【发布时间】：2025-12-28 17:35:07
【问题描述】：
这是我的第一个 SwiftUI 应用。我做了很多搜索，但找不到解决方案。
我想展示不同类别的产品。为此，我有顶栏水平滚动菜单。选择任何类别时，我想显示每个类别的产品。加载第一类产品时，产品显示正确，但选择任何其他类别时，产品不会相应更新。但是，当我导航到任何其他视图并返回此视图时，产品显示正确。
我尝试了什么
我尝试了不同的视图来显示列表/滚动视图等产品。没有运气。
这是我的视图的完整代码
struct ProductListView: View {
@State var data:[Product]
@State private var categoryItems:[Product] = []
@State private var uniqueCategories:[Product] = []
@State private var numberOfRows:Int = 0
@State private var selectedItem:Int = 0
@State private var image:UIImage?
@EnvironmentObject var authState: AuthenticationState
@ViewBuilder
var body: some View {
NavigationView{
VStack{
ScrollView(.horizontal, showsIndicators: false) {
HStack {
ForEach(0..<self.data.removingDuplicates(byKey: { $0.category }).count) { i in
Text(self.data.removingDuplicates(byKey: { $0.category })[i].category)
.underline(self.selectedItem == i ? true:false, color: Color.orange)
.foregroundColor(self.selectedItem == i ? Color.red:Color.black)
//.border(Color.gray, width: 2.0)
.overlay(
RoundedRectangle(cornerRadius: 0.0)
.stroke(Color.init(red: 236.0/255.0, green: 240.0/255.0, blue: 241.0/255.0), lineWidth: 1).shadow(radius: 5.0)
).padding(.horizontal)
//.shadow(radius: 5.0)
.onTapGesture {
self.selectedItem = i
_ = self.getSelectedCategoryProducts()
print("Category Items New Count: \(self.categoryItems.count)")
}
Spacer()
Divider().background(Color.orange)
}
}
}
.frame(height: 20)
Text("My Products").foregroundColor(Color.red).padding()
Spacer()
if(self.data.count == 0){
Text("You didn't add any product yet.")
}
if (self.categoryItems.count>0){
ScrollView(.vertical){
ForEach(0..<Int(ceil(Double(self.categoryItems.count)/2.0)), id: \.self){ itemIndex in
return HStack() {
NavigationLink(destination:ProductDetailView(index: self.computeIndexes(currentIndex: itemIndex,cellNo: 1), data: self.categoryItems, image: UIImage())){
ProductTile(index: self.computeIndexes(currentIndex: itemIndex, cellNo: 1), data: self.categoryItems, image: UIImage())
}
NavigationLink(destination:ProductDetailView(index: self.computeIndexes(currentIndex: itemIndex,cellNo: 2), data: self.categoryItems, image: UIImage())){
ProductTile(index: self.computeIndexes(currentIndex: itemIndex, cellNo: 2), data: self.categoryItems, image: UIImage())
}
}.padding(.horizontal)
}
}.overlay(
RoundedRectangle(cornerRadius: 10.0)
.stroke(Color.init(red: 236.0/255.0, green: 240.0/255.0, blue: 241.0/255.0), lineWidth: 1).shadow(radius: 5.0)
)
}
}
}
.onAppear(perform: {
_ = self.getSelectedCategoryProducts()
//print("Loading updated products....")
if (self.authState.loggedInUser != nil){
FireStoreManager().loadProducts(userId: self.authState.loggedInUser!.uid) { (isSuccess, data) in
self.data = data
}
}
})
.padding()
}
func populateUniqueCategories() -> [Product] {
let uniqueRecords = self.data.reduce([], {
$0.contains($1) ? $0 : $0 + [$1]
})
print("Unique Items: \(uniqueRecords)")
return uniqueRecords
}
func getSelectedCategoryProducts() -> [Product] {
var categoryProducts:[Product] = []
self.data.forEach { (myProduct) in
if(myProduct.category == self.populateUniqueCategories()[selectedItem].category){
categoryProducts.append(myProduct)
}
}
self.categoryItems.removeAll()
self.categoryItems = categoryProducts
return categoryProducts
}
func computeIndexes(currentIndex:Int, cellNo:Int) -> Int {
var resultedIndex:Int = currentIndex
if (cellNo == 1){
resultedIndex = resultedIndex+currentIndex
print("Cell 1 Index: \(resultedIndex)")
}else{
resultedIndex = resultedIndex + currentIndex + 1
print("Cell 2 Index: \(resultedIndex)")
}
return resultedIndex
}
}
这是数组扩展
extension Array {
func removingDuplicates<T: Hashable>(byKey key: (Element) -> T) -> [Element] {
var result = [Element]()
var seen = Set<T>()
for value in self {
if seen.insert(key(value)).inserted {
result.append(value)
}
}
return result
}
}
如果您能帮我解决这个问题，我将不胜感激。 最好的问候
【问题讨论】：
标签： swift swiftui scrollview