gpt4 book ai didi

ios - 如何为 Collection View 创建多个数据源?

转载 作者:行者123 更新时间:2023-11-30 11:59:59 24 4
gpt4 key购买 nike

我有一个表格 View ,其中有两个单元格和这些单元格内的两个嵌入的 Collection View 。当我的应用程序尝试杜克第二个单元格时,它不断崩溃。我使用 Ash Furrows 教程作为该项目的基础,我将在此处链接该项目。 Tutorial link

如何解决这个问题?这是一些示例代码。

我有两个不同的单元格,每个单元格都有自己的带有此代码的类

    class TableViewCell: UITableViewCell {

@IBOutlet weak var collectionView: UICollectionView!

override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}

override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)

// Configure the view for the selected state
}

func setCollectionViewDataSourceDelegate <D: UICollectionViewDataSource & UICollectionViewDelegate> (dataSourceDelegate: D, forRow row: Int) {
collectionView.delegate = dataSourceDelegate
collectionView.dataSource = dataSourceDelegate
collectionView.tag = row
collectionView.reloadData()
}
}

这是代码的其余部分,显示我如何使单元格出队

    func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
if indexPath.section == 1 {
guard let tableViewCell = cell as? TableViewCell else {
return
}

tableViewCell.setCollectionViewDataSourceDelegate(dataSourceDelegate: self, forRow: indexPath.row)
}

if indexPath.section == 2 {
guard let tableViewCell2 = cell as? TableViewCell2 else {
return
}
tableViewCell2.setCollectionViewDataSourceDelegate(dataSourceDelegate: self, forRow: indexPath.row)
}


// we store the offset from here into the dictionary we created above
//tableViewCell.collectionViewOffset = storedOffsets[indexPath.row] ?? 0
}

func tableView(_ tableView: UITableView, didEndDisplaying cell: UITableViewCell, forRowAt indexPath: IndexPath) {
guard let tableViewCell = cell as? TableViewCell else { return }

storedOffsets[indexPath.row] = tableViewCell.collectionViewOffset
}

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print(indexPath)
}
}

// collectionView inside tableview cell

extension TabViewController1: UICollectionViewDelegate, UICollectionViewDataSource {

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return model[collectionView.tag].count
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {


if let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCell", for: indexPath) as? CollectionCell1 {
cell.backgroundColor = UIColor.gray
return cell
}

if let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCell2", for: indexPath) as? CollectionCell2 {
cell.backgroundColor = UIColor.purple
return cell
}

return UICollectionViewCell()
}

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("Collection view at row \(collectionView.tag) selected index path \(indexPath)")
}
}

任何帮助将不胜感激!

编辑:这是整个 View Controller 类

    class TabViewController1: UIViewController, UITableViewDelegate {

@IBOutlet private var tableView: UITableView!

var model: [[UIColor]] = []

// Here we create a new dictionary to store the offests, corresponding to their rows.
var storedOffsets = [Int: CGFloat]()

override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
print("tab1")

model = generateRandomData()
tableView.delegate = self
}

override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
print("tab 1 viewWillAppear")
}

override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}

func generateRandomData() -> [[UIColor]] {
let numberOfRows = 20
let numberOfItemsPerRow = 15

return (0..<numberOfRows).map { _ in
return (0..<numberOfItemsPerRow).map { _ in UIColor.randomColor() }
}
}
}

extension TabViewController1: UITableViewDataSource {

func numberOfSections(in tableView: UITableView) -> Int {
return 5
}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if section == 3 {
return 1
}
if section == 4 {
return 6
} else {
return 1
}
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

if indexPath.section == 0 {
let cell = tableView.dequeueReusableCell(withIdentifier: "featuredPicture", for: indexPath) as! FeaturedVideoTableViewCell
return cell
}

if indexPath.section == 1 {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! TableViewCell
return cell
}


if indexPath.section == 2 {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell2", for: indexPath) as! TableViewCell2
return cell
}

if indexPath.section == 3 {

let cell = tableView.dequeueReusableCell(withIdentifier: "headerCell", for: indexPath) as! HeaderTableViewCell
return cell
}

if indexPath.section == 4 {

let cell = tableView.dequeueReusableCell(withIdentifier: "categoryCell", for: indexPath) as! CategoryTableViewCell
return cell
}

return UITableViewCell()

}

// titleForHeaderInSection doesnt get called because I implemented the bottom method which is `viewForHeaderInSection`.
// I am trying to figure out if we can use both at the same time
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {

if section == 0 {
return "Featured"
}

if section == 1 {
return "Cool Stuff"
}

if section == 2 {
return "Awesome Stuff"
}

if section == 3 {
return "nothing"
}

if section == 4 {
return "Categories"
}

return String()
}

// viewForHeaderInSection
// func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
// if section == 3 {
// let cell = tableView.dequeueReusableCell(withIdentifier: "headerCell") as! HeaderTableViewCell
// return cell
// }
// return UIView()
// }

// func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
// if section == 3 {
// return 50
// }
// return CGFloat()
// }

func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
if indexPath.section == 1 {
guard let tableViewCell = cell as? TableViewCell else {
return
}

tableViewCell.setCollectionViewDataSourceDelegate(dataSourceDelegate: self, forRow: indexPath.row)
}

if indexPath.section == 2 {
guard let tableViewCell2 = cell as? TableViewCell2 else {
return
}
tableViewCell2.setCollectionViewDataSourceDelegate(dataSourceDelegate: self, forRow: indexPath.row)
}


// we store the offset from here into the dictionary we created above
//tableViewCell.collectionViewOffset = storedOffsets[indexPath.row] ?? 0
}

func tableView(_ tableView: UITableView, didEndDisplaying cell: UITableViewCell, forRowAt indexPath: IndexPath) {
guard let tableViewCell = cell as? TableViewCell else { return }

storedOffsets[indexPath.row] = tableViewCell.collectionViewOffset
}

func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
if indexPath.section == 0 {
return 350
}

if indexPath.section == 1 {
return 130
}

if indexPath.section == 2 {
return 200
}

if indexPath.section == 3 {
return 50
}

if indexPath.section == 4 {
return 220
}

return CGFloat()
}

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print(indexPath)
}
}

// collectionView inside tableview cell

extension TabViewController1: UICollectionViewDelegate, UICollectionViewDataSource {

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return model[collectionView.tag].count
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

if let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCell", for: indexPath) as? CollectionCell1 {
cell.backgroundColor = UIColor.gray
return cell
}

if let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCell2", for: indexPath) as? CollectionCell2 {
cell.backgroundColor = UIColor.purple
return cell
}

return UICollectionViewCell()
}


func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("Collection view at row \(collectionView.tag) selected index path \(indexPath)")
}
}

最佳答案

如果没有看到你在哪里注册你的单元格类,很难肯定地说,但我怀疑你在 -cellForRow 中得到了除了 TableViewCell2 (或者它实际上崩溃的地方)以外的东西......或者 - cellForItemAt...方法。你所有的力气解开(!)都可能会导致问题。在崩溃之前放置一个断点,并检查您实际上从 -dequeueReusableCell 调用中返回了什么。

关于ios - 如何为 Collection View 创建多个数据源?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/47362169/

24 4 0
Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
广告合作:1813099741@qq.com 6ren.com