如何刪除視圖並更新約束？

Question

我有一個視圖，我在編程上通過xib添加按鈕來創建另一個視圖。我能夠創建多個視圖點擊添加更多按鈕和刪除也工作，如果我刪除最後一個視圖，但問題發生在中間視圖由於缺少約束查看不正確更新波紋管圖像它是如何看待

在開始查看這個樣子

添加更多視圖後

除去中間視圖後

刪除按鈕代碼

@IBAction func deletebnt(_ sender: UIButton) { 
     let view = self.superview 
     let index = view?.subviews.index(of:self)! 
     delegate.txtcheck(text: countstr) 
     self.view.removeFromSuperview() 
    } 

添加按鈕代碼

@IBAction func addMoreBnt(_ sender: UIButton) { 
     for constraint in addSuperview.constraints { 
      if constraint.firstAttribute == NSLayoutAttribute.height 
      { 
       constraint.constant += 45 
       space = constraint.constant 
      } 
     } 
     let newView : AvalabileTimeView = AvalabileTimeView() 
     newView.frame = CGRect(x: self.addsubView.frame.origin.x, y: 70, width: addsubView.frame.size.width, height:addsubView.frame.size.height) 
     newView.delegate = self as AvalabileTimeDelegate 
     addSuperview.addSubview(newView) 
     let index = addSuperview.subviews.index(of: newView)!   
     newView.translatesAutoresizingMaskIntoConstraints = false 
     let heightConstraint = newView.widthAnchor.constraint(equalToConstant:addsubView.frame.size.width) 
     let widthConstaint = newView.heightAnchor.constraint(equalToConstant:31) 
     let topConstraint = newView.topAnchor.constraint(equalTo: addSuperview.topAnchor, constant: space - 31) NSLayoutConstraint.activate([heightConstraint,topConstraint,widthConstaint]) 

    } 

委託來改變上海華

的高度0

func txtcheck(text: String!) { 
     print(text) 
     for constraint in addSuperview.constraints { 
      if constraint.firstAttribute == NSLayoutAttribute.height 
      { 
       constraint.constant -= 45 
       // Here I have to set constraint for bottom view and topview of deleted view but I don't know how to do 
      } 
     } 
    } 

這裏是鏈接到演示項目 https://github.com/logictrix/addFieldDemo

Answer 1

而是有自己的約束添加每個新AvalabileTimeView的，使用UIStackView - 你可以刪除幾乎所有的現有代碼的添加/刪除新的看法。

看.addArrangedSubview()和.removeArrangedSubview()

下面是一些示例代碼...你需要在Interface Builder添加UIStackView，它連接到電源插座，並調整限制，但是這就是全部：

// in ViewController.swift 

@IBOutlet weak var availableTimeStackView: UIStackView! 

@IBAction func addMoreBnt(_ sender: UIButton) { 

    // instantiate a new AvalabileTimeView 
    let newView : AvalabileTimeView = AvalabileTimeView() 

    // set its delegate to self 
    newView.delegate = self as AvalabileTimeDelegate 

    // add it to the Stack View 
    availableTimeStackView.addArrangedSubview(newView) 

    // standard for auto-layout 
    newView.translatesAutoresizingMaskIntoConstraints = false 

    // only constraint needed is Height (width and vertical spacing handled by the Stack View) 
    newView.heightAnchor.constraint(equalToConstant: 31).isActive = true 

} 

// new delegate func 
func removeMe(_ view: AvalabileTimeView) { 

    // remove the AvalabileTimeView from the Stack View 
    availableTimeStackView.removeArrangedSubview(view) 

} 

---

// in AvalabileTimeView.swift 

protocol AvalabileTimeDelegate{ 
    // don't need this anymore 
    func txtcheck(text: String!) 

    // new delegate func 
    func removeMe(_ view: AvalabileTimeView) 
} 

@IBAction func deletebnt(_ sender: UIButton) { 
    delegate.removeMe(self) 
}