如果我使用多个 "if statements" 然后在 swift 中遇到错误（由于未捕获的异常而终止应用程序）

Question

我正在使用 PopoverView 在表格视图单元格按钮中显示选项，例如 this screen shot

这里如果我这样使用没有错误..但是如果用if statements检查条件然后崩溃和错误

 @objc func showOptions(sender:UIButton) {
   
    popoverView?.show(with: ["View", "View Proposal", "Delete"], sender: sender, showDirection: .up)
 }

但是我需要根据以下条件为每个单元格显示不同的选项

单元格按钮操作代码：这里打开，关闭，进行中..都是分段模式

    @objc func showOptions(sender:UIButton) {
   
    if mode == .Open{
        popoverView?.show(with: ["View", "View Proposal", "Delete"], sender: sender, showDirection: .up)
    }
    if (mode == .Open) && (bidsCount > 0){
        popoverView?.show(with: ["View", "View Proposal", "Edit", "Delete"], sender: sender, showDirection: .up)
    }
    if mode == .In_progress{
        popoverView?.show(with: ["View", "View Proposal", "Delete"], sender: sender, showDirection: .up)
    }
    if mode == .Awarded{
        popoverView?.show(with: ["View", "Delete"], sender: sender, showDirection: .up)
    }
    if mode == .Closed{
        popoverView?.show(with: ["View"], sender: sender, showDirection: .up)
    }
}

PopoverView 代码：

extension PageContentViewController: PopoverViewDelegate {
func value(didSelect item: String, at index: Int, indexPath: IndexPath, sender: UIView) {
    if item == "View" {
        let vc = UIStoryboard.init(name: "Main", bundle: Bundle.main).instantiateViewController(withIdentifier: "VC1") as? VC1
        self.navigationController?.pushViewController(vc!, animated: true)
    }
    if item == "View Proposal" {
        let vc = UIStoryboard.init(name: "Main", bundle: Bundle.main).instantiateViewController(withIdentifier: "VC2") as? VC2
        self.navigationController?.pushViewController(vc!, animated: true)
    }
     if item == "Post Review" {
        let vc = UIStoryboard.init(name: "Main", bundle: Bundle.main).instantiateViewController(withIdentifier: "VC3") as? VC3
        self.navigationController?.pushViewController(vc!, animated: true)
    }
}

错误：

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Application tried to present modally a view controller <UITableViewController: 0x7fdb37092420> that is already being presented by <TestApp.SideMenuController: 0x7fdb36659370>.'

Answer 1

if mode == .Open{
    popoverView?.show(with: ["View", "View Proposal", "Delete"], sender: sender, showDirection: .up)
}
if (mode == .Open) && (bidsCount > 0){
    popoverView?.show(with: ["View", "View Proposal", "Edit", "Delete"], sender: sender, showDirection: .up)
}

这会显示一个弹出窗口，然后显示第二个弹出窗口，这是不允许的。任何时候 (mode == .Open) && (bidsCount > 0) 为真，mode == .Open 也为真。

您可能打算重新排序并使用 else if 而不仅仅是 if。

然而，一般来说，这将通过 switch 语句完成，例如：

switch mode {
    case .Open where bidsCount > 0:
        ...
    case .Open:
        ...
    case .In_progress:
        ...
    ...
}

（请注意，在 Swift 中，枚举大小写通常是驼峰式大小写。因此这些通常是 .open 和 .inProgress。）

如果我使用多个 "if statements" 然后在 swift 中遇到错误（由于未捕获的异常而终止应用程序）

If i use multiple "if statements" then hitting error (Terminating app due to uncaught exception) in swift

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