将相同的视图控制器推入堆栈有奇怪的行为
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【中文标题】将相同的视图控制器推入堆栈有奇怪的行为【英文标题】：pushing the same viewcontroller onto stack has odd behaviour going back 【发布时间】：2017-01-29 11:20:16 【问题描述】：我在导航控制器中嵌入了一个 AccountViewController。
这就像一个包含关注者列表的 AccountProfile 屏幕
当我点击关注者时，我将相同的 ViewController 推到顶部，并填充该用户点击的详细信息。
当我在导航栏中回击时，我希望返回到以前的用户个人资料屏幕，但是它在丢弃顶部后显示新点击的用户屏幕。
这就是我正在做的推动
let userId = self.followerUsers[pickedCellIndexPathRow].userId!
let newUserVC = self.storyboard?.instantiateViewController(withIdentifier: "AccountVC") as! AccountViewController
newUserVC.userId = userId
self.navigationController?.pushViewController(newUserVC, animated: true)
这很好，但如前所述，返回会丢弃屏幕，但旧屏幕中有新用户的详细信息
我该如何解决它 - 基本上我应该能够堆叠配置文件并返回它们
AccountViewController：
import UIKit
import SwiftEventBus
class AccountViewController: UIViewController,UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout, SegmentClickedDelegate
func userClickedSegment(segmentNumber: Int)
segmentIndex = segmentNumber
var segmentIndex = 0
didSet
collectionView.reloadData()
@IBOutlet weak var collectionView: UICollectionView!
override func viewDidLoad()
super.viewDidLoad()
collectionView.dataSource = self
collectionView.delegate = self
let layout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout
layout?.sectionHeadersPinToVisibleBounds = true
var model = UserProfileViewModel()
var user: UserResponse?
didSet
containerCell.user = self.user
mapUserPhotos()
mapFollowers()
mapFollowing()
if collectionView != nil
collectionView.reloadData()
public var userId : String=""
didSet
model.getUserInfo(userId: userId)
SwiftEventBus.onMainThread(self, name:EventBus.GetUserEvent) result in
let user = result.object as! UserResponse
self.user = user
var reviews = [UserReviews]()
didSet
if collectionView != nil
//collectionView.reloadData()
var followingUsers = [UserFollowing]()
didSet
if collectionView != nil
// collectionView.reloadData()
var followerUsers = [UserFollowers]()
didSet
if collectionView != nil
//collectionView.reloadData()
func mapUserPhotos()
if let result = user
self.reviews = result .reviews!
func mapFollowers()
if let result = user
self.followerUsers = result .followers!
func mapFollowing()
if let result = user
self.followingUsers = result .following!
// number of sections is 2. Section above search and below search
func numberOfSections(in collectionView: UICollectionView) -> Int
return 2
//number of items for each section. Section above search will have only one and below search will be dynamic as per images we have
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
if section == 0
return 1
else
switch segmentIndex//segmentedControl.selectedSegmentIndex
case 0 :
return self.reviews.count
case 1:
return self.followerUsers.count
case 2:
return self.followingUsers.count
default://break
return self.reviews.count
private struct UserPostsBoard
static let PhotoCellIdentifier = "UserPhotoCell"
static let FollowerCellIdentifier = "FollowerCell"
static let FollowingCellIdentifier = "FollowingCell"
var containerCell = AboveSearchCollectionViewCell()
// cell for item at given indexpath: if section is 0 then return cell above search, if section is 1 then return cell below search
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
if indexPath.section == 0
// above search cell
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "aboveSearch", for: indexPath)
containerCell = (cell as? AboveSearchCollectionViewCell)!
