mSearchMenuItem.setOnActionExpandListener(new OnActionExpandListener() {
             
            @Override
            public boolean onMenuItemActionExpand(MenuItem item) {
                // TODO Auto-generated method stub
                return true;
            }
             
            @Override
            public boolean onMenuItemActionCollapse(MenuItem item) {
                mAdapter.getFilter().filter("");
                return true;
            }
        });

参考链接:1