当我第一次加载时，我的UICollectionView没有任何问题，我使用自定义布局和serachbar，当我搜索一些文本时，它崩溃抛出一个异常，即索引路径不存在的单元格，我使用搜索栏就像下一个代码：
import UIKit
import AVFoundation
class CategoryViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UISearchBarDelegate {
var ListArray : JSON! = []
var SelectedIds: [Int] = []
var SearchActive : Bool = false
var SearchArray = [Int]()
@IBOutlet weak var SearchCategories: UISearchBar!
@IBOutlet weak var CategoryCollection: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
if let layout = self.CategoryCollection.collectionViewLayout as? InterestsLayout {
layout.delegate = self
}
self.CategoryCollection.backgroundColor = UIColor.clearColor()
self.CategoryCollection.contentInset = UIEdgeInsets(top: 18, left: 3, bottom: 10, right: 3)
// Search Delegate
self.SearchCategories.delegate = self
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
self.LoadData()
}
func LoadData() {
MUBService.categoriesList(self) { (categories_list) -> () in
self.ListArray = categories_list
self.CategoryCollection.reloadData()
self.view.hideLoading()
}
}
func dismissKeyboard() {
view.endEditing(true)
self.SearchCategories.showsCancelButton = false
}
func searchBarTextDidBeginEditing(searchBar: UISearchBar) {
self.SearchCategories.showsCancelButton = true
self.SearchActive = true
}
func searchBarTextDidEndEditing(searchBar: UISearchBar) {
self.SearchActive = false
}
func searchBarCancelButtonClicked(searchBar: UISearchBar) {
self.SearchActive = false
self.dismissKeyboard()
}
func searchBarSearchButtonClicked(searchBar: UISearchBar) {
self.SearchActive = false
}
func searchBar(searchBar: UISearchBar, let textDidChange searchText: String) {
self.SearchArray = []
for (index, object) in self.ListArray["categories"] {
let name = object["name"].string!
if name.localizedStandardContainsString(searchText) == true {
self.SearchArray.append(Int(index)!)
}
}
if(self.SearchArray.count == 0){
self.SearchActive = false;
} else {
self.SearchActive = true;
}
self.CategoryCollection.reloadData()
}
}
extension CategoryViewController {
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
self.CategoryCollection?.collectionViewLayout.invalidateLayout()
return 1
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if(self.SearchActive && self.SearchArray.count > 0) {
return self.SearchArray.count
}
return self.ListArray["categories"].count
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("CategoryCell", forIndexPath: indexPath) as! CategoryCell
let row = indexPath.row
if(self.SearchActive && self.SearchArray.count > 0) {
let category = self.ListArray["categories"][self.SearchArray[row]]
cell.configureWithPhoto(category, selected: self.ListArray["selected"])
}else{
let category = self.ListArray["categories"][row]
cell.configureWithPhoto(category, selected: self.ListArray["selected"])
}
return cell
}
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
let cell = self.CategoryCollection.cellForItemAtIndexPath(indexPath) as! CategoryCell
cell.changeBackGroundColor()
if (cell.is_active == true){
self.SelectedIds.append(cell.id)
}else{
self.SelectedIds.removeObject(cell.id)
}
}
@IBAction func RegisterDidTouch(sender: AnyObject) {
MUBService.setMyCategories(self.SelectedIds, view_controller: self) { (categories_selected) -> () in
self.performSegueWithIdentifier("HomeTabBarFromCategoriesSegue", sender: self)
}
}
}
extension CategoryViewController : InterestsLayoutDelegate {
// 1. Returns the photo height
func collectionView(collectionView:UICollectionView, heightForPhotoAtIndexPath indexPath:NSIndexPath , withWidth width:CGFloat) -> CGFloat {
var row = indexPath.row
if(self.SearchActive && self.SearchArray.count > 0) {
row = self.SearchArray[row]
}
let category = self.ListArray["categories"][row]
let url = NSURL(string:category["image"].string!)
let data = NSData(contentsOfURL:url!)
let image = UIImage(data:data!)!
let boundingRect = CGRect(x: 0, y: 0, width: width, height: CGFloat(MAXFLOAT))
let rect = AVMakeRectWithAspectRatioInsideRect((image.size), boundingRect)
return rect.size.height
}
// 2. Returns the annotation size based on the text
func collectionView(collectionView: UICollectionView, heightForAnnotationAtIndexPath indexPath: NSIndexPath, withWidth width: CGFloat) -> CGFloat {
let annotationPadding = CGFloat(4)
let annotationHeaderHeight = CGFloat(17)
var row = indexPath.row
if(self.SearchActive && self.SearchArray.count > 0) {
row = self.SearchArray[row]
}
let category = self.ListArray["categories"][row]
let font = UIFont(name: "AvenirNext-Regular", size: 10)!
let rect = NSString(string: category["name"].string!).boundingRectWithSize(CGSize(width: width, height: CGFloat(MAXFLOAT)), options: .UsesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
let commentHeight = ceil(rect.height)
var height = annotationPadding + annotationHeaderHeight + commentHeight + annotationPadding
if (height != 70){
height = 70
}
return 70
}
}
我不明白发生了什么，非常感谢你的帮助
答案 0 :(得分：5)
我遇到了同样的问题。这里有一个解释：如果您使用自定义collectionViewLayout并且您有布局属性的缓存（最佳实践，因此您不必每次都计算属性），您必须覆盖invalidateLayout方法 in您的自定义布局类并清除缓存。
这是我的布局属性数组
private var cache = [UICollectionViewLayoutAttributes]()
这里是覆盖方法
override func invalidateLayout() {
super.invalidateLayout()
cache.removeAll()
}
我在textDidChange委托中调用布局失效
func searchBar(searchBar: UISearchBar, textDidChange searchText: String) {
if searchText.characters.count > 0 {
// search and reload data source
self.searchBarActive = true
self.filterContentForSearchText(searchText)
self.collectionView?.collectionViewLayout.invalidateLayout()
self.collectionView?.reloadData()
}else{
self.searchBarActive = false
self.collectionView?.collectionViewLayout.invalidateLayout()
self.collectionView?.reloadData()
}
}