我正在创建一个座位布局，并希望使用委托以数组的形式从视图控制器类中获取坐标，但是在传递坐标并获得此错误时，我从视图控制器获取nil。
这是我的视图控制器
import UIKit
class BookViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UITableViewDelegate, UITableViewDataSource, SeatMapDelegate {
@IBOutlet weak var dropButton: UIButton!
@IBOutlet weak var dropDownOutlet: UITableView!
@IBOutlet weak var seatMapCollection: UICollectionView!
@IBOutlet weak var dateSelecterCollection: UICollectionView!
@IBOutlet weak var timeSelecterCollection: UICollectionView!
var selectedIndexPath: IndexPath!
var dateValue = ["1","2","3","4","10","6","7","8","9","5"]
var dayValue = ["Mon","Tue","Wed","Thu","Thu","Thu","Thu","Thu","Thu","Thu"]
var month = ["jan","feb","mar","apr","Thu","Thu","Thu","Thu","Thu","Thu"]
var venue = ["Smart Cinemaz, Rupnagar","Smart Cinemaz, Fatehgarh Sahib "]
var numberSection:Int = 10
var numberOfItems:Int = 15
var seatNumber = [Int]()
var columns = [[Int]]()
var rows = [[Int]]()
var col = [2,3]
var rowno = [8,9,16]
var col1 = [5,6,7,8,9,11,12]
var rowno1 = [9]
var sectionHeader: Array<Int> = [0,4,10]
var sectionHeading = ["Gold (₹180.00)","Silver (₹150.00)","Bronze (₹100.00)"]
var rowValue = ["A","B","C","D","E","F","G","H","I","J"]
var kCounter: Int = 0
override func viewDidLoad() {
super.viewDidLoad()
self.seatMapCollection.dataSource = self
self.seatMapCollection.delegate = self
self.seatMapCollection.reloadData()
self.seatMapCollection.maximumZoomScale = 2
self.seatMapCollection.minimumZoomScale = 0.50
self.view.sendSubview(toBack: seatMapCollection)
seatMapCollection.register(UINib(nibName: "HeaderMulticolumn", bundle: nil), forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "Header")
for seat in 0...numberOfItems-1{
seatNumber.append(seat + 1)
}
self.dateSelecterCollection.dataSource = self
self.dateSelecterCollection.delegate = self
self.timeSelecterCollection.dataSource = self
self.timeSelecterCollection.delegate = self
self.dropDownOutlet.delegate = self
self.dropDownOutlet.dataSource = self
dropButton.contentHorizontalAlignment = .left
/* let pinchGesture = UIPinchGestureRecognizer(target: self, action: #selector(pinchAction(sender:)))
seatMapCollection.addGestureRecognizer(pinchGesture)*/
columns.append(col)
columns.append(col1)
rows.append(rowno)
rows.append(rowno1)
}
@IBAction func dropDown(_ sender: Any) {
self.view.bringSubview(toFront: dropDownOutlet)
if dropDownOutlet.isHidden == true{
dropDownOutlet.isHidden = false
}else {
dropDownOutlet.isHidden = true
}
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if collectionView.tag == 1{
return 1
}else if collectionView.tag == 2{
return 1
}else{
return 15 + 2
}
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
if collectionView.tag == 1{
return 7
}else if collectionView.tag == 2{
return 5
}
else{
return 10 + 3
}
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
if collectionView.tag == 1 {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "DateSelecterCollectionViewCell", for: indexPath) as! DateSelecterCollectionViewCell
if (self.selectedIndexPath != nil && indexPath == self.selectedIndexPath){
cell.backgroundColor = UIColor.yellow
cell.dateOutlet.textColor = UIColor(red: 44/255, green: 150/255, blue: 208/255, alpha: 1)
cell.monthOutlet.textColor = UIColor(red: 44/255, green: 150/255, blue: 208/255, alpha: 1)
cell.dayOutlet.textColor = UIColor(red: 44/255, green: 150/255, blue: 208/255, alpha: 1)
}
else{
cell.backgroundColor = UIColor(red: 44/255, green: 150/255, blue: 208/255, alpha: 1)
cell.dateOutlet.textColor = UIColor.white
cell.monthOutlet.textColor = UIColor.white
cell.dayOutlet.textColor = UIColor.white
}
return cell
}else if collectionView.tag == 2{
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "TimeSelecterCollectionViewCell", for: indexPath) as! TimeSelecterCollectionViewCell
if (self.selectedIndexPath != nil && indexPath == self.selectedIndexPath){
cell.backgroundColor = UIColor.yellow
cell.timeOutlet.textColor = UIColor(red: 44/255, green: 150/255, blue: 208/255, alpha: 1)
}
else{
