我根据用户登录状态设定了两个菜单模板文件，自动判断使用其一，其中已经使用了display函数。
这个菜单模板显示和页面主体模板显示是分开的。但是这样使用就会报错。
错误

[2] Cannot modify header information - headers already sent by (output started at /Users/Patrick_Xing/Google 云端硬盘/www/makesonice/ThinkPHP/Library/Think/View.class.php:95) /Users/Patrick_Xing/Google 云端硬盘/www/makesonice/ThinkPHP/Library/Think/View.class.php 第 91 行.
[2] Cannot modify header information - headers already sent by (output started at /Users/Patrick_Xing/Google 云端硬盘/www/makesonice/ThinkPHP/Library/Think/View.class.php:95) /Users/Patrick_Xing/Google 云端硬盘/www/makesonice/ThinkPHP/Library/Think/View.class.php 第 92 行.
[2] Cannot modify header information - headers already sent by (output started at /Users/Patrick_Xing/Google 云端硬盘/www/makesonice/ThinkPHP/Library/Think/View.class.php:95) /Users/Patrick_Xing/Google 云端硬盘/www/makesonice/ThinkPHP/Library/Think/View.class.php 第 93 行.

请问这种情况用啥方法比较合适？