按照官网给出的例子，在中间件配置允许跨域
app/middleware.php
<?php // 中间件配置 use think\middleware\AllowCrossDomain; return [ AllowCrossDomain::class ];
前端请求依然出现了跨域请求提示
Access to XMLHttpRequest at from origin has been blocked by CORS policy: Request header field x-token is not allowed by Access-Control-Allow-Headers in preflight response.
原因是我们添加了自定义的请求头X-Token用来携带token，所以需要我们重新改造一下中间件
新建一个自定义的跨域中间件
app/middleware/AllowCrossDomainMiddleware.php
<?php namespace app\middleware; use think\middleware\AllowCrossDomain; class AllowCrossDomainMiddleware extends AllowCrossDomain { // 加入自定义请求头参数 X-Token protected $header = [ 'Access-Control-Allow-Credentials' => 'true', 'Access-Control-Max-Age' => 1800, 'Access-Control-Allow-Methods' => 'GET, POST, PATCH, PUT, DELETE, OPTIONS', 'Access-Control-Allow-Headers' => 'Authorization, Content-Type, If-Match, If-Modified-Since, If-None-Match, If-Unmodified-Since, X-CSRF-TOKEN, X-Requested-With, X-Token', ]; }
重新配置中间件
app/middleware.php
<?php // 中间件配置 use think\middleware\AllowCrossDomain; use app\middleware\AllowCrossDomainMiddleware; return [ // 不使用默认的跨域中间件 // AllowCrossDomain::class // 使用自定义跨域中间件 AllowCrossDomainMiddleware::class ];
继续改进
查看请求日志发现，options请求会走一遍处理流程，有些需要权限校验的地方还会因为缺少参数而报错，这样肯定不行。
可以在入口文件添加以下代码，单独处理options请求
public/index.php
// 处理 OPTIONS 请求 if($_SERVER['REQUEST_METHOD'] == 'OPTIONS'){ header("'Access-Control-Allow-Credentials: true"); header("Access-Control-Allow-Origin: *"); header("Access-Control-Allow-Headers: Authorization, Content-Type, If-Match, If-Modified-Since, If-None-Match, If-Unmodified-Since, X-CSRF-TOKEN, X-Requested-With, X-Token"); header('Access-Control-Allow-Methods: GET, POST, PUT, DELETE, OPTIONS, PATCH'); exit; // 直接退出，不走后序流程 }
添加了发现有的接口还是会有跨域问题存在, POST方式漏处理了，再次优化如下
// 添加允许跨域请求头 header("'Access-Control-Allow-Credentials: true"); header("Access-Control-Allow-Origin: *"); header("Access-Control-Allow-Headers: Authorization, Content-Type, If-Match, If-Modified-Since, If-None-Match, If-Unmodified-Since, X-CSRF-TOKEN, X-Requested-With, X-Token"); header('Access-Control-Allow-Methods: GET, POST, PUT, DELETE, OPTIONS, PATCH'); // 处理 OPTIONS 请求 if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') { exit; }
