UIViewControllerからUICollectionViewControllerへの遷移方法を教えてください！

Question

UIViewControllerからUICollectionViewControllerへの遷移方法を教えてください

MyFirstViewControllerからボタンを押してMySecondCollectionViewControllerに遷移方法を教えて欲しいです。

MyFirstViewController

import UIKit

class MyFirstViewController: UIViewController {
    let mybutton:UIButton = UIButton()
    override func viewDidLoad() {
        super.viewDidLoad()
        //ボタン
        let mybuttonrect:CGRect = CGRect(x:100, y: 100, width: 100, height: 100)
        mybutton.frame = mybuttonrect;
        mybutton.backgroundColor = UIColor.black
        mybutton.addTarget(self, action: #selector(mybuttonEvent(_:count:)), for: UIControl.Event.touchUpInside)
        self.view.addSubview(mybutton)
        // Do any additional setup after loading the view.
    }
    @objc func mybuttonEvent(_ sender: UIButton,count:Int) {
        let vc = MySecondCollectionViewController()
        vc.modalPresentationStyle = .fullScreen
        self.present(vc,animated: false,completion: nil)
    }
}

MySecondCollectionViewController

import UIKit
import TRMosaicLayout

private let reuseIdentifier = "cell"

class MySecondCollectionViewController: UICollectionViewController{
    let imagearray = ["image1", "image2", "image3", "image4", "image5", "image6","image7.png","image8.png"]

    override func viewDidLoad() {
        super.viewDidLoad()
        let mosaicLayout = TRMosaicLayout()
        self.collectionView?.collectionViewLayout = mosaicLayout
        mosaicLayout.delegate = self
        self.collectionView!.register(UICollectionViewCell.self, forCellWithReuseIdentifier: reuseIdentifier)
    }


    override func numberOfSections(in collectionView: UICollectionView) -> Int {
        return 1
    }

    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return imagearray.count
    }

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath)
        let imageView = UIImageView(image: UIImage(named: imagearray[indexPath.row]))
        imageView.frame = cell.frame
        cell.backgroundView = imageView
        // Configure the cell
        return cell
    }
}
extension MySecondCollectionViewController: TRMosaicLayoutDelegate {
    func collectionView(_ collectionView: UICollectionView, mosaicCellSizeTypeAtIndexPath indexPath: IndexPath) -> TRMosaicCellType {
        return indexPath.item % 3 == 0 ? TRMosaicCellType.big : TRMosaicCellType.small
    }

    func collectionView(_ collectionView:UICollectionView, layout collectionViewLayout: TRMosaicLayout, insetAtSection:Int) -> UIEdgeInsets {
    return UIEdgeInsets(top: 3, left: 3, bottom: 3, right: 3)
  }

