nginx - php yaf配置问题

#nginx.conf
        location /wx
        {
            root /wx/public/index.php;
            if (!-e $request_filename) {
              rewrite ^/wx/(.*)$ /wx/public/index.php?$1 last;
            }
        }

//public/index.php
bootstrap()->run();

#conf/application.ini
[product]
application.directory=APP_PATH "/application/" 
application.dispatcher.catchException = TRUE
application.dispatcher.throwException = TRUE
application.modules=index,admin
application.view.ext = 'php'

为什么这样配置，访问http://localhost/wx会提示

Page was not found
Failed opening controller script /home/wwwroot/default/wx/application/controllers/Wx.php: No such file or directory
#0 /home/wwwroot/default/wx/public/index.php(7): Yaf_Application->run()
#1 {main}

在public/index.php打印$_REQUEST，是个空数组

目录结构：bootstrap.php在zapplication下，入口文件index.php在public下
补充一下，把域名绑定到/home/wwwroot/default/wx，用域名是可以访问的（rewrite规则要对应修改，不是上面那个），rewrite规则改成上面那个，再使用http://ip/wx访问（wx是yaf项目目录），就不行了。会把/wx/当成控制器