问题
In my android application, I am trying to show contextual action bar (CAB) in listview for item delete. The problem is that whenever an item is pressed for long, the item gets selected, but CAB doesn't appear. I have verified with so many tutorials, can't figure out what am I missing. Any help would be appreciated.
Adapter Class
public class DuasListAdapter extends ArrayAdapter<String>{
// class variables
private final Context context;// to save context
private final List<String> duas;// to save list of stores
LayoutInflater inflater;//
private SparseBooleanArray selectedItemsIds;
public DuasListAdapter(Context ctx,int resourceId, List<String> duasList) {
super(ctx, resourceId, duasList);
selectedItemsIds = new SparseBooleanArray();
context = ctx;// save context
duas = duasList;// save list of stores
inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);// save inflater layout
}
*/
@Override
public View getView(int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
if(convertView==null){
holder = new ViewHolder();
convertView = inflater.inflate(R.layout.adapter_list_duas, null);
convertView.setTag(holder);
holder.duaIndex = position;
holder.background = (LinearLayout) convertView.findViewById(R.id.ll_duas_list);
holder.iv_duatype = (ImageView) convertView.findViewById(R.id.iv_duatype);
holder.tv_dua_arabic = (TextView) convertView.findViewById(R.id.tv_dua_arabic);
holder.tv_dua_no = (TextView) convertView.findViewById(R.id.dua_no);
}
else {
holder = (ViewHolder) convertView.getTag();
}
return convertView;
}
static class ViewHolder {
int duaIndex;
LinearLayout background;// background to display color for read and unread messages
ImageView iv_duatype;
TextView tv_dua_arabic;// title of message
TextView tv_dua_ref;// message by and message created on
TextView tv_dua_no;
/**
* @description constructor to save context and list of stores views
* @param v to refer the view
* @return
*/
}
public void remove(List<String> object){
duas.remove(object);
notifyDataSetChanged();
}
public List<String> getDuas(){
return duas;
}
public void toggleSelection(int position) {
selectView(position, !selectedItemsIds.get(position));
}
public void removeSelection() {
selectedItemsIds = new SparseBooleanArray();
notifyDataSetChanged();
}
public void selectView(int position, boolean value) {
if (value)
selectedItemsIds.put(position, value);
else
selectedItemsIds.delete(position);
notifyDataSetChanged();
}
public int getSelectedCount() {
return selectedItemsIds.size();
}
public SparseBooleanArray getSelectedIds() {
return selectedItemsIds;
}
}
Fragment Class
Context context;
LinearLayout ll_back_duas_list_header;
TextView ll_back_duas_list_header_title;
ListView lvDuaas;
public static DuasListAdapter duasAdapter;
ActionMode mAction;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
context = inflater.getContext();
View view = inflater.inflate(R.layout.fragment_list_duas, container, false);
ll_back_duas_list_header = (LinearLayout) view.findViewById(R.id.ll_back_duas_list_header);
ll_back_duas_list_header_title = (TextView) view.findViewById(R.id.ll_back_duas_list_header_title);
lvDuaas = (ListView) view.findViewById(R.id.lv_duas);
setHasOptionsMenu(true);
return view;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
String verses = new SharedPreferencesSupplication().read(SingletonClass.keyListOfVerses, "a1");
String[] versesList = verses.split(",");
final ArrayList<String> duas = new ArrayList<String>();
for (int i = 0; i < versesList.length; i++) {
if (versesList[i].length() > 0)
duas.add(versesList[i]);
}
duasAdapter = new DuasListAdapter(context,R.layout.adapter_list_duas,duas);
lvDuaas.setAdapter(duasAdapter);
lvDuaas.setOnItemLongClickListener(new OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent,
View view, int position, long id) {
// TODO Auto-generated method stub
lvDuaas.setChoiceMode(lvDuaas.CHOICE_MODE_MULTIPLE);
lvDuaas.setItemChecked(position, true);
mAction = getActivity().startActionMode(modeCallBack);
view.setSelected(true);
return true;
}
});
super.onActivityCreated(savedInstanceState);
}
ActionMode.Callback modeCallBack = new ActionMode.Callback() {
@Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
// TODO Auto-generated method stub
mode.getMenuInflater().inflate(R.menu.activity_main, menu);
return false;
}
@Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
// TODO Auto-generated method stub
return false;
}
@Override
public boolean onActionItemClicked(ActionMode mode,
MenuItem item) {
// TODO Auto-generated method stub
switch (item.getItemId()) {
case R.id.delete:
// Calls getSelectedIds method from ListViewAdapter Class
SparseBooleanArray selected = duasAdapter
.getSelectedIds();
// Captures all selected ids with a loop
for (int i = (selected.size() - 1); i >= 0; i--) {
if (selected.valueAt(i)) {
String selecteditem = duasAdapter.getItem(selected.keyAt(i));
// Remove selected items following the ids
duasAdapter.remove(selecteditem);
}
}
// Close CAB
mode.finish();
return true;
default:
return false;
}
}
@Override
public void onDestroyActionMode(ActionMode mode) {
// TODO Auto-generated method stub
duasAdapter.removeSelection();
}
};
}
XML file
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
>
<item
android:id="@+id/delete"
android:title="@string/delete"
/>
</menu>
回答1:
From looking at your code I can see the onCreateActionMode callback function returns false.
onCreateActionMode should return true if the action mode should be created, false if entering this mode should be aborted.
So when the user long clicks on the ListItem and the event is triggered it reaches onCreateActionMode and returns false. Telling it to abort. Hence no CAB menu appears. Try changing it to true and also adding in some logs to see if it ever makes it into the callback function.
This would be the change below:
@Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
// TODO Auto-generated method stub
Log.d("Test","In onCreateActionMode");
mode.getMenuInflater().inflate(R.menu.activity_main, menu);
return true;//code updated here
}
Android Link to reference : http://developer.android.com/reference/android/view/ActionMode.Callback.html#onCreateActionMode(android.view.ActionMode, android.view.Menu)
来源：https://stackoverflow.com/questions/24358733/android-contextual-action-bar-not-appearing-after-item-selection