xcode “IBOutlet”属性具有非可选类型“UIButton”
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'IBOutlet' property has non-optional type 'UIButton'
提问by josmek
Here's my code:
这是我的代码：
import UIKit
class ViewController: UIViewController {
@IBOutlet var button: UIButton
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
It's a simple IBOutlet (straight from the Apple developer docs). It gives me the error "'IBOutlet' property has non-optional type 'UIButton'" and I have no idea how to fix it.
这是一个简单的 IBOutlet（直接来自 Apple 开发人员文档）。它给了我错误“'IBOutlet' 属性具有非可选类型'UIButton'”，我不知道如何修复它。
回答by idmean
It should be like that (in Beta 3 or before):
应该是这样的（在 Beta 3 或更早版本中）：
@IBOutlet var button: UIButton?
IBOutlets must be optionals so place a ?behind the type.
IBOutlets 必须是可选的，所以?在类型后面放置一个。
回答by Avi
It can also be-
也可以是——
@IBOutlet var button: UIButton!
or
或者
@IBOutlet var weak button: UIButton! (in case you are not doing view unloading)
if you are using XCODE 6 Beta 4
如果您使用的是 XCODE 6 Beta 4
回答by Varsha Vijayvargiya
class SecondViewController: UIViewController {
@IBOutlet weak var name: UILabel! = nil
override func viewDidLoad() {
super.viewDidLoad()
name.text="i m a label"
}
}
This code working fine
这段代码工作正常
But when i replace @IBOutlet weak var name: UILabel? it is not working.
但是当我替换@IBOutlet 弱变量名时：UILabel？它不工作。
