TableView多个单元不工作，由于信号9而终止

Question

我想让tabbaritem点击call api并填充tableView。但在我的例子中，我不得不使用多个cell。

 up category (tab bar item)  -> category (1- cell) -> products (2- cell)
 up category (tab bar item)-> products (2- cell)

我在tableView中有两个原型单元。显示类别的第一个单元格。第二个单元格用于显示产品。当分类点击时，我重新加载了tableview，然后我就可以显示产品了。但是当我只展示了一次产品时。我的表视图不可用。我确定我调用了reload data。来自调试器的消息:由于信号9而终止这是我的代码，

 func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
    if let orderType = selectedOrderType
    {
        switch orderType
        {
            case OrderViewHelper.OrderType.Category:
                  return self.categories.count;
            case OrderViewHelper.OrderType.Menu:
                  return self.menus.count;
            case OrderViewHelper.OrderType.Product:
                  return self.products.count;
        }
    }
    return 0;
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
    var returnerCell = UITableViewCell();
    switch selectedOrderType!
    {
        case OrderViewHelper.OrderType.Category:
                let cell = tableView.dequeueReusableCell(withIdentifier: ViewCellStatics.TABLE_ORDER_VIEW_CELL, for: indexPath) as! CategoryTableViewCell;
                cell.lblCategoryId.text = self.categories[indexPath.row].Id;
                cell.lblCategoryName.text = self.categories[indexPath.row].Name;
                cell.lblCategoryId.isHidden = true;
                returnerCell = cell;
                break;
        case OrderViewHelper.OrderType.Menu:
            let cell = tableView.dequeueReusableCell(withIdentifier: ViewCellStatics.TABLE_PRODUCT_VIEW_CELL, for: indexPath) as! ProductsTableViewCell;
            cell.lblPrice.text = self.menus[indexPath.row].Price;
            cell.lblProductName.text = self.menus[indexPath.row].Name;
            cell.lblId.text = self.menus[indexPath.row].Id;
            cell.lblId.isHidden = true;
            cell.lblProductName.numberOfLines = 2;
            returnerCell = cell;
            break;
        case OrderViewHelper.OrderType.Product:
            let cell = tableView.dequeueReusableCell(withIdentifier: ViewCellStatics.TABLE_PRODUCT_VIEW_CELL, for: indexPath) as! ProductsTableViewCell;
            cell.lblPrice.text = self.products[indexPath.row].Price;
            cell.lblProductName.text = self.products[indexPath.row].Name;
            cell.lblId.text = self.products[indexPath.row].Id;
            cell.lblId.isHidden = true;
            cell.lblProductName.numberOfLines = 2;
            cell.addButton.Model = self.products[indexPath.row];
            cell.addButton.addTarget(self, action: #selector(addBasket(_:)), for: .touchUpInside);
            break;
    }
    return returnerCell;
}



private func getCategories(upperCategoryId : String)
    {
        var paramaters = [WebServiceParamater]();
        paramaters.append(WebServiceParamater(key: WebServiceVariableKeys.UPPER_CATEGORY, value: upperCategoryId));
        WebService().GetData(action: ActionNames.CATEGORIES, paramater: paramaters)
        {
            (objects) in
            if (objects == nil || objects?.count == 0) { return; }
            self.ClearModels(type: OrderViewHelper.OrderType.Category);
            DispatchQueue.main.sync
            {
                self.categories = JsonParser.ParseCategories(jsonArray: objects);
                self.tableOrders.reloadData();
            }
        }
    }

    private func getProducts(category : CategoryModel)
    {
        var paramaters = [WebServiceParamater]();
        paramaters.append(WebServiceParamater(key: WebServiceVariableKeys.CATEGORY, value: category.Id));
        WebService().GetData(action: ActionNames.PRODUCT, paramater: paramaters)
        {
            (objects) in
            if (objects == nil || objects?.count == 0) { return; }
            self.ClearModels(type: OrderViewHelper.OrderType.Product);
            DispatchQueue.main.sync
            {
                self.products = JsonParser.ParseProduct(jsonArray: objects);
                self.tableOrders.reloadData();
            }
        }
    }

截图

类别

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我点击了一个类别，这样就可以看到产品了

​

​

重新加载数据不起作用。

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Answer 1

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DispatchQueue.main.sync，请尝试调用DispatchQueue.main.async。

顺便说一句:确保WebService中的方法在后台线程中异步调用，这样就不会在加载东西时阻塞UI。

我希望这个答案能帮助你理解https://stackoverflow.com/a/44324968/4304998