我尝试将一个字符串从 VC1 传递到 VC2，但是传递到属性 detailItem 的 tex 值只加载到 viewdidload，而不是函数中
View Controller 1:
@IBOutlet var tex: UITextField!
// Prepare fore segue pass the value of txt
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier? == "Todo" {
let navVC = segue.destinationViewController as UINavigationController
let itemVC: ChecklistViewController = navVC.topViewController as ChecklistViewController
itemVC.detailItem! = tex.text
}
}
View Controller 2:
var detailItem : String!
// I can see the value of tex only in the ViewDidLoad
override func viewDidLoad() {
super.viewDidLoad()
println("viewDidLoad \(detailItem)")
tableView.rowHeight = 44
}
// Here and in the function below result nil.
required init(coder aDecoder: NSCoder) {
println("print init \(detailItem)")
items = [ChecklistItem]()
super.init(coder: aDecoder)
loadChecklistItems()
}
func documentsDirectory() -> String {
let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true) as [String]
return paths[0]
}
func dataFilePath() -> String {
println("print path\(detailItem)")
return documentsDirectory().stringByAppendingPathComponent("Checklists.plist")
}
func saveChecklistItems() {
let data = NSMutableData()
let archiver = NSKeyedArchiver(forWritingWithMutableData: data)
archiver.encodeObject(items, forKey: "ChecklistItems")
archiver.finishEncoding()
data.writeToFile(dataFilePath(), atomically: true)
println("print save\(detailItem)")
}
func loadChecklistItems() {
let path = dataFilePath()
if NSFileManager.defaultManager().fileExistsAtPath(path) {
if let data = NSData(contentsOfFile: path) {
println("print load\(detailItem)")
let unarchiver = NSKeyedUnarchiver(forReadingWithData: data)
items = unarchiver.decodeObjectForKey("ChecklistItems") as [ChecklistItem]
unarchiver.finishDecoding()
}
}
}
控制台输出:
print init
print path
print load
viewDidLoad Antwerp
谢谢阿尔贝托
最佳答案
原因是因为当 prepareForSegue 被调用时你的 viewcontroller 2 已经被创建并且 viewDidLoad 已经被调用。
查看 This Link因为它对 View 生命周期有很好的描述
关于ios - SWIFT - 在 viewdidload 之外看不到属性(property)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/29394337/