如何使用一根手指而不是两根手指移动贴图(在WKWebView中)

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

@objc func handlePanGesture(_ gesture: UIPanGestureRecognizer) {
    let translation = gesture.translation(in: webView)
    let point = gesture.location(in: webView)
    
    switch gesture.state {
    case .began:
        // 在手势开始时，判断触摸点是否在贴图上
        if isPointOnSticker(point) {
            // 如果是，则记录下贴图的初始位置
            stickerInitialPosition = stickerView.frame.origin
        }
    case .changed:
        // 在手势移动时，更新贴图的位置
        if let initialPosition = stickerInitialPosition {
            let newPosition = CGPoint(x: initialPosition.x + translation.x, y: initialPosition.y + translation.y)
            stickerView.frame.origin = newPosition
        }
    case .ended, .cancelled:
        // 手势结束时，清空贴图的初始位置
        stickerInitialPosition = nil
    default:
        break
    }
}

func isPointOnSticker(_ point: CGPoint) -> Bool {
    // 判断逻辑，例如判断点是否在贴图的frame内部
    return stickerView.frame.contains(point)
}