android - how to use arrayadapter.getview method -

here defined siteadapter , extends arrayadapter:

public class siteadapter extends arrayadapter<site> { private int resourceid; private list<site> sites = null; private context context; public siteadapter(context context, int resource, list<site> objects) {     super(context, resource, objects);     this.context = context;     this.resourceid = resource;     this.sites = objects; }  @override public site getitem(int position) {     return sites.get(position); }  @override public int getcount() {     return sites.size(); }  //get viewpage inflate site_layout.xml file @override public view getview(int position, view convertview, viewgroup parent) {     site site = getitem(position);     view view = convertview;     if (view == null) {         layoutinflater vi = (layoutinflater) context.getsystemservice(context.layout_inflater_service);         view = vi.inflate(resourceid, null);     }     //this place need whole widget in site_layout.xml file     imageview i1 = (imageview) view.findviewbyid(r.id.thumbnail);     textview address = (textview) view.findviewbyid(r.id.address);     textview t1 = (textview) view.findviewbyid(r.id.name);     textview t3 = (textview) view.findviewbyid(r.id.distance);     i1.setimageresource(site.getimageid());     address.settext(site.getaddress());     string name = site.getname();     string result = parse(name);     //set name of view     t1.settext(name);     t3.settext("<" + site.getdistance() + "m");      return view; } 

and in mainactivity, set listview using site adapter, , allocated r.drawable.blank value imageview , need change imageview, each row view through siteadapter getview method, view returned question why imageview inside such view can't replace new value(image), result turn out previous r.drawable.blank imageview:

here mainactivity snippet:

view view = siteadapter.getview(2, null, listview);         imageview image1 = ((imageview)view.findviewbyid(r.id.thumbnail));         image1.invalidate();         image1.setimageresource(r.drawable.amap_end);         siteadapter.notifydatasetchanged(); 

the point not have call getview() activity . called adapter .

now if want change imageview , should change sites list links adapter activity , call notifydatasetchanged() adapter .

activity :

 @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_home);          // setupviews         siteadapter adapter = new siteadapter(context,list<site> sites);         listview.setadapter(adapter);          // changing imageview         site site = sites.get(position);         site.setimage(r.drawable.*);          // updating site list new image         sites.set(position,site);          // refresh listview         adapter.notifydatasetchanged(); 

however , consider use recycleview instead of listview .