在我的Android应用程序中，我试图在列表视图中显示上下文操作栏（CAB）以删除项目。问题是每当按下一个项目很长时，该项目就会被选中，但CAB不会出现。我已经验证了这么多教程，无法弄清楚我错过了什么。任何帮助，将不胜感激。
适配器类
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;
}
}
片段类
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文件
<?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>
答案 0 :(得分：1)
从查看代码我可以看到 onCreateActionMode 回调函数返回false。
如果应该创建动作模式，onCreateActionMode应该返回true，如果应该中止进入这种模式，则返回false。
因此，当用户长按ListItem并触发事件时，它会到达 onCreateActionMode 并返回false。告诉它中止。因此，不会出现CAB菜单。尝试将其更改为true，并添加一些日志以查看它是否进入回调函数。
这将是以下变化：
@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链接参考：http://developer.android.com/reference/android/view/ActionMode.Callback.html#onCreateActionMode(android.view.ActionMode，android.view.Menu）