Ruby on rails 添加发送消息链接时显示ActiveRecord\u关联的rails出错

我有一个rails应用程序，用户可以在其中添加帖子，其他用户可以对其进行评论。我试图添加一个与评论用户的直接消息链接，我在stackoverflow的建议下尝试了类似的方法

\u form.html.erb

<%= form_for :conversation, url: :conversations, html: { class: "" } do |f| %>
<div class="form-group">
  <%= f.label :recipients %>
  <%= hidden_field_tag(:recipient_id, "#{@user.id}") %></div>
<div class="form-group">
  <%= f.label :subject %>
  <%= f.text_field :subject, placeholder: "Subject", class: "form-control" %>
</div>
<div class="form-group">
  <%= f.label :message %>
  <%= f.text_area :body, class: 'form-control',placeholder: "Type your message here", rows: 4  %>
</div>

<%= f.submit "Send Message", class: "btn btn-success" %>

<% end %>

<%= link_to 'Send Message', new_conversation_path(:recipient_id => @post.comments.user.id), class: 'send-message-icon' %>

**conversation_controller.rb**
def new
    @user = User.find_by(id: params[:recipient_id])
  end

   def create
    recipients = User.find_by(id: params[:recipient_id])
    conversation = current_user.send_message(recipients, conversation_params[:body], conversation_params[:subject]).conversation
    flash[:success] = "Your message was successfully sent!"
    respond_to do |format|
      format.html {redirect_to conversation_path(conversation)}
      format.js
    end
  end

show.html.erb

<%= form_for :conversation, url: :conversations, html: { class: "" } do |f| %>
<div class="form-group">
  <%= f.label :recipients %>
  <%= hidden_field_tag(:recipient_id, "#{@user.id}") %></div>
<div class="form-group">
  <%= f.label :subject %>
  <%= f.text_field :subject, placeholder: "Subject", class: "form-control" %>
</div>
<div class="form-group">
  <%= f.label :message %>
  <%= f.text_area :body, class: 'form-control',placeholder: "Type your message here", rows: 4  %>
</div>

<%= f.submit "Send Message", class: "btn btn-success" %>

<% end %>

<%= link_to 'Send Message', new_conversation_path(:recipient_id => @post.comments.user.id), class: 'send-message-icon' %>

**conversation_controller.rb**
def new
    @user = User.find_by(id: params[:recipient_id])
  end

   def create
    recipients = User.find_by(id: params[:recipient_id])
    conversation = current_user.send_message(recipients, conversation_params[:body], conversation_params[:subject]).conversation
    flash[:success] = "Your message was successfully sent!"
    respond_to do |format|
      format.html {redirect_to conversation_path(conversation)}
      format.js
    end
  end

@post.comments.user.id），类：“发送消息图标”%>
**会话_controller.rb**
def新
@user=user.find_by（id:params[：recipient_id]）
结束
def创建
recipients=User.find_by（id:params[：recipient_id]）
会话=当前用户。发送消息（收件人、会话参数[：正文]、会话参数[：主题]）。会话
flash[：success]=“您的邮件已成功发送！”
回应待办事项|格式|
format.html{重定向到对话路径（对话）}
format.js
结束
结束

但是我得到了以下错误

undefined method `user' for #<Comment::ActiveRecord_Associations_CollectionProxy:0x93b1018>

的未定义方法“user”#

---

我正在使用mailboxer gem来实现消息传递功能。

假设您有一个

注释

表，其中有一列

用户id

<% @post.comments.each do |comment| %>
  <%= link_to 'Send Message', new_conversation_path(recipient_id: comment.user_id) %>