public function index()
{
if (Auth::user()->hasRole("admin")) {
$users = User::all();
$demands = Demand::all();
$bids = Bid::all();
$counts['user'] = count($users);
$counts['demand'] = count($demands);
$counts['bid'] = count($bids);
return view('admin.index')->with('counts', $counts);
} else {
return redirect()->back()->withInput()->withErrors('您不是管理员，无法进行此操作。');
}
}
