在Swift中使用視覺格式語言和iCarousel

Question

我喜歡在我的swift項目中使用iCarousel，但有一件事我無法克服;我想在我的項目中使用Visual語言來佈局視圖，但是每當我使用iCarousel的可視化格式時，它都不起作用。

我注意到問題是TopMenuCarousel.translatesAutoresizingMaskIntoConstraints=false屬性。

每當我禁用此屬性，我的視覺格式約束被禁用的iCarousel，並且每當我啓用它，約束完美，但我的iCarousel將不會滾動並保持始終。

當前代碼：

＃

import UIKit 
import iCarousel 

class Step2_HomePage: UIViewController,iCarouselDelegate,iCarouselDataSource  { 


let TopMenuCarouselCount = 5 

    var TopMenuCarousel = iCarousel() 

override func viewDidLoad() { 
    super.viewDidLoad() 

    print("Step2HomePage icinde") 



    TopMenuCarousel = iCarousel(frame: CGRect()) 
    view.addSubview(TopMenuCarousel) 
    // TopMenuCarousel.clipsToBounds = true 
    TopMenuCarousel.type = .Linear 
    TopMenuCarousel.dataSource = self 
    TopMenuCarousel.delegate = self 






let views = [ "TopMenuCarousel": TopMenuCarousel ] 

    // 2 
    var allConstraints = [NSLayoutConstraint]() 



    let TopMenuCarouselTop = NSLayoutConstraint.constraintsWithVisualFormat(
     "V:|-100-[TopMenuCarousel]", 
     options: [], 
     metrics: nil, 
     views: views) 
    allConstraints += TopMenuCarouselTop 

    let TopMenuCarouselHorizontal = NSLayoutConstraint.constraintsWithVisualFormat(
     "H:|-0-[TopMenuCarousel]-0-|", 
     options: [], 
     metrics: nil, 
     views: views) 
    allConstraints += TopMenuCarouselHorizontal 



    TopMenuCarousel.translatesAutoresizingMaskIntoConstraints=false 
    NSLayoutConstraint.activateConstraints(allConstraints) 




    // Do any additional setup after loading the view, typically from a nib. 
} 

func numberOfItemsInCarousel(carousel: iCarousel) -> Int { 
    print("carousel number") 
    return TopMenuCarouselCount 

} 

func carousel(carousel: iCarousel, viewForItemAtIndex index: Int, reusingView view: UIView?) -> UIView { 
    print("carousel view icinde") 
    let tempView = UIView(frame: CGRect(x: 0, y: 0 , width: 20, height: 20)) 

    tempView.backgroundColor = UIColor.blueColor() 
    return tempView 
} 
override func didReceiveMemoryWarning() { 
    super.didReceiveMemoryWarning() 
    // Dispose of any resources that can be recreated. 
} 


} 

＃

Answer 1

你好像沒有什麼高度設置爲您iCarousel對象。嘗試將您的第一個約束更改爲：

let TopMenuCarouselTop = NSLayoutConstraint.constraintsWithVisualFormat(
    "V:|-100-[TopMenuCarousel(20)]", 
    options: [], 
    metrics: nil, 
    views: views) 

這是您的原始代碼的完整修改版本。我提出了更大的意見（你的是20x20），並添加了一些顏色，以便更容易看到發生了什麼。

import UIKit 
import iCarousel 

class Step2_HomePage: UIViewController,iCarouselDelegate,iCarouselDataSource { 

    // array of colors to make it easy to see the individual Carousel views 
    let arrayOfColors = [ UIColor.blueColor(), UIColor.redColor(), UIColor.yellowColor(), UIColor.orangeColor(), UIColor.greenColor()] 

    let TopMenuCarouselCount = 5 

    var TopMenuCarousel = iCarousel() 

    override func viewDidLoad() { 
     super.viewDidLoad() 

     print("Step2HomePage icinde") 

     self.view.backgroundColor = UIColor.lightGrayColor() 

     // initialize the TopMenuCarousel object 
     TopMenuCarousel = iCarousel(frame: CGRect()) 

     // add TopMenuCarousel to the view 
     view.addSubview(TopMenuCarousel) 

     // if clipsToBounds == true, TopMenuCarousel subviews will be clipped to the TopMenuCarousel frame 
     // default is false 

     //  TopMenuCarousel.clipsToBounds = true 

     TopMenuCarousel.type = .Linear 
     TopMenuCarousel.dataSource = self 
     TopMenuCarousel.delegate = self 

     TopMenuCarousel.backgroundColor = UIColor.purpleColor() 

     let views = [ "TopMenuCarousel": TopMenuCarousel ] 

     var allConstraints = [NSLayoutConstraint]() 

     // position TopMenuCarousel 100 from the Top, with a Height of 200 
     let TopMenuCarouselTop = NSLayoutConstraint.constraintsWithVisualFormat(
      "V:|-100-[TopMenuCarousel(200)]", 
      options: [], 
      metrics: nil, 
      views: views) 

     allConstraints += TopMenuCarouselTop 

     // set TopMenuCarousel to stretch the full Width of the view 
     let TopMenuCarouselHorizontal = NSLayoutConstraint.constraintsWithVisualFormat(
      "H:|-0-[TopMenuCarousel]-0-|", 
      options: [], 
      metrics: nil, 
      views: views) 

     allConstraints += TopMenuCarouselHorizontal 

     // this property *must* be set to false 
     TopMenuCarousel.translatesAutoresizingMaskIntoConstraints=false 

     NSLayoutConstraint.activateConstraints(allConstraints) 

    } 

    func numberOfItemsInCarousel(carousel: iCarousel) -> Int { 
     print("carousel number \(TopMenuCarouselCount)") 
     return TopMenuCarouselCount 
    } 

    func carousel(carousel: iCarousel, viewForItemAtIndex index: Int, reusingView view: UIView?) -> UIView { 
     print("carousel view icinde", index) 

     // create a 200 x 160 view to add to TopMenuCarousel 
     let tempView = UIView(frame: CGRect(x: 0, y: 0 , width: 200, height: 160)) 

     // give it one of the colors 
     tempView.backgroundColor = arrayOfColors[index % arrayOfColors.count] 

     return tempView 
    } 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
     // Dispose of any resources that can be recreated. 
    } 


} 

Answer 2

約束被創建和激活，但從未添加到視圖，您應該使用：

view.addConstraints(allConstraints) 

後

NSLayoutConstraint.activateConstraints(allConstraints) 

另外，作爲DonMag說，沒有高度的限制，這意味着如果iCarousel視圖沒有正確的固有尺寸，它將不會顯示，您應該添加一個像DonMag寫的示例一樣的明確高度。