android - how save checkbox value with shared preferences? -
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- what nullpointerexception, , how fix it? 12 answers
hy everybody, don't know why code not save checkbox checked value; if check checkbox , after click on tab , comeback previous tab, checkbox not selected...i hope find error in code!
ide me: fatal exception: main java.lang.nullpointerexception @ line ".oncreateview(holder.chkbox.setchecked(true);"
why?
thanks in advance!
adapter class:
public abstract class planetadapter extends arrayadapter<planet> implements compoundbutton.oncheckedchangelistener { private list<planet> planetlist; private context context; arraylist<birra> objects; public planetadapter(list<planet> planetlist, context context) { super(context, r.layout.single_listview_item, planetlist); this.planetlist = planetlist; this.context = context; } public class planetholder { public textview planetname; public textview distview; public textview valuta; public checkbox chkbox; public edittext edit; public string quantità; } @override public view getview(int position, view convertview, viewgroup parent) { view row = convertview; planetholder holder = null; if (row == null) { layoutinflater inflater = ((activity) context).getlayoutinflater(); row = inflater.inflate(r.layout.single_listview_item, parent, false); holder = new planetholder(); holder.planetname = (textview) row.findviewbyid(r.id.name); holder.distview = (textview) row.findviewbyid(r.id.dist); holder.valuta = (textview) row.findviewbyid(r.id.valuta); holder.chkbox = (checkbox) row.findviewbyid(r.id.chk_box); holder.edit = (edittext) row.findviewbyid(r.id.edittext); holder.edit.setvisibility(view.gone); holder.edit.setenabled(false); row.settag(holder); } else { holder = (planetholder) row.gettag(); } final planet p = planetlist.get(position); final planetholder finalholder = holder; if(p.ischeckboxchecked ()) { finalholder.chkbox.setchecked(true); } /*sharedpreferences preferences = getcontext().getsharedpreferences("materialtabs", android.content.context.mode_private); boolean mcheckboxvalue = preferences .getboolean("checkbox_value", false); if (mcheckboxvalue) { holder.chkbox.setchecked(true); } else { holder.chkbox.setchecked(false); }*/ holder.chkbox.setonclicklistener(new view.onclicklistener() { @override public void onclick(view v) { if (finalholder.chkbox.ischecked()) { finalholder.edit.setvisibility(view.visible); finalholder.edit.setenabled(true); sharedpreferences preferences = getcontext().getsharedpreferences("materialtabs", android.content.context.mode_private); /* sharedpreferences.editor editor = preferences.edit(); editor.putboolean("showactivity", finalholder.chkbox.ischecked()); editor.commit();*/ // boolean value= true; sharedpreferences.editor meditor = preferences .edit(); meditor.putboolean("checkbox_value", finalholder.chkbox.ischecked()); meditor.commit(); finalholder.edit.addtextchangedlistener(new textwatcher() { @override public void beforetextchanged(charsequence s, int start, int count, int after) { } @override public void ontextchanged(charsequence s, int start, int before, int count) { } @override public void aftertextchanged(editable s) { p.setquantità(finalholder.edit.gettext().tostring().trim()); sharedpreferences preferences = getcontext().getsharedpreferences("project_name", android.content.context.mode_private); sharedpreferences.editor editor = preferences.edit(); editor.putstring("key", finalholder.edit.gettext().tostring().trim()); editor.commit(); } }); } else { finalholder.edit.setvisibility(view.gone); finalholder.edit.setenabled(false); finalholder.edit.settext(null); } } }); holder.planetname.settext(p.getname()); holder.distview.settext("" + p.getdistance()); holder.valuta.settext(""+p.getvaluta()); holder.chkbox.setchecked(p.isselected()); holder.chkbox.settag(p); holder.edit.setenabled(false); return row; } arraylist<planet> getbox() { arraylist<planet> box = new arraylist<planet>(); (planet p : planetlist) { if (p.selected) box.add(p); } return box; } } fragment:
public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) { // inflate layout fragment viewgroup rootview = (viewgroup) inflater.inflate(r.layout.fragment_list2, container, false); sharedpreferences preferences = getcontext().getsharedpreferences("materialtabs", android.content.context.mode_private); // preferences.getboolean("showactivity", false); //preferences.getstring("key", null); boolean mcheckboxvalue = preferences .getboolean("checkbox_value", false); if (mcheckboxvalue) { holder.chkbox.setchecked(true); } else { holder.chkbox.setchecked(false); } button mbutton = (button) rootview.findviewbyid(r.id.button); mbutton.setonclicklistener(new view.onclicklistener() { public void onclick(view v) { showresult(v); } }); //return inflater.inflate(r.layout.fragment_list2, container, false); return rootview; } planet:
class planet { string name; int distance; string quantità; string valuta; boolean selected = false; boolean mcheckboxstate; public planet(string name, int distance, string valuta) { super(); this.name = name; this.distance = distance; this.valuta = valuta; } public string getname() { return name; } public void setname(string name) { this.name = name; } public int getdistance() { return distance; } public void setdistance(int distance) { this.distance = distance; } public boolean isselected() { return selected; } public void setselected(boolean selected) { this.selected = selected; } public string getquantità() { return quantità; } public void setquantità(string quantità) { this.quantità = quantità; } public string getvaluta() { return valuta; } public void setvaluta(string valuta) { this.valuta = valuta; } public boolean ischeckboxchecked () { return mcheckboxstate; } private void setcheckboxcheck(boolean state){ mcheckboxstate = state; } }
the fragment views refreshed each time better option instead of storing in preferences make use of item (object) used create value ex in adapter carry out operation final planet p = planetlist.get(position);
final planetholder finalholder = holder; //set check box if checked if(p.ischeckboxchecked) { finalholder.chkbox.setchecked(true); } holder.chkbox.setonclicklistener(new view.onclicklistener() { @override public void onclick(view v) { if (finalholder.chkbox.ischecked()) { finalholder.edit.setvisibility(view.visible); finalholder.edit.setenabled(true); sharedpreferences preferences = getcontext().getsharedpreferences("materialtabs", android.content.context.mode_private); /* sharedpreferences.editor editor = preferences.edit(); editor.putboolean("showactivity", finalholder.chkbox.ischecked()); editor.commit();*/ // boolean value= true; sharedpreferences.editor meditor = preferences .edit(); meditor.putboolean("checkbox_value", finalholder.chkbox.ischecked()); meditor.commit(); finalholder.edit.addtextchangedlistener(new textwatcher() { @override public void beforetextchanged(charsequence s, int start, int count, int after) { } @override public void ontextchanged(charsequence s, int start, int before, int count) { } @override public void aftertextchanged(editable s) { //set item been checked p.setcheckboxcheck(true); } }); } else { finalholder.edit.setvisibility(view.gone); finalholder.edit.setenabled(false); finalholder.edit.settext(null); } } });
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