我正在更改我的应用程序，以开始在主页上使用工具栏按钮而不是菜单。所有菜单链接均有效，而除一页外，工具栏按钮均适用于所有页面。当我单击按钮时，应用程序冻结，Xcode将我带到这一行： '弱var itemDetailPage = segue.destination为？ ItemDetailViewController”，出现此错误： 线程1：EXC_BAD_INSTRUCTION（代码= EXC_I386_INVOP，子代码= 0x0） 所有变量均为零。
任何帮助都是巨大的！
这是专门针对以下视图控制器的代码：
import UIKit
import AVFoundation
import Alamofire
@objc protocol FavRefreshLikeCountsDelegate: class {
func updateLikeCounts(_ likeCount: Int)
}
@objc protocol FavRefreshReviewCountsDelegate: class {
func updateReviewCounts(_ reviewCount: Int)
}
class FavouriteItemsViewController: UICollectionViewController {
var populationItems = false
var selectedSubCategoryId:Int = 0
var selectedCityId:Int = 1
var selectedCityLat: String!
var selectedCityLng: String!
var items = [ItemModel]()
var currentPage = 0
var loginUserId:Int = 0
weak var selectedCell : AnnotatedPhotoCell!
@IBOutlet weak var menuButton: UIBarButtonItem!
var defaultValue: CGPoint!
override func viewDidLoad() {
if self.revealViewController() != nil {
menuButton.target = self.revealViewController()
menuButton.action = #selector(SWRevealViewController.revealToggle(_:))
self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())
}
collectionView!.register(AnnotatedPhotoCell.classForCoder(), forSupplementaryViewOfKind: UICollectionElementKindSectionFooter, withReuseIdentifier: "AnnotatedPhotoCell")
if let layout = collectionView?.collectionViewLayout as? PinterestLayout {
layout.delegate = self
}
loadLoginUserId()
loadFavouriteItems()
defaultValue = collectionView?.frame.origin
animateCollectionView()
}
override func viewDidAppear(_ animated: Bool) {
updateNavigationStuff()
}
override var preferredStatusBarStyle : UIStatusBarStyle {
return UIStatusBarStyle.lightContent
}
override func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
loadFavouriteItems()
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
weak var itemCell = sender as? AnnotatedPhotoCell
weak var itemDetailPage = segue.destination as? ItemDetailViewController
itemDetailPage!.selectedItemId = Int((itemCell!.item?.itemId)!)!
itemDetailPage!.selectedShopId = Int((itemCell!.item?.itemShopId)!)!
itemDetailPage!.favRefreshLikeCountsDelegate = self
itemDetailPage!.favRefreshReviewCountsDelegate = self
selectedCell = itemCell
updateBackButton()
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return items.count
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
var cell : AnnotatedPhotoCell
cell = collectionView.dequeueReusableCell(withReuseIdentifier: "AnnotatedPhotoCell", for: indexPath) as! AnnotatedPhotoCell
cell.item = items[(indexPath as NSIndexPath).item]
let imageURL = configs.imageUrl + items[(indexPath as NSIndexPath).item].itemImage
cell.imageView?.loadImage(urlString: imageURL) { (status, url, image, msg) in
if(status == STATUS.success) {
print(url + " is loaded successfully.")
self.items[indexPath.item].itemImageBlob = image
}else {
print("Error in loading image" + msg)
}
}
cell.imageView.alpha = 0
cell.captionLabel.alpha = 0
UIView.animate(withDuration: 1, delay: 0, options: UIViewAnimationOptions.curveEaseIn, animations: {
cell.imageView.alpha = 1.0
cell.captionLabel.alpha = 1.0
}, completion: nil)
return cell
}
func updateBackButton() {
let backItem = UIBarButtonItem()
backItem.title = ""
navigationItem.backBarButtonItem = backItem
}
func updateNavigationStuff() {
self.navigationController?.navigationBar.topItem?.title = language.favouritePageTitle
self.navigationController?.navigationBar.titleTextAttributes = [ NSAttributedStringKey.font: UIFont(name: customFont.boldFontName, size: CGFloat(customFont.boldFontSize))!, NSAttributedStringKey.foregroundColor:UIColor.white]
self.navigationController!.navigationBar.barTintColor = Common.instance.colorWithHexString(configs.barColorCode)
}
func loadLoginUserId() {
let plistPath = Common.instance.getLoginUserInfoPlist()
let myDict = NSDictionary(contentsOfFile: plistPath)
if let dict = myDict {
loginUserId = Int(dict.object(forKey: "_login_user_id") as! String)!
