.drawable.blossom))));         dataiterator = blossomvector.iterator();         blossomnum++;         log.v(tag, "number of blossoms =" + blossomnum);     } };   private synchronized void drawblossoms(canvas c) // method draw flowers on screen , test collision {     canvas canvas = c;     dataiterator = blossomvector.iterator();     while (dataiterator.hasnext())     {         blossom tempblossom = dataiterator.next();         tempblossom.draw(canvas);         if (tempblossom.hit(box_x,box_y, box_x + boxwidth, box_y + boxheight, blossomvector) == true)         {             log.v(tag, "iterator works!");             dataiterator.remove();             currentscore += 100;         }          if (tempblossom.dropped() == true)         {             dataiterator.remove();             log.v(tag, "blossom dropped");             lives--;         }         if (lives == 0)         {             // stop thread makes blossoms             game = true;             //save highscore             try {                 file root = environment.getexternalstoragedirectory();                 if(root.canwrite()){                 file highscoresfile = new file(root, "highscores.txt");                 filewriter writer = new filewriter(highscoresfile);                 bufferedwriter out = new bufferedwriter(writer);                 //out.newline();                 out.write(score);                 out.close();                 }             } catch (filenotfoundexception e1) {                 // todo auto-generated catch block                 e1.printstacktrace();             } catch (ioexception e) {                 // todo auto-generated catch block                 e.printstacktrace();             }              try {                 file root = environment.getexternalstoragedirectory();                 file highscoresfile = new file(root, "highscores.txt");                 filereader reader = new filereader(highscoresfile);                 bufferedreader in = new bufferedreader(reader);                 try {                     string scoretest = in.readline();                     log.v(tag, "score: " + scoretest);                     reader.close();                  } catch (ioexception e) {                     // todo auto-generated catch block                     e.printstacktrace();                 }             } catch (filenotfoundexception e1) {                 // todo auto-generated catch block                 e1.printstacktrace();             }          try {             thread.join();         } catch (interruptedexception e) {             // todo auto-generated catch block             e.printstacktrace();         }           }      } } 

}

board thread`public class boardthread extends thread {

private surfaceholder surfaceholder; private boardview boardview;  private vector<blossom> blossomvector; private int boxx; private int boxy; private int boxwidth; private int boxheight; private boolean mrun =false; private iterator<blossom> iterator;  private static final string tag = "debug";  public boardthread(surfaceholder holder, boardview boardview2,          vector<blossom> blossomvector1, iterator<blossom> dataiterator,         int box_x, int box_y, int boxw, int boxh) {      surfaceholder = holder;     boardview=boardview2;      blossomvector = blossomvector1;     iterator = dataiterator;     boxx = box_x;     boxy = box_y;     boxw = boxwidth;     boxh = boxheight; }  public void startrunning(boolean run) {      mrun=run; }  @override public void run() {      super.run();      canvas canvas;      while (mrun) {         canvas=null;          try {              canvas = surfaceholder.lockcanvas(null);               synchronized (surfaceholder) {                  //update position                  //position(blossomvector, boxx, boxy, boxwidth, boxheight);                  // draw flowers                  boardview.ondraw(canvas);              }          } {                  if (canvas != null) {                  surfaceholder.unlockcanvasandpost(canvas);              }          }      }   }  private synchronized void position(vector<blossom> blossomvector,int box_x, int box_y,          int boxwidth, int boxheight) {     //for(blossom blossom: blossomvector)     iterator = blossomvector.iterator();     while (iterator.hasnext())     {         blossom tempblossom = iterator.next();         tempblossom.updateposition();      } }  } 

`

sounds surfaceview running in different thread main ui thread , can't modify view objects. you'll want create handler in activity , make accessible surfaceview. can send message handler , can update ui (or launch new activity) in main ui thread.