Question

目前代码看起来非常粗略：

@NSManaged var property1: NSNumber?
@NSManaged var property2: String?
@NSManaged var property3: NSNumber
@NSManaged var property4: NSNumber?
@NSManaged var property5: Date?

override func setValue(_ value: Any?, ofProperty property: String) -> Bool {
    let undoManager = NSDocumentController.shared().currentDocument?.undoManager
    if property == "property1" {
        undoManager?.registerUndo(withTarget:self, handler: { [oldValue = self.property1] (Node) -> () in
            self.property1 = oldValue
        })
    } else if property == "property2" {
        undoManager?.registerUndo(withTarget:self, handler: { [oldValue = self.property2] (Node) -> () in
            self.property2 = oldValue
        })
    } else if property == "property3" {
        undoManager?.registerUndo(withTarget:self, handler: { [oldValue = self.property3] (Node) -> () in
            self.property3 = oldValue
        })
    } else if property == "property4" {
        undoManager?.registerUndo(withTarget:self, handler: { [oldValue = self.property4] (Node) -> () in
            self.property4 = oldValue
        })
    } else if property == "property5" {
        undoManager?.registerUndo(withTarget:self, handler: { [oldValue = self.property5] (Node) -> () in
            self.property5 = oldValue
        })
    }

优化的直接想法是使用KVC，setValue:forKey:，它将删除我的switch语句（我知道这是一个很大的if / else if块）

但是，这样做会在运行时抛出错误：

[General] [valueForUndefinedKey：]：这个类是密钥通道不符合密钥值编码。

我以前见过这个，我认为这是因为我的属性是@NSManaged，并且没有被ivar支持。虽然我不确定

以前有人见过这个，或者知道我可以优化的方法吗？我只是问，因为实际上有超过20个属性，这样做感觉非常糟糕

如何在属性键上优化此switch语句，理想情况下使用KVC设置@NSManaged属性

0 个答案: