我正在使用约束来设置两个视图之间的边界。平移手势用于跟踪用户手指在拖动边界时的垂直移动。
当拖动时间过长时，应用程序崩溃，几乎没有任何解释。下面是崩溃的输出（其他崩溃产生了更短的输出），我不明白。我认为相关的代码低于它。
非常感谢您帮助理解和纠正此问题。谢谢。
libobjc.A.dylib`objc_msgSend:
0x180d95bc0 <+0>: cmp x0, #0
0x180d95bc4 <+4>: b.le 0x180d95c2c ; <+108>
-> 0x180d95bc8 <+8>: ldr x13, [x0]
0x180d95bcc <+12>: and x9, x13, #0x1fffffff8
0x180d95bd0 <+16>: ldp x10, x11, [x9, #16]
0x180d95bd4 <+20>: and w12, w1, w11
0x180d95bd8 <+24>: add x12, x10, x12, lsl #4
0x180d95bdc <+28>: ldp x16, x17, [x12]
0x180d95be0 <+32>: cmp x16, x1
0x180d95be4 <+36>: b.ne 0x180d95bec ; <+44>
0x180d95be8 <+40>: br x17
0x180d95bec <+44>: cbz x16, 0x180d95d80 ; _objc_msgSend_uncached_impcache
0x180d95bf0 <+48>: cmp x12, x10
0x180d95bf4 <+52>: b.eq 0x180d95c00 ; <+64>
0x180d95bf8 <+56>: ldp x16, x17, [x12, #-16]!
0x180d95bfc <+60>: b 0x180d95be0 ; <+32>
0x180d95c00 <+64>: add x12, x12, w11, uxtw #4
0x180d95c04 <+68>: ldp x16, x17, [x12]
0x180d95c08 <+72>: cmp x16, x1
0x180d95c0c <+76>: b.ne 0x180d95c14 ; <+84>
0x180d95c10 <+80>: br x17
0x180d95c14 <+84>: cbz x16, 0x180d95d80 ; _objc_msgSend_uncached_impcache
0x180d95c18 <+88>: cmp x12, x10
0x180d95c1c <+92>: b.eq 0x180d95c28 ; <+104>
0x180d95c20 <+96>: ldp x16, x17, [x12, #-16]!
0x180d95c24 <+100>: b 0x180d95c08 ; <+72>
0x180d95c28 <+104>: b 0x180d95d80 ; _objc_msgSend_uncached_impcache
0x180d95c2c <+108>: b.eq 0x180d95c44 ; <+132>
0x180d95c30 <+112>: adrp x10, 123003
0x180d95c34 <+116>: add x10, x10, #816
0x180d95c38 <+120>: lsr x11, x0, #60
0x180d95c3c <+124>: ldr x9, [x10, x11, lsl #3]
0x180d95c40 <+128>: b 0x180d95bd0 ; <+16>
0x180d95c44 <+132>: movz x1, #0
0x180d95c48 <+136>: movi d0, #0000000000000000
0x180d95c4c <+140>: movi d1, #0000000000000000
0x180d95c50 <+144>: movi d2, #0000000000000000
0x180d95c54 <+148>: movi d3, #0000000000000000
0x180d95c58 <+152>: ret
0x180d95c5c <+156>: nop
以下是平移手势识别器调用的代码：
@IBAction func pan(gesture: UIPanGestureRecognizer) {
switch gesture.state {
case .Ended:
captureViewSplit()
saveSermonSettingsBackground()
break
case .Changed:
let translation = gesture.translationInView(splitView)
let change = -translation.y
if change != 0 {
gesture.setTranslation(CGPointZero, inView: splitView)
setSermonNotesAndSlidesConstraint(change)
self.view.setNeedsLayout()
self.view.layoutSubviews()
}
break
default:
break
}
}
以下是约束更新的代码：
private func setSermonNotesAndSlidesConstraint(change:CGFloat)
{
let newConstraintConstant = self.sermonNotesAndSlidesConstraint.constant + change
let (minConstraintConstant,maxConstraintConstant) = sermonNotesAndSlidesConstraintMinMax(self.view.bounds.height)
if (newConstraintConstant >= minConstraintConstant) && (newConstraintConstant <= maxConstraintConstant) {
self.sermonNotesAndSlidesConstraint.constant = newConstraintConstant
} else {
if newConstraintConstant < minConstraintConstant { self.sermonNotesAndSlidesConstraint.constant = minConstraintConstant }
if newConstraintConstant > maxConstraintConstant { self.sermonNotesAndSlidesConstraint.constant = maxConstraintConstant }
}
splitView.min = minConstraintConstant
splitView.max = maxConstraintConstant
splitView.height = self.sermonNotesAndSlidesConstraint.constant
self.view.setNeedsLayout()
}
private func sermonNotesAndSlidesConstraintMinMax(height:CGFloat) -> (min:CGFloat,max:CGFloat)
{
let minConstraintConstant:CGFloat = tableView.rowHeight*1 + slider.bounds.height + 16 //margin on top and bottom of slider
let maxConstraintConstant:CGFloat = height - logo.bounds.height - slider.bounds.height - navigationController!.navigationBar.bounds.height
return (minConstraintConstant,maxConstraintConstant)
}
下面是绘制描绘两个视图之间分割的图形的自定义类的代码。
@IBDesignable
class SplitView: UIView {
var splitViewController:UISplitViewController?