containerCell.user = self.user
return cell
else
// below search cell
print("self.segmentIndex\(self.segmentIndex)")
//switch item//self.segmentIndex//segmentedControl.selectedSegmentIndex
switch self.segmentIndex//segmentedControl.selectedSegmentIndex
case 0 :
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: UserPostsBoard.PhotoCellIdentifier, for: indexPath)
let item = self.reviews[indexPath.row]
if let itemCell = cell as? UserPhotoCollectionViewCell
itemCell.photo = item
return cell
case 1:
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: UserPostsBoard.FollowerCellIdentifier, for: indexPath)
let item = self.followerUsers[indexPath.row]
if let itemCell = cell as? UserFollowersCollectionViewCell
itemCell.user = item
return cell
case 2:
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: UserPostsBoard.FollowingCellIdentifier, for: indexPath)
let item = self.followingUsers[indexPath.row]
if let itemCell = cell as? UserFollowingCollectionViewCell
itemCell.user = item
return cell
default://break
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: UserPostsBoard.PhotoCellIdentifier, for: indexPath)
let photoItem = self.self.reviews[indexPath.row]
if let photoCell = cell as? UserPhotoCollectionViewCell
photoCell.photo = photoItem
return cell
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath)
if collectionView == self.collectionView
//pickedCell = collectionView.cellForItem(at: indexPath)
//pickedCellIndexPathRow = indexPath.row
//self.performSegue(withIdentifier: "showUserRating", sender: self)
pickedCellIndexPathRow = indexPath.row
switch segmentIndex//segmentedControl.selectedSegmentIndex
case 0 : self.performSegue(withIdentifier: "showUserRating", sender: self)
case 1 : //self.performSegue(withIdentifier: "showFollower", sender: self)
let userId = self.followerUsers[pickedCellIndexPathRow].userId!
let newUserVC = self.storyboard?.instantiateViewController(withIdentifier: "AccountVC") as! AccountViewController
newUserVC.userId = userId
self.navigationController?.pushViewController(newUserVC, animated: true)//push(avc, animated: true, completion: nil)
//self.navigationController?.popViewController(animated: false)
//case 2 : self.performSegue(withIdentifier: "showFollower", sender: self)
default: break
var pickedCellIndexPathRow = 0
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize
if indexPath.section == 0
return CGSize(width: collectionView.frame.width, height: 200)
else
switch segmentIndex//segmentedControl.selectedSegmentIndex
case 0 :
let width = (collectionView.frame.width / 3) - 1
return CGSize(width: width, height: width)
default:
return CGSize(width: collectionView.frame.width, height: 80)
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat
return 1.0
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat
return 1.0
// implementation of function viewForSupplementaryElementOfKind, for section header of collectionView
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView
// returning the search bar for header
let segmentView = collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "search", for: indexPath) as! TopBarCollectionReusableView
segmentView.delegate = self
return segmentView
// size for header in section: since we have 2 sections, collectionView will ask size for header for both sections so we make section header of first section with height 0 and width 0 so it remains like invisible.
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize
// if section is above search bar we need to make its height 0
if section == 0
return CGSize(width: 0, height: 0)
// for section header i.e. actual search bar
return CGSize(width: collectionView.frame.width, height: 50)
【问题讨论】：
您需要发布更多信息或代码以便我们提供帮助。 我刚刚构建了一个简单的项目来尝试复制问题（带有一些文本的标签，以及一个推动第二个视图的按钮，以及您的代码的复制粘贴），但一无所获。我同意@BurhanuddinSunelwala：我们可能需要更多代码来解决这个问题。 @raklos：这里有很多东西要解压（对于初学者，我找不到为 segmentIndex 分配除 0 以外的值的位置）。有时间我看看能不能把问题提炼出来；同时，如果您没有得到答案，您可能需要在这些 didSets 中使用断点和打印，以确定您的原始 VC 的用户 ID 被更改的位置。 【参考方案1】：好的，我正在使用 SwiftEventBus，它会在网络调用返回响应时填充字段。
愚蠢的是，我忘了在课程中包含这个 - 所以没有它所有实例都会更新
override func viewWillDisappear(_ animated: Bool)
super.viewWillDisappear(animated)
SwiftEventBus.unregister(self)
【讨论】：
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