1、配置信息如下：
'URL_MODEL' => 1,
'URL_PARAMS_BIND' => true,
'URL_PARAMS_BIND_TYPE' => 0,

2、定义Controller如下：
<?php
namespace Home\Controller;

use Think\Controller;

class IndexController extends Controller
{
public function index($flag)
{
echo $flag;
}
}

3、在URL输入
http://server_name/admin.php/home/index/flag/2

4、报错
非法操作:flag
错误位置
FILE: /data1/www/htdocs/134/qbabytk/1/ThinkPHP/Library/Think/Controller.class.php 　LINE: 170
TRACE
#0 /data1/www/htdocs/134/qbabytk/1/ThinkPHP/Library/Think/Controller.class.php(170): E('????????????:fl...')
#1 [internal function]: Think\Controller->__call('flag', '')
#2 /data1/www/htdocs/134/qbabytk/1/ThinkPHP/Library/Think/App.class.php(180): ReflectionMethod->invokeArgs(object(Home\Controller\IndexController), Array)
#3 /data1/www/htdocs/134/qbabytk/1/ThinkPHP/Library/Think/App.class.php(202): Think\App::exec()
#4 /data1/www/htdocs/134/qbabytk/1/ThinkPHP/Library/Think/Think.class.php(120): Think\App::run()
#5 /data1/www/htdocs/134/qbabytk/1/ThinkPHP/ThinkPHP.php(97): Think\Think::start()
#6 /data1/www/htdocs/134/qbabytk/1/admin.php(14): require('/data1/www/htdo...')
#7 {main}
ThinkPHP3.2.3 { Fast & Simple OOP PHP framework } -- [ WE CAN DO IT JUST THINK ]

5、求助
这是什么原因？？？