我希望能够在我添加func之前运行一个在线教程中的一些示例代码。我想添加UIDynamics并将重力应用到图表/图形中一行上的一系列点，只是让它从屏幕上掉下来，但我似乎错过了一些东西？如果有人能告诉我为什么会喜欢它，那么[__ NSCFNumber center]无法识别的选择器被发送到实例会崩溃。
在线样本来自Ray Wenderlich的网站，由Caroline Begbie编写，用于教程。它很棒。然而，我添加的唯一功能就是崩溃了。
import UIKit
@IBDesignable class GraphView: UIView {
var graphPoints:[Int] = [4, 2, 6, 4, 5, 8, 3]
@IBInspectable var startColor: UIColor = UIColor.redColor()
@IBInspectable var endColor: UIColor = UIColor.greenColor()
override func drawRect(rect: CGRect) {
let width = rect.width
let height = rect.height
var path = UIBezierPath(roundedRect: rect,
byRoundingCorners: UIRectCorner.AllCorners,
cornerRadii: CGSize(width: 8.0, height: 8.0))
path.addClip()
let context = UIGraphicsGetCurrentContext()
let colors = [startColor.CGColor, endColor.CGColor]
let colorSpace = CGColorSpaceCreateDeviceRGB()
let colorLocations:[CGFloat] = [0.0, 1.0]
let gradient = CGGradientCreateWithColors(colorSpace,
colors,
colorLocations)
var startPoint = CGPoint.zeroPoint
var endPoint = CGPoint(x:0, y:self.bounds.height)
CGContextDrawLinearGradient(context,
gradient,
startPoint,
endPoint,
0)
let margin:CGFloat = 20.0
var columnXPoint = { (column:Int) -> CGFloat in
/
let spacer = (width - margin*2 - 4) /
CGFloat((self.graphPoints.count - 1))
var x:CGFloat = CGFloat(column) * spacer
x += margin + 2
return x
}
let topBorder:CGFloat = 60
let bottomBorder:CGFloat = 50
let graphHeight = height - topBorder - bottomBorder
let maxValue = maxElement(graphPoints)
var columnYPoint = { (graphPoint:Int) -> CGFloat in
var y:CGFloat = CGFloat(graphPoint) /
CGFloat(maxValue) * graphHeight
y = graphHeight + topBorder - y /
return y
}
UIColor.whiteColor().setFill()
UIColor.whiteColor().setStroke()
var graphPath = UIBezierPath()
graphPath.moveToPoint(CGPoint(x:columnXPoint(0),
y:columnYPoint(graphPoints[0])))
for i in 1..<graphPoints.count {
let nextPoint = CGPoint(x:columnXPoint(i),
y:columnYPoint(graphPoints[i]))
graphPath.addLineToPoint(nextPoint)
}
CGContextSaveGState(context)
var clippingPath = graphPath.copy() as! UIBezierPath
clippingPath.addLineToPoint(CGPoint(
x: columnXPoint(graphPoints.count - 1),
y:height))
clippingPath.addLineToPoint(CGPoint(
x:columnXPoint(0),
y:height))
clippingPath.closePath()
clippingPath.addClip()
let highestYPoint = columnYPoint(maxValue)
startPoint = CGPoint(x:margin, y: highestYPoint)
endPoint = CGPoint(x:margin, y:self.bounds.height)
CGContextDrawLinearGradient(context, gradient, startPoint, endPoint, 0)
CGContextRestoreGState(context)
graphPath.lineWidth = 2.0
graphPath.stroke()
for i in 0..<graphPoints.count {
var point = CGPoint(x:columnXPoint(i), y:columnYPoint(graphPoints[i]))
point.x -= 5.0/2
point.y -= 5.0/2
let circle = UIBezierPath(ovalInRect:
CGRect(origin: point,
size: CGSize(width: 5.0, height: 5.0)))
circle.fill()
}
var linePath = UIBezierPath()
linePath.moveToPoint(CGPoint(x:margin, y: topBorder))
linePath.addLineToPoint(CGPoint(x: width - margin,
y:topBorder))
linePath.moveToPoint(CGPoint(x:margin,
y: graphHeight/2 + topBorder))
linePath.addLineToPoint(CGPoint(x:width - margin,
y:graphHeight/2 + topBorder))
linePath.moveToPoint(CGPoint(x:margin,
y:height - bottomBorder))
linePath.addLineToPoint(CGPoint(x:width - margin,
y:height - bottomBorder))
let color = UIColor(white: 1.0, alpha: 0.3)
color.setStroke()
linePath.lineWidth = 1.0
linePath.stroke()
createFallAnimation() // my only func I added to the project
}
// My new code added to the project that is crashing it.
