core.go

package middleware

import (
    "github.com/gin-gonic/gin"
    "net/http"
)

func Cors() gin.HandlerFunc {
    return func(c *gin.Context) {
        origin := c.Request.Header.Get("Origin") // 请求头部
        if origin != "" {
            // 接收客户端发送的origin
            c.Writer.Header().Set("Access-Control-Allow-Origin", origin)
            //服务器支持的所有跨域请求的方法
            c.Header("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS, HEAD")
            //允许跨域设置可以返回其他子段，可以自定义字段
            c.Header("Access-Control-Allow-Headers", "Origin, Content-Length, Content-Type, Authorization, Cookie, Set-Cookie")
            // 允许浏览器（客户端）可以解析的头部
            c.Header("Access-Control-Expose-Headers", "Content-Length, Content-Type, Access-Control-Allow-Origin, Access-Control-Allow-Headers")
            //设置缓存时间
            c.Header("Access-Control-Max-Age", "172800")
            //允许客户端传递校验信息比如 cookie
            c.Header("Access-Control-Allow-Credentials", "true")
        }
        if c.Request.Method == "OPTIONS" {
            c.AbortWithStatus(http.StatusNoContent)
            return
        }
        c.Next()
    }
}

router.go

    r := gin.New()
    // 跨域
    r.Use(middleware.Cors()) // 开启中间件，允许实现跨域请求
}