  func heightForSmallMosaicCell() -> CGFloat {
    return 150
  }
}

エラー内容

で実行し、画面遷移するボタンを押したところエラーが発生しました。以下にエラー内容を示します。

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'UICollectionView must be initialized with a non-nil layout parameter'
*** First throw call stack:
(
	0   CoreFoundation                      0x00007fff23baa1ee __exceptionPreprocess + 350
	1   libobjc.A.dylib                     0x00007fff50864b20 objc_exception_throw + 48
	2   CoreFoundation                      0x00007fff23baa02c +[NSException raise:format:] + 188
	3   UIKitCore                           0x00007fff46d5793d -[UICollectionView initWithFrame:collectionViewLayout:] + 205
	4   UIKitCore                           0x00007fff46e49401 -[UICollectionViewController _newCollectionViewWithFrame:collectionViewLayout:] + 75
	5   UIKitCore                           0x00007fff46e48688 -[UICollectionViewController loadView] + 642
	6   UIKitCore                           0x00007fff46f0895f -[UIViewController loadViewIfRequired] + 172
	7   UIKitCore                           0x00007fff46f0910c -[UIViewController view] + 27
	8   UIKitCore                           0x00007fff46e22176 -[_UIFullscreenPresentationController _setPresentedViewController:] + 84
	9   UIKitCore                           0x00007fff46e152f7 -[UIPresentationController initWithPresentedViewController:presentingViewController:] + 184
	10  UIKitCore                           0x00007fff46f1a2fe -[UIViewController _presentViewController:withAnimationController:completion:] + 3553
	11  UIKitCore                           0x00007fff46f1cf97 __63-[UIViewController _presentViewController:animated:completion:]_block_invoke_2 + 70
	12  UIKitCore                           0x00007fff47a44c3e +[UIView(Animation) performWithoutAnimation:] + 84
	13  UIKitCore                           0x00007fff46f1ceec __63-[UIViewController _presentViewController:animated:completion:]_block_invoke + 211
	14  UIKitCore                           0x00007fff46f1d393 -[UIViewController _performCoordinatedPresentOrDismiss:animated:] + 511
	15  UIKitCore                           0x00007fff46f1cdd9 -[UIViewController _presentViewController:animated:completion:] + 187
	16  UIKitCore                           0x00007fff46f1d040 -[UIViewController presentViewController:animated:completion:] + 150
	17  ******                              0x0000000104d82188 $s6******21MyFirstViewControllerC13mybuttonEvent_5countySo8UIButtonC_SitF + 168
	18  ******                              0x0000000104d821ec $s6******21MyFirstViewControllerC13mybuttonEvent_5countySo8UIButtonC_SitFTo + 76
	19  UIKitCore                           0x00007fff4757a082 -[UIApplication sendAction:to:from:forEvent:] + 83
	20  UIKitCore                           0x00007fff46f608e5 -[UIControl sendAction:to:forEvent:] + 223
	21  UIKitCore                           0x00007fff46f60c2f -[UIControl _sendActionsForEvents:withEvent:] + 398
	22  UIKitCore                           0x00007fff46f5fb8e -[UIControl touchesEnded:withEvent:] + 481
	23  UIKitCore                           0x00007fff475b4a31 -[UIWindow _sendTouchesForEvent:] + 2604
	24  UIKitCore                           0x00007fff475b6338 -[UIWindow sendEvent:] + 4596
	25  UIKitCore                           0x00007fff47591693 -[UIApplication sendEvent:] + 356
	26  UIKitCore                           0x00007fff47611e5a __dispatchPreprocessedEventFromEventQueue + 6847
	27  UIKitCore                           0x00007fff47614920 __handleEventQueueInternal + 5980
	28  CoreFoundation                      0x00007fff23b0d271 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
	29  CoreFoundation                      0x00007fff23b0d19c __CFRunLoopDoSource0 + 76
	30  CoreFoundation                      0x00007fff23b0c974 __CFRunLoopDoSources0 + 180
	31  CoreFoundation                      0x00007fff23b0767f __CFRunLoopRun + 1263
	32  CoreFoundation                      0x00007fff23b06e66 CFRunLoopRunSpecific + 438
	33  GraphicsServices                    0x00007fff38346bb0 GSEventRunModal + 65
	34  UIKitCore                           0x00007fff47578dd0 UIApplicationMain + 1621
	35  ******                             0x0000000104d7fd9b main + 75
	36  libdyld.dylib                       0x00007fff516ecd29 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb) 

ご教示お願いします。

Comments

[thyda.eiqau]

「reason: 'UICollectionView must be initialized with a non-nil layout parameter'」と記載されていますが、こちらに対してどのようなアクションを取られましたか

[snakelegs]

エラー内容をネットで調べ、MyFirsViewtControllerの画面遷移のコードに
let layout = UICollectionViewFlowLayout()
layout.itemSize = CGSize(width:view.frame.width, height:view.frame.height)
vc.collectionView = UICollectionView(frame: CGRect.zero, collectionViewLayout: layout)
を追加して見ましたが、
'NSInternalInconsistencyException', reason: 'could not dequeue a view of kind: UICollectionElementKindCell with identifier cell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard'
とエラーが出ました。

[takabosoft]

SwiftUIタグは関係ないので外してください。

[snakelegs]

外しました。

Answer 1

遷移方法ではなくて、UICollectionViewControllerの使い方が判らないだけですよね？
また、Storyboardを使わないスタイルだと思いますが、であれば、

class MySecondCollectionViewController: UICollectionViewController{
    init() {
        let mosaicLayout = TRMosaicLayout()
        super.init(collectionViewLayout: mosaicLayout)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

などとイニシャライザでレイアウトを指定してみてはいかがでしょうか。

Comments

[snakelegs]

ありがとうございます！swiftをはじめたばかりで、UICollectionViewControllerの使い方の問題のようでしたすいません。実行して見たところエラーが出なくなりました。