print("Login User Id : " + String(loginUserId))
} else {
print("WARNING: Couldn't create dictionary from LoginUserInfo.plist! Default values will be used!")
}
}
func loadFavouriteItems() {
if self.currentPage == 0 {
_ = EZLoadingActivity.show("Loading...", disableUI: true)
}
Alamofire.request(APIRouters.GetFavouriteItems( loginUserId, configs.pageSize, self.currentPage)).responseCollection {
(response: DataResponse<[Item]>) in
if self.currentPage == 0 {
_ = EZLoadingActivity.hide()
}
if response.result.isSuccess {
if let items: [Item] = response.result.value {
if(items.count > 0) {
for item in items {
let oneItem = ItemModel(item: item)
self.items.append(oneItem)
self.currentPage+=1
}
}
}
self.collectionView!.reloadData()
} else {
print(response)
}
}
}
func animateCollectionView() {
moveOffScreen()
UIView.animate(withDuration: 1, delay: 0,
usingSpringWithDamping: 0.9,
initialSpringVelocity: 0.9, options: UIViewAnimationOptions.curveEaseOut, animations: {
self.collectionView?.frame.origin = self.defaultValue
}, completion: nil)
}
fileprivate func moveOffScreen() {
collectionView?.frame.origin = CGPoint(x: (collectionView?.frame.origin.x)!,
y: (collectionView?.frame.origin.y)! + UIScreen.main.bounds.size.height)
}
}
extension FavouriteItemsViewController : PinterestLayoutDelegate {
func collectionView(_ collectionView:UICollectionView, heightForPhotoAtIndexPath indexPath:IndexPath , withWidth width:CGFloat) -> CGFloat {
let item = items[(indexPath as NSIndexPath).item]
let boundingRect = CGRect(x: 0, y: 0, width: width, height: CGFloat(MAXFLOAT))
let size = CGSize(width: item.itemImageWidth, height: item.itemImageHeight)
var rect : CGRect
if item.itemImageBlob != nil {
rect = AVMakeRect(aspectRatio: item.itemImageBlob!.size, insideRect: boundingRect)
}else{
rect = AVMakeRect(aspectRatio: size, insideRect: boundingRect)
}
return rect.size.height
}
func collectionView(_ collectionView: UICollectionView, heightForAnnotationAtIndexPath indexPath: IndexPath, withWidth width: CGFloat) -> CGFloat {
let annotationPadding = CGFloat(4)
let annotationHeaderHeight = CGFloat(17)
let height = annotationPadding + annotationHeaderHeight + annotationPadding + 30
return height
}
}
extension FavouriteItemsViewController : FavRefreshLikeCountsDelegate, FavRefreshReviewCountsDelegate {
func updateLikeCounts(_ likeCount: Int) {
if selectedCell != nil {
selectedCell.lblLikeCount.text = "\(likeCount)"
}
}
func updateReviewCounts(_ reviewCount: Int) {
if selectedCell != nil {
selectedCell.lblReviewCount.text = "\(reviewCount)"
}
}
}
答案 0 :(得分：0)
您应该尝试检查ItemDetailViewController。 例如：
if segue.identifier == "ItemDetailVC" {
weak var itemCell = sender as? AnnotatedPhotoCell
weak var itemDetailPage = segue.destination as? ItemDetailViewController
...
}