var lineWidth: CGFloat = 1.0 { didSet { setNeedsDisplay() } }
var color: UIColor = UIColor.blackColor() { didSet { setNeedsDisplay() } }
var scale: CGFloat = 1.0 { didSet { setNeedsDisplay() } }
var height:CGFloat = 200 {
didSet {
setNeedsDisplay()
}
}
var min:CGFloat = 50 {
didSet {
setNeedsDisplay()
}
}
var max:CGFloat = 500 {
didSet {
setNeedsDisplay()
}
}
private var splitCenter: CGPoint? {
var splitPoint:CGPoint?
splitPoint = CGPointMake(self.bounds.width / 2, self.bounds.height - height)
return splitPoint
}
override func drawRect(rect: CGRect)
{
if let startingPoint = splitCenter {
let context = UIGraphicsGetCurrentContext()
CGContextSaveGState(context)
let indicatorPath = UIBezierPath()
let height:CGFloat = bounds.width/4
let left = CGPoint(x: startingPoint.x - bounds.width/2, y: startingPoint.y)
indicatorPath.moveToPoint(left)
let right = CGPoint(x: startingPoint.x + bounds.width/2, y: startingPoint.y)
indicatorPath.addLineToPoint(right)
// print("startingPoint.y: \(round(startingPoint.y)) min: \(round(min)) max: \(round(max))")
if (round(startingPoint.y) > (bounds.height - round(max))) {
let bottom = CGPoint(x: startingPoint.x, y: startingPoint.y - height)
indicatorPath.moveToPoint(bottom)
indicatorPath.addLineToPoint(left)
indicatorPath.moveToPoint(bottom)
indicatorPath.addLineToPoint(right)
}
if (round(startingPoint.y) < (bounds.height - round(min))) {
let top = CGPoint(x: startingPoint.x, y: startingPoint.y + height)
indicatorPath.moveToPoint(top)
indicatorPath.addLineToPoint(left)
indicatorPath.moveToPoint(top)
indicatorPath.addLineToPoint(right)
}
indicatorPath.lineWidth = lineWidth
color.set()
indicatorPath.stroke()
let boundsPath = UIBezierPath()
boundsPath.moveToPoint(bounds.origin)
boundsPath.addLineToPoint(CGPoint(x: bounds.origin.x + bounds.width, y: bounds.origin.y))
if (splitViewController == nil) {
boundsPath.addLineToPoint(CGPoint(x: bounds.origin.x + bounds.width, y: splitCenter!.y))
boundsPath.addLineToPoint(CGPoint(x: bounds.origin.x, y: splitCenter!.y))
} else {
boundsPath.addLineToPoint(CGPoint(x: bounds.origin.x + bounds.width, y: bounds.origin.y + bounds.height))
boundsPath.addLineToPoint(CGPoint(x: bounds.origin.x, y: bounds.origin.y + bounds.height))
}
boundsPath.addLineToPoint(bounds.origin)
boundsPath.lineWidth = lineWidth / 2
color.set()
boundsPath.stroke()
CGContextRestoreGState(context)
} else {
print("No starting point!")
}
}
}
答案 0 :(得分：0)
问题是我正在设置WKWebView的scrollView委托，根据经验，我发现必须在viewWillDisappear（）上设置为nil，否则应用程序会崩溃。通过将代理设置为nil on .Began在平移手势识别器中并返回自我.Ended问题消失了。