使用UIPanGestureRecognizer将视图从一个位置拖动到有限位置

let panGesture = UIPanGestureRecognizer(target: self, action: #selector(handlePan(_:)))
view.addGestureRecognizer(panGesture)

@objc func handlePan(_ gesture: UIPanGestureRecognizer) {
    let translation = gesture.translation(in: view)
    guard let draggedView = gesture.view else { return }
    
    // 计算拖动后的视图位置
    let newX = draggedView.center.x + translation.x
    let newY = draggedView.center.y + translation.y
    
    // 限制视图的位置范围
    let minX: CGFloat = 0
    let minY: CGFloat = 0
    let maxX: CGFloat = view.bounds.width - draggedView.bounds.width
    let maxY: CGFloat = view.bounds.height - draggedView.bounds.height
    
    let clampedX = min(maxX, max(minX, newX))
    let clampedY = min(maxY, max(minY, newY))
    
    // 更新视图的位置
    draggedView.center = CGPoint(x: clampedX, y: clampedY)
    
    // 重置手势的位移
    gesture.setTranslation(.zero, in: view)
}