func createFallAnimation() {
var animator:UIDynamicAnimator? = nil
animator = UIDynamicAnimator(referenceView:self )
let gravity = UIGravityBehavior(items: graphPoints)
gravity.gravityDirection = CGVectorMake(0.0, 0.5)
animator?.addBehavior(gravity)
}
}
以下是崩溃日志：
2015-07-24 08:52:48.092 Flo[51164:11291157] -[__NSCFNumber center]: unrecognized selector sent to instance 0xb000000000000043
2015-07-24 08:52:48.097 Flo[51164:11291157] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFNumber center]: unrecognized selector sent to instance 0xb000000000000043'
*** First throw call stack:
(
0 CoreFoundation 0x000000010d55cc65 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x000000010f309bb7 objc_exception_throw + 45
2 CoreFoundation 0x000000010d5640ad -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
3 CoreFoundation 0x000000010d4ba13c ___forwarding___ + 988
4 CoreFoundation 0x000000010d4b9cd8 _CF_forwarding_prep_0 + 120
5 UIKit 0x000000010e7b7f11 -[UIDynamicAnimator _registerBodyForItem:shape:] + 672
6 UIKit 0x000000010e7bc006 -[UIGravityBehavior _addItem:] + 43
7 UIKit 0x000000010e7bc6b5 -[UIGravityBehavior _associate] + 293
8 UIKit 0x000000010e7b5b97 -[UIDynamicAnimator _registerBehavior:] + 244
9 Flo 0x000000010d3318db _TFC3Flo9GraphView20createAnimationStufffS0_FT_T_ + 331
10 Flo 0x000000010d33166b _TFC3Flo9GraphView8drawRectfS0_FVSC6CGRectT_ + 6555
11 Flo 0x000000010d33177d _TToFC3Flo9GraphView8drawRectfS0_FVSC6CGRectT_ + 93
12 UIKit 0x000000010e0bd5d2 -[UIView(CALayerDelegate) drawLayer:inContext:] + 495
13 QuartzCore 0x0000000112930a2a -[CALayer drawInContext:] + 119
14 QuartzCore 0x000000011282a92b CABackingStoreUpdate_ + 2793
15 QuartzCore 0x0000000112930933 ___ZN2CA5Layer8display_Ev_block_invoke + 59
16 QuartzCore 0x00000001129307be _ZN2CA5Layer8display_Ev + 1478
17 QuartzCore 0x00000001129254d9 _ZN2CA5Layer17display_if_neededEPNS_11TransactionE + 301
18 QuartzCore 0x0000000112925561 _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 35
19 QuartzCore 0x000000011289186e _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 242
20 QuartzCore 0x0000000112892a22 _ZN2CA11Transaction6commitEv + 462
21 UIKit 0x000000010e03b9ed -[UIApplication _reportMainSceneUpdateFinished:] + 44
22 UIKit 0x000000010e03c6b1 -[UIApplication _runWithMainScene:transitionContext:completion:] + 2648
23 UIKit 0x000000010e03b095 -[UIApplication workspaceDidEndTransaction:] + 179
24 FrontBoardServices 0x0000000111aed5e5 __31-[FBSSerialQueue performAsync:]_block_invoke_2 + 21
25 CoreFoundation 0x000000010d49041c __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
26 CoreFoundation 0x000000010d486165 __CFRunLoopDoBlocks + 341
27 CoreFoundation 0x000000010d485f25 __CFRunLoopRun + 2389
28 CoreFoundation 0x000000010d485366 CFRunLoopRunSpecific + 470
29 UIKit 0x000000010e03ab02 -[UIApplication _run] + 413
30 UIKit 0x000000010e03d8c0 UIApplicationMain + 1282
31 Flo 0x000000010d3432f7 main + 135
32 libdyld.dylib 0x000000010fa3f145 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
我有一种感觉我不能使用插入的数组元素？我认为他们需要成为对象？ 任何帮助都会很棒。如果您想自己搞乱整个项目，可以在Core Graphics和Swift第2部分的Ray Wenderlich上找到它。
答案 0 :(得分：0)
这是不正确的，目前还不清楚你想要发生什么：
var graphPoints:[Int] = [4, 2, 6, 4, 5, 8, 3]
...
let gravity = UIGravityBehavior(items: graphPoints)
这表示“请将重力行为附加到几个整数”。整数如何响应引力？
行为只能应用于符合UIDynamicItem的内容（包含bounds，center和transform的内容。整数没有任何这些，并且不清楚他们甚至可以如何。
您要做的事情（动画图表）要复杂得多。移动点时，您需要根据新点重绘路径。要设置动画，您需要使用可以为路径设置动画的内容（可能是CAShapeLayer，这样做很好）。这将是与此样本完全不同的代码。