A problem with Android ListView

The function you need is simple, a list with a checkbox, and you need to know what the user has chosen for the project, as shown in the following figure:

Using Simpleadapter as the data adapter, rewrite the Simpleadapter.viewbinder method so that it is easier to use than the custom adapter, the code below

Datas definition is private list<map<string, object>> datas=null;

Where a self-referencing (my) binding to a checkbox is kept in the map

Private map<string, object> populatemap (String lblno,
map<string, object> ... maps) {
    
map< String, object> map = null;
if (Maps.length > 0) {
map = maps[0];
} else {
map = new hashmap<string, object> ();
}
    
Map.put ("Lblno", Lblno);
Map.put ("My", map);
Map.put ("Checked", true);
return map;
}

private void Bindadapter () {int[] to = new int[] {r.id.lblno,r.id.ckbit};
        String[] from = new string[] {"Lblno", "I"};
        adapter = new Simpleadapter (this, datas, R.layout.activity_post_list_item, from, to); ======= Add Delete event =======//View this column more highlights: Http://www.bianceng.cnhttp://www.bianceng.cn/OS/extra/SimpleAdapter.View
                        
            Binder Binder = new Simpleadapter.viewbinder () {private Boolean supressevent=false; @Override public boolean setviewvalue (view view, Object data, String Tex
                    
                Trepresentation) {Final Object d = data;
                     if (view instanceof CheckBox) {final map map= (map) D;
                     CheckBox ckb = (checkbox) view;
                     LOG.D ("T", "->map" +map);
                     Ckb.settag (map); Supressevent=tRue
                     There is a need to avoid triggering the Oncheckedchange event listening processing ckb.setchecked ((Boolean) map.get ("checked"));
                         
                     Supressevent=false; Ckb.setoncheckedchangelistener (New Oncheckedchangelistener () {@Overr
                        
                            IDE public void OnCheckedChanged (Compoundbutton buttonview, Boolean ischecked) {
                            LOG.D ("T", "Oncheckedchanged->map" +map + "ischecked:" +ischecked);
                            if (supressevent) return;
                            Map map= (map) Buttonview.gettag ();
                                
                                
                    
                                
                        Map.put ("Checked", ischecked);
                        
    
                    }
                    }); return true; Returning TRUE indicates that no parent class is required for default settings//reference HTTP://www.cnblogs.com/carmanloneliness/p/3500832.html//http://www.cnblogs.com/carmanloneliness/p/3500832
            . html} return false;
        }
        };
    
        Adapter.setviewbinder (binder);
    =======end======= Lv.setadapter (adapter); }

At the beginning, without a red comment, it is found that the Run-time program behavior is not always required.

It was later discovered that CKB triggers the Oncheckedchange handler when executing setchecked.

Simpleadapter is also a control reuse mechanism, which is when the list is dragged up and down, the controls that are dragged out of the screen are reused (binding the new data, the link in the reference code), due to the final implementation of the ckb.setchecked ((Boolean) Map.get ("checked")); Triggers the control's Oncheckedchange handler, which points to the data item that was previously bound, that is, the previous invocation of the Setviewvalue incoming data, which could result in an unexpected modification of a data in datas, resulting in uncertainty about the behavior of the program.

The solution is to execute ckb. When setchecked, the event handler excludes the drag list from generating messages based on this tag.