我已经看到了几个关于向子视图添加GestureRecognzier
的答案,但我的问题是我没有预先提供subView的框架。我正在绘制CGPath
,并且在Touches Ended
方法中,我想创建一个新的subView
,其框架等于CGPath
边界框。之后,我想将subView
与PanGestureRecognizer
拖动。我正在尝试实现Evernote crop
功能,用户选择某个视图区域并将其移动到其他位置。这是解决方案的正确方法吗?
答案 0 :(得分:0)
不太了解UIGestureRecognizer
和.frame
之间的关系。一旦init工作完成,你就可以简单地将UIGestureRecognizer
添加到object。
在绘制子视图后,尝试直接在TouchEnd
方法中添加手势。
import UIKit
class GestureResearchVC: UIViewController{
var subViewByCGPath: UIView?
override func viewDidLoad() {
super.viewDidLoad()
}
func createSubView(){
//creat subview
subViewByCGPath = UIView(frame: CGRect(x: 100, y: 100, width: 100, height: 100))
subViewByCGPath?.backgroundColor = UIColor.yellow
let circlePath = UIBezierPath(arcCenter: CGPoint(x: 50,y: 50), radius: CGFloat(20), startAngle: CGFloat(0), endAngle:CGFloat(M_PI * 2), clockwise: true)
let shapeLayer = CAShapeLayer()
shapeLayer.path = circlePath.cgPath
shapeLayer.strokeColor = UIColor.red.cgColor
subViewByCGPath?.layer.addSublayer(shapeLayer)
self.view.addSubview(subViewByCGPath!)
//add pan gesture to subViewByCGPath
let gesture = UIPanGestureRecognizer(target: self, action: #selector(panGestureAction(rec:)))
subViewByCGPath?.addGestureRecognizer(gesture)
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
if subViewByCGPath == nil {
print("touch end once")
createSubView()
}else{
print("touch end repeatedly")
}
}
func panGestureAction(rec: UIPanGestureRecognizer){
print("pannnnnnn~")
let transPoint = rec.translation(in: self.view)
let x = rec.view!.center.x + transPoint.x
let y = rec.view!.center.y + transPoint.y
rec.view!.center = CGPoint(x: x, y: y)
rec.setTranslation(CGPoint(x: 0, y: 0), in: self.view)
//distinguish state
switch rec.state {
case .began:
print("began")
case .changed:
print("changed")
case .ended:
print("ended")
default:
print("???")
}
}
}