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..”));
    }
});