Ios UICollection视图的无限滚动
我尝试在我的应用程序中无限滚动,我从API调用数据,至少它在某种程度上起作用,但当我在“集合”视图中滚动时,它开始在下面填充,并剪切顶部的部分,因此我无法滚动回它们,然后在填充后它只是跳过并超出范围,这里有一些代码,请帮忙Ios UICollection视图的无限滚动,ios,swift,uicollectionview,scroll-paging,Ios,Swift,Uicollectionview,Scroll Paging,我尝试在我的应用程序中无限滚动,我从API调用数据,至少它在某种程度上起作用,但当我在“集合”视图中滚动时,它开始在下面填充,并剪切顶部的部分,因此我无法滚动回它们,然后在填充后它只是跳过并超出范围,这里有一些代码,请帮忙 var fetchMore = false var pageNumber = 0 var productPageString: String { if pageNumber == 0 { return "pageNumber=0&"
var fetchMore = false
var pageNumber = 0
var productPageString: String {
if pageNumber == 0 {
return "pageNumber=0&"
} else {
return "pageNumber=\(pageNumber)&"
}
}
func fetchProducts() {
fetchMore = false
let validatedTextString = UserDefaults.standard.object(forKey: "productsSearchValue")
let searchText = validatedTextString!
let urlString = APIConstants.baseurl + APIConstants.products + "?searchString=\(searchText)&\(productPageString)itemsPerPage=20"
guard let url = URL(string: urlString) else { return }
URLSession.shared.dataTask(with: url) { (data, response, error) in
if error != nil {
print(error!)
return
}
do {
let jsonData = try JSONDecoder().decode(ProductSearch.self, from: data!)
self.productSearchResults = [Products]()
for dictionary in jsonData.data {
let product = Products(productId: dictionary.productId, categoryId: dictionary.categoryId, storeId: dictionary.storeId, name: dictionary.name, description: dictionary.description, imageUrl: dictionary.imageUrl, price: dictionary.price)
self.productSearchResults?.append(product)
self.fetchMore = true
}
} catch let jsonError {
print(jsonError)
}
}.resume()
}
override func scrollViewDidScroll(_ scrollView: UIScrollView) {
let offsetY = scrollView.contentOffset.y
let contentHeight = scrollView.contentSize.height
if offsetY > contentHeight - scrollView.frame.height {
if fetchMore {
fetchProducts()
pageNumber += 1
}
}
}
它最初显示每页20个项目,但随着页码的增加,它会不断填充该特定页面中的其他内容,但我仍然只能每页查看20个项目。我希望能够滚动到上一个,而且,为什么它最终会自动将我带到最后?谢谢您需要重新加载
for dictionary in jsonData.data {
let product = Products(productId: dictionary.productId, categoryId: dictionary.categoryId, storeId: dictionary.storeId, name: dictionary.name, description: dictionary.description, imageUrl: dictionary.imageUrl, price: dictionary.price)
self.productSearchResults?.append(product)
}
self.fetchMore = true
DispatchQueue.main.async {
self.collectionView.reloadData()
}
你需要重新加载
for dictionary in jsonData.data {
let product = Products(productId: dictionary.productId, categoryId: dictionary.categoryId, storeId: dictionary.storeId, name: dictionary.name, description: dictionary.description, imageUrl: dictionary.imageUrl, price: dictionary.price)
self.productSearchResults?.append(product)
}
self.fetchMore = true
DispatchQueue.main.async {
self.collectionView.reloadData()
}
现在它可以工作了,我所要做的就是拆下电线
self.productSearchResults = [Products]()
没有必要现在它可以工作了,我所要做的就是拆下线路
self.productSearchResults = [Products]()
没有必要