跨域设置可以使用官网推荐的插件

github.com/gin-contrib/cors

也可以自己写一个中间件

func Cors() gin.HandlerFunc {
	return func(c *gin.Context) {
		if origin != "" {
			c.Header("Access-Control-Allow-Origin", "*")  // 可将将 * 替换为指定的域名
			c.Header("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE, UPDATE")
			c.Header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, Authorization")
			c.Header("Access-Control-Expose-Headers", "Content-Length, Access-Control-Allow-Origin, Access-Control-Allow-Headers, Cache-Control, Content-Language, Content-Type")
			c.Header("Access-Control-Allow-Credentials", "true")
		}
		c.Next()
	}
}

当然上述的可以进行基本的请求操作。如果修改了header，使用浏览器进行 Get Post Header等请求的话，会默认进行OPTIONS的请求进行试探，要做下处理。

func Cors() gin.HandlerFunc {
	return func(c *gin.Context) {
		method := c.Request.Method
		if origin != "" {
			c.Header("Access-Control-Allow-Origin", "*")  // 可将将 * 替换为指定的域名
			c.Header("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE, UPDATE")
			c.Header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, Authorization")
			c.Header("Access-Control-Expose-Headers", "Content-Length, Access-Control-Allow-Origin, Access-Control-Allow-Headers, Cache-Control, Content-Language, Content-Type")
			c.Header("Access-Control-Allow-Credentials", "true")
		}
		if method == "OPTIONS" {
			c.AbortWithStatus(http.StatusNoContent)
		}
		c.Next()
	}
}

注意的是Access-Control-Allow-Headers和Access-Control-Allow-Methods 值 如果设置不当也会造成跨域问题无法进行访问，可以去掉也可以进行加 * 操作

func Cors() gin.HandlerFunc {
	return func(c *gin.Context) {
		method := c.Request.Method
		if origin != "" {
			c.Header("Access-Control-Allow-Origin", "*")  // 可将将 * 替换为指定的域名
			c.Header("Access-Control-Allow-Methods", "*")
			//c.Header("Access-Control-Allow-Headers", "*")
			c.Header("Access-Control-Expose-Headers", "Content-Length, Access-Control-Allow-Origin, Access-Control-Allow-Headers, Cache-Control, Content-Language, Content-Type")
			c.Header("Access-Control-Allow-Credentials", "true")
		}
		if method == "OPTIONS" {
			c.AbortWithStatus(http.StatusNoContent)
		}
		c.Next()
	}
}