如何检测touchbegan和触摸移动ios SWIFT中的angular度？

我应该如何使用ios swift检测touchbegan和touchmoved事件的angular度。

我想检测在ios快速uiview上完成的动作的angular度

Answer 1

这取决于你的angular度的angular度，但不健康的假设水平为零

步骤是

• 陷阱开始点
• 捕捉终点触摸移动
• 使用基本三angular法计算angular度。 请注意，所有的标准CmathAPI都可以在Swift中使用。

一个基本的实现可能是

import UIKit class AngleOfDangle:UIView { var touchDown:CGPoint = CGPointZero var endPoint:CGPoint = CGPointZero var gotLock:Bool = false override func touchesBegan(touches: NSSet, withEvent event: UIEvent) { //we want only one pointy thing if touches.count == 1 { gotLock = true if let touch = touches.anyObject() as? UITouch { touchDown = touch.locationInView(self) } } } override func touchesMoved(touches: NSSet, withEvent event: UIEvent) { if touches.count == 1 { if let touch = touches.anyObject() as? UITouch { endPoint = touch.locationInView(self) let angle = self.angle(touchDown, end: endPoint) println("the angle is \(angle)") } } else { gotLock = false } self.setNeedsDisplay() } func angle(start:CGPoint,end:CGPoint)->Double { let dx = end.x - start.x let dy = end.y - start.y let abs_dy = fabs(dy); //calculate radians let theta = atan(abs_dy/dx) let mmmm_pie:CGFloat = 3.1415927 //calculate to degrees , some API use degrees , some use radians let degrees = (theta * 360/(2*mmmm_pie)) + (dx < 0 ? 180:0) //transmogrify to negative for upside down angles let negafied = dy > 0 ? degrees * -1:degrees return Double(negafied) } override func drawRect(rect: CGRect) { if gotLock { var level = UIBezierPath() level.moveToPoint(CGPointMake(0, touchDown.y)) level.addLineToPoint(CGPointMake(CGRectGetWidth(self.frame), touchDown.y)) level.stroke() var path = UIBezierPath() path.moveToPoint(touchDown) path.addLineToPoint(endPoint) path.stroke() } } }