[英]snapchat-like pinch zoom on iOS
我已经在 swift 中发布了 iOS 应用程序,其主要功能是:1) 添加照片/拍照 2) 在照片上添加表情符号 3) 缩放、旋转、拖动表情符号来装饰照片 4) 在 Instagram 上分享。
表情符号可以旋转、缩放和拖动。 我已经使用 UIGestureRecognizers 实现了这些功能,例如 UIRoationGestrueRecognizer、UIPinchGestureRecognizer 和 UIPanGesstureRecognizer。
现在我正在尝试使用类似 snapchat 的捏缩放功能来更新应用程序,用户可以在其中将两个手指之间的表情符号放大/缩小到极致。 当前的捏合手势仅在用户的手指位于 imageView(表情符号)上时才有效。
任何想法/示例代码如何进行类似 snapchat 的捏合缩放? 下面的代码是我处理旋转、捏合和拖动的方式。 提前致谢。
// UI Gesture Recognizers
@IBAction func handlePinch(recognizer : UIPinchGestureRecognizer) {
if(deleteMode) {
return
}
if let view = recognizer.view {
view.transform = CGAffineTransformScale(view.transform,
recognizer.scale, recognizer.scale)
recognizer.scale = 1
}
}
@IBAction func handleRotate(recognizer : UIRotationGestureRecognizer) {
if(deleteMode) {
return
}
if let view = recognizer.view {
view.transform = CGAffineTransformRotate(view.transform, recognizer.rotation)
recognizer.rotation = 0
}
}
@IBAction func handlePan(recognizer:UIPanGestureRecognizer) {
if(deleteMode) {
return
}
let translation = recognizer.translationInView(self.view)
var centerX: CGFloat!
var centerY: CGFloat!
if let view = recognizer.view {
// limit the boundary - using backgroundPanel.frame.width, height, origin.x, origin.y
if(view.center.x + translation.x < panelBackground.frame.origin.x) {
centerX = view.center.x + translation.x + 10
} else if(view.center.x > panelBackground.frame.size.width){
centerX = view.center.x + translation.x - 10
} else {
centerX = view.center.x + translation.x
}
if(view.center.y < panelBackground.frame.origin.y - 60){
// set y that I can use below
centerY = view.center.y + translation.y + 10
} else if(view.center.y > panelBackground.frame.size.height){
centerY = view.center.y + translation.y - 10
} else {
centerY = view.center.y + translation.y
}
// set final position
view.center = CGPoint(x:centerX,
y:centerY)
recognizer.setTranslation(CGPointZero, inView: self.view)
}
}
@IBAction func handleLongPress(recognizer: UILongPressGestureRecognizer) {
if(recognizer.state == UIGestureRecognizerState.Began) {
if(!deleteMode) {
print("LongPress - Delete Shows")
for (_, stickers) in self.backgroundImage.subviews.enumerate() {
for (_, deleteButtons) in stickers.subviews.enumerate() {
if let delete:UIImageView = deleteButtons as? UIImageView{
if(delete.accessibilityIdentifier == "delete") {
delete.alpha = 0.5
}
}
}
}
deleteMode = true
} else {
deleteButtonHides()
}
}
}
我也在寻找像 snapchat 一样同时进行拖动、平移和缩放,但如果您只是在寻找缩放功能。 我正在使用以下函数作为标签以通过捏合进行缩放。 它不平滑,但可以完成缩放工作。
func handlePinch(recognizer: UIPinchGestureRecognizer) {
if let view = recognizer.view as? UILabel {
let pinchScale: CGFloat = recognizer.scale
view.transform = view.transform.scaledBy(x: pinchScale, y: pinchScale)
recognizer.scale = 1.0
}
}
要同时拖动、平移和缩放,请查看我的以下帖子:
要实现像捏缩放这样的 Snapchat,还可以在父视图上添加捏合手势,而不是识别器转换所选的贴纸,如下所示:
@objc func mainImgPinchGesture(_ recognizer: UIPinchGestureRecognizer) {
print("----pinchGestureAction")
if let view = recognizer.view {
if selectedSubView != nil{
self.selectedSubView.transform = view.transform.scaledBy(x: recognizer.scale, y: recognizer.scale)
self.selectedSubView.contentScaleFactor = 1
}
}
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.