GridView.getCheckedItemPositions（）不返回正确的值

Question

我正在制作一个可以选择/取消选择图像的应用程序。 ，当我选择所有图像一次

GridView.getCheckedItemPositions()会返回正确的值。但如果我取消选择任何项目，此方法不会返回更新的值。

这是我的代码。

gridView.setOnItemClickListener(new OnItemClickListener() {
@Override
            public void onItemClick(AdapterView<?> arg0, View view, int position,
                    long id) {
                //Toast.makeText(GalleryImages.this, "position"+position, Toast.LENGTH_SHORT).show();
                ActionMode mode =startActionMode(mActionModeCallback);
                 mode.setTitle(gridView.getCheckedItemCount() + " Selected");
                 Toast.makeText(GalleryImages.this, ""+gridView.getCheckedItemPositions().size(), Toast.LENGTH_SHORT).show();
            }
        });

final ActionMode.Callback mActionModeCallback = new ActionMode.Callback() {

            @Override
            public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
                // TODO Auto-generated method stub
                return false;
            }

            @Override
            public void onDestroyActionMode(ActionMode mode) {
                mode=null;
            }

            @Override
            public boolean onCreateActionMode(ActionMode mode, Menu menu) {
                // TODO Auto-generated method stub
                getMenuInflater().inflate(R.menu.contextual_menu, menu);

                return true;
            }

            @Override
            public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
                layoutForAlertDialog = (LayoutInflater) GalleryImages.this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                View view = layoutForAlertDialog.inflate(R.layout.addtag_dialog, null);
                alertForTag = new AlertDialog.Builder(GalleryImages.this);
                alertForTag.setTitle("Enter Name Tag");
                alertForTag.setView(view);
                alertForTag.create();
                alertForTag.setCancelable(false).setPositiveButton("OK", new OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {

                    }
                });
                alertForTag.show();
                return true;
            }

        };