当在同一个 VC 和 VC 中调用 prepareForSegue 包含 tableView 和花药两个 segue 操作按钮时，按钮操作 segue 不起作用

Question

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

    self.selectedIndexPath = indexPath as NSIndexPath

    performSegue(withIdentifier: "toAddToChart", sender: nil)
}



 open override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

    let indexPath = self.selectedIndexPath
    let product = products[indexPath.row]


    if (segue.identifier == "toAddToChart") {
        if  let viewController = segue.destination as? AddToOrderVC  {




        viewController.productName = product.productName
        viewController.productCode = product.productCode
        viewController.productType = product.productType
        viewController.productPrice = product.productPrice
        viewController.productDetails = product.productDescription
        viewController.pImageUrl = product.productimageUrl




    }
}

}

/当我从 viweController 中删除 prepareForSegue 函数时，它会起作用，但是当我应用它并构建代码后，我得到线程 1:signal 当按下另一个动作 segue 按钮时出现 SigBArt 错误

Answer 1

当让 product = products[indexPath.row] 用确认标识符在 segue 的外面调用，它会产生一个错误，所以这个错误是

 open override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

    let indexPath = self.selectedIndexPath



    if (segue.identifier == "toAddToChart") {
        if  let viewController = segue.destination as? AddToOrderVC  {

        let product = products[indexPath.row]

        viewController.productName = product.productName
        viewController.productCode = product.productCode
        viewController.productType = product.productType
        viewController.productPrice = product.productPrice
        viewController.productDetails = product.productDescription
        viewController.pImageUrl = product.productimageUrl




    }
}

}