No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:3333' is therefore not allowed access. The response had HTTP status code 404.

所以我认为这是一个CORS问题.如何在凤凰中发送标题？

这是我的router.ex

scope "/api",MyApp do
    pipe_through :api
    # Users
    post "/users/register",UserController,:register
  end

这是我的UserController

defmodule MyApp.UserController do
  use MyApp.Web,:controller

  def register(conn,params) do
    IO.puts(inspect(params))

    conn
    |> put_status(201)
    |> json  %{ok: true,data: params}
  end

end