Question

如果我只是想通过代码设置标签，我应该写这样的例子，

let label = UILabel()
label.frame = CGRect(x:10, y:   10, width:160, height:30)
label.text = "Test"
self.view.addSubview(label)

但如果我想在tableView的单元格中设置标签，我该如何设置呢？

谢谢！

Answer 1

UITableviewCell子类具有textlabel属性，您可以使用

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell", for: indexPath) as! CustomTableViewCell
    let label = UILabel()
    label.frame = CGRect(x: 10, y: 10, width: 160, height: 30)
    label.text = "Test"
    cell.contentView.addSubview(label)
    return cell
}

或者您可以使用自定义单元格进行更多控制

class OrdersController < ApplicationController
  before_action :set_order, only: [:show, :edit, :update, :destroy]
  before_action :authenticate_user!, :except => [:notify]
  skip_before_action :verify_authenticity_token
  protect_from_forgery :except => [:notify]

  def sales
    @orders = Order.all.where(seller: current_user).order("created_at DESC")
  end

  def purchases
    @orders = Order.all.where(buyer: current_user).order("created_at DESC")
  end

  # GET /orders/new
  def new
    @order = Order.new
    @item = Item.find(params[:item_id])
  end

  # POST /orders
  # POST /orders.json
  def create
    @@order = Order.new(order_params)
    @item = Item.find(params[:item_id])
    @seller = @item.user

    @@order.item_id = @item.id
    @@order.buyer_id = current_user.id
    @@order.seller_id = @seller.id

    # p = Print.find_by(id: params[:id])
    # creator = Creator.find_by(id: p.creator_id)
    price = (@item.price + @item.shipping_price.to_i)
    commission = 0.06

    # Build API call
    @api = PayPal::SDK::AdaptivePayments.new
    @pay = @api.build_pay({
      :actionType => "PAY",
      :cancelUrl => "http://f4bd4637.ngrok.io" + new_item_order_path,
      :returnUrl => root_url,
      :currencyCode => "USD",
      :feesPayer => "PRIMARYRECEIVER",
      :ipnNotificationUrl => "http://f4bd4637.ngrok.io" + paypal_ipn_notify_path,
      :receiverList => {
        :receiver => [
          {
            :amount => price,
            :email => @@order.item.paypal_email,
            :primary => true
          },
          {
            :amount => price * commission,
            :email => "example@gmail.com",
            :primary => false
          }
        ]
      }})

   # Make API call
    @pay_response = @api.pay(@pay)

    # Check if call was valid, if so, redirect to PayPal payment url
    if @pay_response.success?
      @pay_response.payKey
      redirect_to @api.payment_url(@pay_response)
    else
      redirect_to root_path, alert: @pay_response.error[0].message
    end

  end

  def notify
    response = validate_IPN_notification(request.raw_post)
    case response
    when "VERIFIED"
      @@order.save
    when "INVALID"
    else
    end
    render :nothing => true
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_order
      @order = Order.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def order_params
      if params[:orders] && params[:orders][:stripe_card_token].present?
        params.require(:orders).permit(:stripe_card_token)
      end
    end

  protected
  def validate_IPN_notification(raw)
    uri = URI.parse('https://ipnpb.sandbox.paypal.com/cgi-bin/webscr?cmd=_notify-validate')
    http = Net::HTTP.new(uri.host, uri.port)
    http.open_timeout = 60
    http.read_timeout = 60
    http.verify_mode = OpenSSL::SSL::VERIFY_NONE
    http.use_ssl = true
    response = http.post(uri.request_uri, raw,
                         'Content-Length' => "#{raw.size}",
                         'User-Agent' => "My custom user agent"
                       ).body
  end

end

Answer 2

您应该为您创建一个自定义类。这会向单元格添加标签，并使用锚定系统在标签上设置约束以填充整个单元格。

class CustomCell: UITableViewCell {
let label: UILabel = {
 let n = UILabel()
     n.textColor = UIColor.darkGray
     n.textAlignment = .center
     n.text = "Testing 123"
     n.font = UIFont(name: "Montserrat", size: 30)
 return n
}()

 override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
    super.init(style: style, reuseIdentifier: reuseIdentifier)

    addSubview(label)

   label.translatesAutoresizingMaskIntoConstraints = false
   label.leftAnchor.constraint(equalTo: leftAnchor).isActive = true
   label.rightAnchor.constraint(equalTo: rightAnchor).isActive = true
   label.topAnchor.constraint(equalTo: topAnchor).isActive = true
   label.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
}

required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}
}

对于使用此自定义单元格的ViewController，您必须添加以下单元格注册，除非您使用的是故事板/界面构建器。

class ControllerUsesCell: UITableViewController {
  let defaultCellId = "cellId"

  override func viewDidLoad() {
   super.viewDidLoad()

    tableView?.register(CustomCell.self, forCellWithReuseIdentifier: defaultCellId)
   }

  }

如何通过代码在tableview的单元格中设置标签？

2 个答案: