Question

我有一个注册PaymentAddressTableViewCell的UITableView，它有一个名为validate的方法，它查看cellType枚举，并对单元格中的文本字段应用特定的验证。

let tableView = UITableView()
tableView.register(PaymentAddressTableViewCell.self, forCellReuseIdentifier: "PaymentAddressCell")
tableView.dataSource = self
tableView.delegate = self
... more layout

我在Fabric中看到有时下面的演员会失败。到目前为止，我已将其归结为UIKit内部失败的内容。它也可能是对行号的误报，因为应用程序是为生产而编译的。但是为了这个，让我们假设它不是。

我开始将力展开更改为guard let，如下所示。那个案子应该永远不会真的发生。施法非常简单......

for i in [0, 1, 2, 3, 4] {
    let indexPath = IndexPath(row: i, section: 1)
    guard let cell = tableView.cellForRow(at: indexPath) as? PaymentAddressTableViewCell else {
        ... this should never really be hit
    }
}

知道这可能是什么，或者我如何避免演员失败？

谢谢

修改 cellForRowAtIndexPath代码

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "PaymentAddressCell") as! PaymentAddressTableViewCell
    cell.textField?.returnKeyType = .done
    cell.textField?.delegate = self

    switch (indexPath.section, indexPath.row) {
    case (0, 0):
        cell.fieldType = .cardNumber
        cell.textField?.placeholder = "5555123456789999"
        cell.textField?.keyboardType = .numberPad
        cell.textField?.addTarget(self, action: #selector(cardNumberChanged(_:)), for: .editingChanged)
    case (0, 1):
        cell.fieldType = .expiration
        cell.textField?.placeholder = "01/20"
    case (0, 2):
        cell.fieldType = .cvv
        cell.textField?.placeholder = "CVV"
        cell.textField?.keyboardType = .numberPad
        cell.textField?.addTarget(self, action: #selector(cvvChanged(_:)), for: .editingChanged)
    case (1, 0):
        cell.fieldType = .address
        cell.textField?.placeholder = "123 Main Street"
        cell.textField?.autocapitalizationType = .words
        cell.textField?.keyboardType = .default
    case (1, 1): // address line 2
        cell.textField?.placeholder = "Apt 3"
        cell.textField?.autocapitalizationType = .words
        cell.textField?.keyboardType = .default
    case (1, 2):
        cell.fieldType = .city
        cell.textField?.placeholder = "City"
        cell.textField?.autocapitalizationType = .words
        cell.textField?.keyboardType = .default
    case (1, 3):
        let dict: [(key: String, value: String)] = viewModel.statePickerOptions.sorted(by: {
            return $0.0 < $1.0
        })
        cell.textField?.placeholder = "State"
        cell.statesDataSource = dict
        cell.fieldType = .state
    case (1, 4):
        cell.fieldType = .zipcode
        cell.textField?.placeholder = "Zipcode"
        cell.textField?.keyboardType = .numberPad
    default: break
    }

    return cell
}

简单的UITableViewCell转换会间歇性地失败

0 个答案: