博客

直接看代码

   private let btnWH = 75.0 //按钮宽高
    lazy var btn:UIButton = {
        let btn = UIButton(frame: CGRect(x: kScreenWidth - 100, y: 300, width: btnWH, height: btnWH))
        btn.setImage(UIImage(named: "testimage"), for: .normal)
        btn.addTarget(self, action: #selector(clickSuspendBtnAction), for: .touchUpInside)
        let pantouch = UIPanGestureRecognizer.init(target: self, action: #selector(handlePan))
        btn.addGestureRecognizer(pantouch)
       return btn
    }()
    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .brown
        view.addSubview(btn)
    }

 @objc func handlePan(recognizer : UIPanGestureRecognizer) {
        guard let rView = recognizer.view else {
            return
        }
        let translation = recognizer.translation(in: self.view)
        let centerX = rView.center.x + translation.x
        var theCenter:CGFloat = 0
        rView.center = CGPoint(x: centerX, y: rView.center.y + translation.y)
        recognizer.setTranslation(CGPoint.zero, in: self.view)
        if recognizer.state == .ended || recognizer.state == .cancelled {
            if centerX > (kScreenWidth / 2) {
                theCenter = kScreenWidth - btnWH / 2
            } else {
                theCenter = btnWH / 2
            }
            
            var contentOff_Y = rView.center.y
            if contentOff_Y > kScreenHeight - kNavBarHeight(self) - 40 {
                contentOff_Y = kScreenHeight - kNavBarHeight(self) - 37.5
            }
            
            if contentOff_Y < kNavBarHeight(self) + kTabBarHeight(self) {
                contentOff_Y = kNavBarHeight(self) + kTabBarHeight(self) + 37.5
            }
            UIView.animate(withDuration: 0.3) {
                rView.center = CGPoint(x: theCenter, y: contentOff_Y + translation.y)
            }
        }
    }
    @objc func clickSuspendBtnAction(){
        
    }