每次向右滑动我都想添加一个新的 subview ,但是如果我不破坏之前的 subview ,它会堆叠很多次。我知道如何删除它,但我正在为如何在添加新的之后才删除它的逻辑而苦苦挣扎。
我试过这个:
var view1: UIView?
var view2: UIView?
var ctrl = false
override func viewDidLoad() {
super.viewDidLoad()
view1?.addSubview(CustomView(frame: self.view.bounds))
}
func addView(){
if let test1 = view1, let test2 = view2 {
if ctrl == true {
test1.addSubview(CustomView(frame: self.view.bounds))
test2.removeFromSuperview()
ctrl = false
}else{
test2.addSubview(CustomView(frame: self.view.bounds))
test1.removeFromSuperview()
ctrl = true
}
}
}
@IBAction func swipeRight(_ sender: Any) {
print("Right")
UIView.animate(withDuration: 1, animations: {
self.view.layer.backgroundColor = .black
}){(isFinished) in
self.addView()
//I am hoping that after this the view stack before will be removed
}
}
类 CustomView 是这样的:
var primaryColors: [UIColor] = [
.red,
.yellow,
.blue]
class CustomView: UIView {
override func draw(_ rect: CGRect) {
super.draw(rect)
primaryColors.shuffle()
let leftRect = CGRect(x: 0, y: 0, width: rect.size.width/2, height: rect.size.height)
primaryColors[0].set()
guard let leftContext = UIGraphicsGetCurrentContext() else { return }
leftContext.fill(leftRect)
let rightRect = CGRect(x: rect.size.width/2, y: 0, width: rect.size.width/2, height: rect.size.height)
primaryColors[1].set()
guard let rightContext = UIGraphicsGetCurrentContext() else { return }
rightContext.fill(rightRect)
}
}
最佳答案
嗯,我不太擅长 swift,但在我理解你的问题之前,这应该可以解决它。 如果没有,我敢肯定会有更好的 swift 人以更好的方式回答它。
每个 ViewController
都有一个基本的 view
,您可以像 view.method()
一样访问它。
您将 subview 添加到现有 View 。
假设您要添加一个名为 view1 的新 UIView。
首先你初始化它,
view1 = UIView(frame: view.bounds)
现在让它出现在屏幕上,点赞
view.addSubview(view1)
此行会将 view1
添加为 view
的 subview 。
此外,现在 view1
位于 view
之上。所以现在当你触摸你的屏幕时,它就是你正在访问的 view1
。
所以下次你向右滑动时,手势识别器应该在 view1
上。
let swipeRight = UISwipeGestureRecognizer(target: self, action: #selector(swipeRightAction))
swipeRight.direction = UISwipeGestureRecognizer.Direction.right
view1.addGestureRecognizer(swipeRight)
这就是将向右滑动手势添加到 view1 的方式。
现在,当您在屏幕上向右滑动时,swipeRightAction()
将被调用。
您可以从 super View 中删除此 view1
,例如,
view1.removeFromSuperView()
现在 view1 不见了,现在您可以通过与添加 view1
类似的过程添加 view2
。
请看下面的代码,它可能是相关的。
//The old view that has to be replaced
var viewToBeRemoved : UIView!
//The new view that will replace the previous one
var viewToBeAdded : UIView!
override func viewDidLoad() {
super.viewDidLoad()
replaceWithNewSwipableSubview()
}
func replaceWithNewSwipableSubview()
{
viewToBeAdded = UIView(frame: view.bounds)
//New view being added should have a gesture so that next time
//it need to be replaced we can swipe on it
let swipeRight = UISwipeGestureRecognizer(target: self, action: #selector(swipeRightAction))
swipeRight.direction = UISwipeGestureRecognizer.Direction.right
viewToBeAdded.addGestureRecognizer(swipeRight)
UIView.animate(withDuration: 1, animations: {
//This will be animated
if self.viewToBeRemoved != nil{
//As there is no subview the very first time this func is called
self.viewToBeRemoved.removeFromSuperview()
}
//Because next time it will be the view to be removed
self.viewToBeRemoved = self.viewToBeAdded
}) { (isFinished) in
//This block gets executed only after
//the block above has completed
self.view.addSubview(self.viewToBeAdded)
//view is the default base view of a ViewController
}
}
@objc func swipeRightAction() {
replaceWithNewSwipableSubview()
}
在您的代码 view1?.addSubview(CustomView(frame: self.view.bounds))
中,此行向 view1 添加了一个 View ,您没有引用要添加的 View 。您应该首先存储您添加的 View ,如 view3 = CustomView(frame: self.view.bounds)
以便稍后您可以删除 view3。此外,您的 view1
实际上永远不会被添加 如果我是对的,因为要添加 view1
您需要先添加 view.addSubview(view1)
。
尽管如果您告诉我们您实际想要实现的目标,可能会建议更好的解决方案?
关于swift - 添加新的 UIView 后如何删除以前的堆栈?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/56310964/