sqliteopenhelper - Variable Passing in Android? -

i have variable currentdb in mainactivity.java. initiating variable different values depending upon user choosing different tabs. corresponding code :

@override public void tab_selector(view v) {     switch (v.getid()) {         case r.id.veg_tab:             setcontentview(r.layout.vegetable);             currentlistview = (listview) findviewbyid(r.id.veg_list);             currentdb = "veg";             break;         case r.id.meat_tab :             setcontentview(r.layout.meat_drawer);             currentlistview = (listview) findviewbyid(r.id.meat_list);             currentdb = "meat";             break;         default:             break;     }      currentlist = mydb.getallitems(currentdb);    // definition below, works perfect     itemadder2.updatedata(currentlist);     currentlistview.setadapter(itemadder2); } 

i have method in dbhelper.java ideally takes table name , item id input , deletes corresponding row specified table.

public integer deleteitem (string dbname, int id) {     sqlitedatabase db = this.getwritabledatabase();     return db.delete(dbname,             "id = ? ",             new string[] { integer.tostring(id) }); } 

this 1 more function obtain data table , works perfectly.

public arraylist<string> getallitems(string dbname) {     arraylist<string> array_list = new arraylist<string>();      //hp = new hashmap();     sqlitedatabase db = this.getreadabledatabase();     cursor res =  db.rawquery( "select * " + dbname, null );     res.movetofirst();      while(res.isafterlast() == false){         array_list.add(res.getstring(res.getcolumnindex(column_name)));         res.movetonext();     }     return array_list; } 

i have created customized listviewadapter in order display data stored in databases. have provided relevant buttons editing , deletion through onclick() functionality. now, problem identifying database refer inside listviewadapter. cannot pass currentdb information mainactivity.java listviewadapter.java. please help. in advance. code snippet listviewadapter.java follows :

public class listviewadapter extends baseadapter {  context mcontext; layoutinflater minflater; arraylist marray; dbhelper mydb; string dbname;  public listviewadapter(context context, layoutinflater inflater) {     mcontext = context;     minflater = inflater;     marray = new arraylist();     mydb = new dbhelper(mcontext);     dbname = "veg";    // didn't know do, tried initialize manually, din't work :( }  @override public int getcount() {     return marray.size(); }  @override public object getitem(int position) {     return marray.get(position); }  @override public long getitemid(int position) {     // particular data set uses string ids     // have put in method     return position; }  @override public view getview(final int position, view convertview, final viewgroup parent) {     viewholder holder;      // check if view exists     // if so, no need inflate , findviewbyid again!     if (convertview == null) {          // inflate custom row layout xml.         convertview = minflater.inflate(r.layout.list_item, null);          // create new "holder" subviews         holder = new viewholder();         holder.itemnameview = (textview) convertview.findviewbyid(r.id.item_name);         holder.itemexpiryview = (textview) convertview.findviewbyid(r.id.item_expiry);          // taking care of buttons         holder.editbutton = (button) convertview.findviewbyid(r.id.button_edit);         holder.deletebutton = (button) convertview.findviewbyid(r.id.button_delete);          // hang onto holder future recycling         convertview.settag(holder);     } else {          // skip expensive inflation/findviewbyid         // , holder made         holder = (viewholder) convertview.gettag();     }      // set listener on buttons     holder.editbutton.setonclicklistener(new view.onclicklistener() {          @override         public void onclick(view v) {             toast.maketext(mcontext, "edit button clicked", toast.length_short).show();         }     });      holder.deletebutton.setonclicklistener(new view.onclicklistener() {          @override         public void onclick(view v) {             deleteitem(position);            // potential problem here??             toast.maketext(mcontext, "item deleted", toast.length_short).show();         }     });      // more code after      // grab title , author json     string name = "";     string expiry = "7 days";      // write appropriate codes obtain values string variables above     name = (string) getitem(position);      // send these strings textviews display     holder.itemnameview.settext(name);     holder.itemexpiryview.settext(expiry);      return convertview; }  // used ever have // inflation , finding id once ever per view private static class viewholder {     public textview itemnameview;     public textview itemexpiryview;     public button editbutton;     public button deletebutton; }  public void updatedata(arraylist arraypassed) {     // update adapter's data set     marray = arraypassed;     notifydatasetchanged(); }  public void deleteitem(int pos){     marray.remove(pos);            // ideally, shouldn't there     mydb.deleteitem(dbname, pos);  // here need pass appropriate dbname     // marray = mydb.getallitems(); // ideally should there     notifydatasetchanged(); }  } 

please let me know if need extra. rephrase or topic, tag changes welcome. being noob, not capable how convey. appreciate help. :)

create public method in adapter set db name, eg : in listviewadapter class,

public void setdbname(string dbname){ this.dbname = dbname; } 

and on tab_selector(view v) method set db name adapter

eg :

@override public void tab_selector(view v) {     switch (v.getid()) {         case r.id.veg_tab:             setcontentview(r.layout.vegetable);             currentlistview = (listview) findviewbyid(r.id.veg_list);             currentdb = "veg";             break;         case r.id.meat_tab :             setcontentview(r.layout.meat_drawer);             currentlistview = (listview) findviewbyid(r.id.meat_list);             currentdb = "meat";             break;         default:             break;     }      currentlist = mydb.getallitems(currentdb);      itemadder2.updatedata(currentlist);     currentlistview.setadapter(itemadder2);     itemadder2.setdbname(currentdb ); }