android - onTouch() can't draw canvas -

ondraw(canvas canvas) works automatically. in view ontouch() method listens touching screen. need redraw rectangle when click on screen isn't drawing rectangle canvas.

public class viewer extends view implements ontouchlistener{      public viewer(context context) {         super(context);          .............         ..............         this.setontouchlistener(this);                   }      @override     public void ondraw(canvas canvas){           super .ondraw(canvas);         drawbackground(imgobj.bg01, canvas);         }      @override     public boolean ontouch(view v,motionevent event) {         // todo auto-generated method stub                canvas c = new canvas();         c.drawrect(.......);    //<------ it's work isn't redraw         return true;     } 

try this,

canvas mcanvas;  @override     public void ondraw(canvas canvas){            mcanvas = canvas;         drawbackground(imgobj.bg01, mcanvas);         super.ondraw(mcanvas);      }      @override     public boolean ontouch(view v,motionevent event) {         // todo auto-generated method stub                mcanvas.drawrect(.......);          invalidate();         return true;     }