所以,我使用rails-api创建了我的第一个项目,并添加了以下代码：

在MyProject中的routes.rb>配置目录

MyProject::Application.routes.draw do
    namespace :api,defaults: {format: 'json'} do
        namespace :v1 do
            resources :users
        end
    end
end

MyProject中的users_controller.rb> app>控制器> api> v1>用户目录

module Api
    module V1
        class UsersController < ApplicationController
            def index
            end

            def create
            end

            def show
            end

            def update
            end

            def delete
            end
        end 
    end
end

当我使用命令行rails s启动rails服务器并转到此URL：http：// localhost：3000 / api / v1 / users / show我遇到此错误：

uninitialized constant Api::V1::UsersController

Rails.root: /Users/Jean/Development/MyProject

Application Trace | Framework Trace | Full Trace activesupport (4.0.4)@H_403_20@ lib/active_support/inflector/methods.rb:228:in const_get'@H_403_20@ activesupport (4.0.4) lib/active_support/inflector/methods.rb:228:in@H_403_20@ block in constantize’ activesupport (4.0.4)@H_403_20@ lib/active_support/inflector/methods.rb:224:in each' activesupport@H_403_20@ (4.0.4) lib/active_support/inflector/methods.rb:224:ininject’@H_403_20@ activesupport (4.0.4) lib/active_support/inflector/methods.rb:224:in@H_403_20@ constantize' actionpack (4.0.4)@H_403_20@ lib/action_dispatch/routing/route_set.rb:76:incontroller_reference’@H_403_20@ actionpack (4.0.4) lib/action_dispatch/routing/route_set.rb:66:in@H_403_20@ controller' actionpack (4.0.4)@H_403_20@ lib/action_dispatch/routing/route_set.rb:44:incall’ actionpack@H_403_20@ (4.0.4) lib/action_dispatch/journey/router.rb:71:in block in call'@H_403_20@ actionpack (4.0.4) lib/action_dispatch/journey/router.rb:59:ineach’@H_403_20@ actionpack (4.0.4) lib/action_dispatch/journey/router.rb:59:in call'@H_403_20@ actionpack (4.0.4) lib/action_dispatch/routing/route_set.rb:674:in@H_403_20@ call’ rack (1.5.2) lib/rack/etag.rb:23:in call' rack (1.5.2)@H_403_20@ lib/rack/conditionalget.rb:25:incall’ rack (1.5.2)@H_403_20@ lib/rack/head.rb:11:in call' actionpack (4.0.4)@H_403_20@ lib/action_dispatch/middleware/params_parser.rb:27:incall’@H_403_20@ activerecord (4.0.4) lib/active_record/query_cache.rb:36:in call'@H_403_20@ activerecord (4.0.4)@H_403_20@ lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in@H_403_20@ call’ activerecord (4.0.4) lib/active_record/migration.rb:373:in@H_403_20@ call' actionpack (4.0.4)@H_403_20@ lib/action_dispatch/middleware/callbacks.rb:29:inblock in call’@H_403_20@ activesupport (4.0.4) lib/active_support/callbacks.rb:373:in@H_403_20@ _run__4323212420903942114__call__callbacks' activesupport (4.0.4)@H_403_20@ lib/active_support/callbacks.rb:80:inrun_callbacks’ actionpack@H_403_20@ (4.0.4) lib/action_dispatch/middleware/callbacks.rb:27:in call'@H_403_20@ actionpack (4.0.4) lib/action_dispatch/middleware/reloader.rb:64:in@H_403_20@ call’ actionpack (4.0.4)@H_403_20@ lib/action_dispatch/middleware/remote_ip.rb:76:in call' actionpack@H_403_20@ (4.0.4) lib/action_dispatch/middleware/debug_exceptions.rb:17:in@H_403_20@ call’ actionpack (4.0.4)@H_403_20@ lib/action_dispatch/middleware/show_exceptions.rb:30:in call'@H_403_20@ railties (4.0.4) lib/rails/rack/logger.rb:38:incall_app’ railties@H_403_20@ (4.0.4) lib/rails/rack/logger.rb:20:in block in call' activesupport@H_403_20@ (4.0.4) lib/active_support/tagged_logging.rb:68:inblock in tagged’@H_403_20@ activesupport (4.0.4) lib/active_support/tagged_logging.rb:26:in@H_403_20@ tagged' activesupport (4.0.4)@H_403_20@ lib/active_support/tagged_logging.rb:68:intagged’ railties (4.0.4)@H_403_20@ lib/rails/rack/logger.rb:20:in call' actionpack (4.0.4)@H_403_20@ lib/action_dispatch/middleware/request_id.rb:21:incall’ rack (1.5.2)@H_403_20@ lib/rack/runtime.rb:17:in call' activesupport (4.0.4)@H_403_20@ lib/active_support/cache/strategy/local_cache.rb:83:incall’ rack@H_403_20@ (1.5.2) lib/rack/lock.rb:17:in call' actionpack (4.0.4)@H_403_20@ lib/action_dispatch/middleware/static.rb:64:incall’ railties (4.0.4)@H_403_20@ lib/rails/engine.rb:511:in call' railties (4.0.4)@H_403_20@ lib/rails/application.rb:97:incall’ rack (1.5.2)@H_403_20@ lib/rack/lock.rb:17:in call' rack (1.5.2)@H_403_20@ lib/rack/content_length.rb:14:incall’ rack (1.5.2)@H_403_20@ lib/rack/handler/webrick.rb:60:in service'@H_403_20@ /Users/Jean/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/webrick/httpserver.rb:138:in@H_403_20@ service’@H_403_20@ /Users/Jean/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/webrick/httpserver.rb:94:in@H_403_20@ run'@H_403_20@ /Users/Jean/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/webrick/server.rb:295:in@H_403_20@ block in start_thread’

我发现Stackoverflow上有很多帖子有相同的错误,但答案并没有帮助我解决我的问题.

谢谢 ！