You can perform your action on button click-

      btn.setOnClickListener(new View.OnClickListener() {

    public void onClick(View v) {

            Intent send = new Intent(Intent.ACTION_SEND);

            send.setType("text/plain");

            send.putExtra(Intent.EXTRA_TEXT, “This is demo message  ");

            startActivity(Intent.createChooser(send, "Send via..”));

    }

});