Question

我想在收到服务器的回复后更改我的标签文字，但在收到服务器的回复后它没有改变!!

这是我的代码：

func getOrderCost() {

    DispatchQueue.main.async {

        self.customView?.setOrderPriceEstimate(price: "۰")
        var price = 10
        if let p_code = self.customView?.getPromotionCode() {

            self.orderPriceObject.promotion_code = p_code
        }  
        self.registerOrderVM.getOrderPriceEstimation(orderInfo: self.orderPriceObject).asObservable().subscribe(onNext: { (response) in

            if let res = response as? [String: Int], let p = res["price_with_added_value"] {

                self.customView?.setOrderPriceEstimate(price: "cost : \(p)")
            }
        }, onError: { (error) in

            self.view.showMessage(error.localizedDescription, type: .error, options: [.hideOnTap(true)])
        }).disposed(by: self.disposeBag)
    }
}

这是setOrderPriceEstimate中的customView函数：

public func setOrderPriceEstimate(price: String) {

    self.orderCostLbl.text = price
}

Answer 1

使 DispatchQueue.main.async 外部并不保证 getOrderPriceEstimation 中的代码将在主队列中运行，因为getOrder中的代码可能位于其他线程中

    func getOrderCost() {
        DispatchQueue.main.async {
            self.customView?.setOrderPriceEstimate(price: "۰")
            var price = 10
            if let p_code = self.customView?.getPromotionCode() {
                self.orderPriceObject.promotion_code = p_code
            }



            self.registerOrderVM.getOrderPriceEstimation(orderInfo: self.orderPriceObject).asObservable().subscribe(onNext: { (response) in


                if let res = response as? [String: Int], let p = res["price_with_added_value"] {

              DispatchQueue.main.async {
                    self.customView?.setOrderPriceEstimate(price: "cost : \(p)")

                  }
                }

            }, onError: { (error) in

                self.view.showMessage(error.localizedDescription, type: .error, options: [.hideOnTap(true)])
            }).disposed(by: self.disposeBag)

        }

    }

验证是否存在p

if let res = response as? [String: Int], let p = res["price_with_added_value"] {

                  DispatchQueue.main.async {
                self.customView?.setOrderPriceEstimate(price: "cost : \(p)")          }
            }
     else
    {
       print("res or p is not found")
    }

同时检查customView是否为nil

Answer 2

DispatchQueue.main.async {
        self.customView?.setOrderPriceEstimate(price: "cost : \(p)")
    }

我认为你必须在主线程中更新UI。

标签在回调swift 3中没有变化

2 个答案: