雨燕2.0的错误：警告：无法加载任何Objective-C类信息

Question

我得到这个错误：

warning: could not load any Objective-C class information

也

Thread 1: EXC_BAD_ACCESS(code=2,address=0x7fff5588dfb8)

...分配该类时：

import UIKit 
import QuartzCore 


class CERangeSliderKnobLayer: CALayer { 

    var highlighted = false 
    weak var slider = CERangeSlider() 

} 

对于像这样的变量：

import UIKit 

    class CERangeSlider: UIControl { 

     /* 
     // Only override drawRect: if you perform custom drawing. 
     // An empty implementation adversely affects performance during animation. 
     override func drawRect(rect: CGRect) { 
      // Drawing code 
     } 
     */ 
     var maximumValue = CGFloat() 
     var minimumValue = CGFloat() 
     var upperValue = CGFloat() 
     var lowerValue = CGFloat() 

     var trackLayer = CERangeSliderKnobLayer() 
     var upperKnobLayer = CERangeSliderKnobLayer() 
     var lowerKnobLayer = CERangeSliderKnobLayer() 

    ... 
    } 

这没有意义。我知道我的项目中绝对没有Objective C。这都是Swift。

UPDATE

如果你不初始化他们这样的，而不是把它们写像这样，即

var trackLayer: CERangeSliderKnobLayer! 

然后你会得到一个错误：

fatal error: unexpectedly found nil while unwrapping an Optional value

的东西如：

trackLayer.backgroundColor = UIColor.blueColor().CGColor 

Answer 1

由于某些原因，答案是改变我的班级，以便弱化财产未初始化：

import QuartzCore 


class CERangeSliderKnobLayer: CALayer { 

    var highlighted = false 
    weak var slider: CERangeSlider! 

}