cell.backgroundColor = UIColor(red: 44/255, green: 150/255, blue: 208/255, alpha: 1)
cell.timeOutlet.textColor = UIColor.white
}
return cell
}
else {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "SeatMapCollectionViewCell", for: indexPath) as! SeatMapCollectionViewCell
cell.seatImage.isHidden = false
cell.seatImage.image = UIImage(named: "available")
for r1 in 0...rows.count-1{
for c1 in 0...columns.count-1{
if (r1 == c1){
for colum in 0...columns[c1].count-1 {
for ro in 0...rows[r1].count-1{
if indexPath.row == rows[r1][ro] && indexPath.section == columns[c1][colum]{
cell.isHidden = true
}
}
}
}
}
}
for i in 0...collectionView.numberOfSections-1{
for j in 0...sectionHeader.count-1{
// for k in 0...rowValue.count-1{
if indexPath.section != sectionHeader[j] && indexPath.row == 1{
cell.seatImage.isHidden=true
}
if indexPath.section != sectionHeader[j] && indexPath.row == 0 {
cell.seatDetail.isHidden = false
cell.seatDetail.text = rowValue[kCounter]
cell.seatDetail.textColor = UIColor.white
cell.seatImage.isHidden = true
}
if kCounter<rowValue.count-1{
kCounter=kCounter+1
}
// }
}
}
for i in 0...sectionHeader.count-1{
if indexPath.section==sectionHeader[i] && indexPath.row==0{
cell.seatDetail.isHidden=false
cell.seatDetail.text = sectionHeading[i]
cell.seatDetail.textColor = UIColor.white
cell.seatImage.isHidden = true
}
}
return cell
}
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if collectionView.tag == 1{
let cell = collectionView.cellForItem(at: indexPath) as! DateSelecterCollectionViewCell
if cell.isSelected == true{
cell.backgroundColor = UIColor.yellow
cell.dateOutlet.textColor = UIColor(red: 44/255, green: 150/255, blue: 208/255, alpha: 1)
cell.monthOutlet.textColor = UIColor(red: 44/255, green: 150/255, blue: 208/255, alpha: 1)
cell.dayOutlet.textColor = UIColor(red: 44/255, green: 150/255, blue: 208/255, alpha: 1)
}
self.selectedIndexPath = indexPath
}else if collectionView.tag == 2 {
let cell = collectionView.cellForItem(at: indexPath) as! TimeSelecterCollectionViewCell
self.selectedIndexPath = nil
cell.backgroundColor = UIColor.yellow
cell.timeOutlet.textColor = UIColor(red: 44/255, green: 150/255, blue: 208/255, alpha: 1)
}
}
func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
if collectionView.tag == 1{
let cell = collectionView.cellForItem(at: indexPath) as! DateSelecterCollectionViewCell
self.selectedIndexPath = nil
cell.backgroundColor = UIColor(red: 44/255, green: 150/255, blue: 208/255, alpha: 1)
cell.dateOutlet.textColor = UIColor.white
cell.monthOutlet.textColor = UIColor.white
cell.dayOutlet.textColor = UIColor.white
}
else if collectionView.tag == 2{
let cell = collectionView.cellForItem(at: indexPath) as! TimeSelecterCollectionViewCell
self.selectedIndexPath = nil
cell.backgroundColor = UIColor(red: 44/255, green: 150/255, blue: 208/255, alpha: 1)
cell.timeOutlet.textColor = UIColor.white
}
}
/* @objc func pinchAction(sender:UIPinchGestureRecognizer){
var scaleValue: CGFloat!
if sender.state == .changed || sender.state == .began {
if scaleValue == nil{
seatMapCollection.transform = CGAffineTransform.init(scaleX: sender.scale, y: sender.scale)
scaleValue = sender.scale
}else{
seatMapCollection.transform = CGAffineTransform.init(scaleX: scaleValue, y: scaleValue)
}
}
}*/
//
//
//
// Drop Down Section
//
//
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return venue.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "DropDownTableViewCell") as! DropDownTableViewCell
cell.venueDetails.text = "\(venue[indexPath.row])"
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let cell = tableView.cellForRow(at: indexPath) as! DropDownTableViewCell
dropButton.setTitle(cell.venueDetails.text, for: .normal)
tableView.isHidden = true
}
func getSectionCoordinates() -> Array<Int> {
return sectionHeader
}
}
这是我的自定义集合视图类：
import UIKit
protocol SeatMapDelegate: class {
func getSectionCoordinates() -> Array<Int>
}
class CustomCollectionViewLayout: UICollectionViewLayout {
var delegate: SeatMapDelegate?
