小编Muk*_*esh的帖子

我想定制以下内容

1. 操作名称如"添加用户"=>"创建用户","编辑用户"=>"更新用户"等
2. 成功消息删除,创建和编辑,如"用户成功创建"=>"客户已成功创建"
3. 在编辑和删除旁边的显示页面上添加创建按钮

我想创建一个partials来为DRY的不同命名空间在索引面板中呈现一些数据

我现在正在写作

 index do
    render 'index', user: :user    
 end
//_index.html.arb
column :id
column 'Customer Name', :name
column :mobile
column :recipient_number    
column :cash_in_hand do |customer|
  number_to_currency(customer.cash_in_hand, unit: "\u20B9", precision: 2)
end
column "Due Balance" do |customer|      
  number_to_currency(customer.due_balance, unit: "\u20B9", precision: 2)
end
actions

这不起作用(抛出Nullpointer异常)

String s =  null; 
System.out.println(s); 
System.out.println(String.valueOf(null));

但这是

String s =  null; 
System.out.println(s); 
System.out.println(String.valueOf(s));

为什么？无法得到.我想了解背后的逻辑.

我的标准代码

class Bank < ApplicationRecord
    has_one :address
    accepts_nested_attributes_for :address
end



 class Address < ApplicationRecord
    belongs_to :bank
 end

我的控制器

def create
    @bank = Bank.new(bank_params)

    respond_to do |format|
      if @bank.save
        format.html { redirect_to @bank, notice: 'Bank was successfully created.' }
        format.json { render :show, status: :created, location: @bank }
      else
        format.html { render :new }
        format.json { render json: @bank.errors, status: :unprocessable_entity }
      end
    end
end

def bank_params
      params.require(:bank).permit(:code, :currency, :name, :mobile_1, :mobile_2, :email, address_attributes: [:id, :name, :area, :pin_code, :city_id] )
end …