android - dynamic add data to spinner but not update the data on the spinner -

 public class testaddspiner extends activity { private spinner m_mydynamicspinner; private edittext m_additemtext; private arrayadapter<charsequence> m_adapterforspinner; /** called when activity first created. */ @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.main);       m_mydynamicspinner = (spinner)findviewbyid(r.id.dynamicspinner);             m_additemtext = (edittext)findviewbyid(r.id.newspinneritemtext);     button addbutton = (button)findviewbyid(r.id.addbtn);     button clearbutton = (button)findviewbyid(r.id.clearbtn);       m_adapterforspinner = new arrayadapter(this, android.r.layout.simple_spinner_item);     m_adapterforspinner.setdropdownviewresource(android.r.layout.simple_spinner_dropdown_item);             m_mydynamicspinner.setadapter(m_adapterforspinner);     m_adapterforspinner.add("gr");               addbutton.setonclicklistener(new onclicklistener(){          @override         public void onclick(view v) {                            addnewspinneritem();         }                        });       clearbutton.setonclicklistener(new onclicklistener(){          @override         public void onclick(view v) {             clearspinneritems();         }                });   }  private void addnewspinneritem() {     charsequence textholder = "" + m_additemtext.gettext();     m_adapterforspinner.add(textholder);  }  private void clearspinneritems() {     m_adapterforspinner.clear();     m_adapterforspinner.add("dummy item"); }          } 

my spinner m_adapterforspinner update well,and if choice 1 m_adapterforspinner,it can show on spinner.i want add 1 data not show on m_adapterforspinner , show on spinner.

have tried select first item? spinner.setselection(0);?