var CELL_HEIGHT = 20.0
var CELL_WIDTH = 20.0
let STATUS_BAR = UIApplication.shared.statusBarFrame.height
var cache = [UICollectionViewLayoutAttributes]()
var contentSize = CGSize.zero
var cellAttrsDictionary = [UICollectionViewLayoutAttributes]()
var cellPadding = 2.0
var sectionHeader1: Array<Int>!
var sectionHeader = [0,4,9]
override var collectionViewContentSize: CGSize{
return self.contentSize
}
var interItemsSpacing: CGFloat = 8
// 5
var contentInsets: UIEdgeInsets {
return collectionView!.contentInset
}
override func prepare() {
var counts: Int = 0
sectionHeader1=(delegate?.getSectionCoordinates())!
// Cycle through each section of the data source.
if collectionView!.numberOfSections > 0 {
for section in 0...collectionView!.numberOfSections-1 {
// Cycle through each item in the section.
if collectionView!.numberOfItems(inSection: section) > 0 {
for item in 0...collectionView!.numberOfItems(inSection: section)-1 {
// Build the UICollectionVieLayoutAttributes for the cell.
let cellIndex = NSIndexPath(item: item, section: section)
/* let width: Double = 35.0
let height: Double = 35.0
CELL_WIDTH = (delegate?.collectionView(Width: width))!
CELL_HEIGHT = (delegate?.collectionView(Height: height))!*/
if counts<sectionHeader1.count {
if item == 0 && section == sectionHeader1[counts]{
let xPos = 0.0
let yPos = Double(section) * CELL_HEIGHT
let frame = CGRect(x: xPos, y: yPos, width: 15 * CELL_WIDTH, height: CELL_HEIGHT)
let cellFinalAttribute = frame.insetBy(dx:CGFloat(cellPadding) ,dy:CGFloat(cellPadding))
let cellAttributes = UICollectionViewLayoutAttributes(forCellWith: cellIndex as IndexPath)
cellAttributes.frame = cellFinalAttribute
//cellAttributes.frame = CGRect(x: xPos, y: yPos, width: CELL_WIDTH, height: CELL_HEIGHT)
cellAttrsDictionary.append(cellAttributes)
counts=counts+1
break
}
}
let xPos = Double(item) * CELL_WIDTH
let yPos = Double(section) * CELL_HEIGHT
let frame = CGRect(x: xPos, y: yPos, width: CELL_WIDTH, height: CELL_HEIGHT)
let cellFinalAttribute = frame.insetBy(dx:CGFloat(cellPadding) ,dy:CGFloat(cellPadding))
let cellAttributes = UICollectionViewLayoutAttributes(forCellWith: cellIndex as IndexPath)
cellAttributes.frame = cellFinalAttribute
//cellAttributes.frame = CGRect(x: xPos, y: yPos, width: CELL_WIDTH, height: CELL_HEIGHT)
cellAttrsDictionary.append(cellAttributes)
}
}
}
}
// Update content size.
let contentWidth = Double(collectionView!.numberOfItems(inSection: 0)) * CELL_WIDTH
let contentHeight = Double(collectionView!.numberOfSections) * CELL_HEIGHT
self.contentSize = CGSize(width: contentWidth, height: contentHeight)
}
override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
// Create an array to hold all elements found in our current view.
var attributesInRect = [UICollectionViewLayoutAttributes]()
// Check each element to see if it should be returned.
for cellAttributes in cellAttrsDictionary {
if rect.intersects(cellAttributes.frame) {
attributesInRect.append(cellAttributes)
}
}
// Return list of elements.
return attributesInRect
}
override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
return cellAttrsDictionary[indexPath.row]
}
override func shouldInvalidateLayout(forBoundsChange newBounds: CGRect) -> Bool {
return false
}
}
我不确定你想用sectionHeader1=(delegate?.getSectionCoordinates())!做什么，但你不能像那样使用代表。在你的函数onPrepare中，不能保证你的委托已经被实例化，并且你用!展开它，也就是当你得到异常时。