How to quit an application programmatically through button click

use this it is work for me:

quitBtn.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View paramView) {

                moveTaskToBack(true); 
                MainActivity.this.finish();
            }
});

use this code...i hope this will help you..

  quitBtn.setOnClickListener(new View.OnClickListener() {         
        @Override
        public void onClick(View paramView) 
      {
            finish();          
            moveTaskToBack(true);
        }
    });