【问题标题】:SwiftUI .onDelete get var from ForEachSwiftUI .onDelete 从 ForEach 获取 var
【发布时间】:2020-08-12 08:49:19
【问题描述】:

我有这个代码:

struct CreateInfo: Identifiable {
    var id: String
    var name: String
    var time: String
    var day: String
    var isDeleted: Bool
}

struct ZettelView: View {
    
    @State var zettelInfos = [CreateInfo]()
    
    @State private var showingAlert = false

    @State private var savedValueForDeleteFunction: CreateInfo
    
    func createNewInfo() {
        
        var arr = [[String]]()
        arr = getZettelData()
                
        
        for x in arr {
            zettelInfos.append(CreateInfo(id: "\(x[0])", name: "\(x[1])", time: "\(x[2])", day: "\(x[3])", isDeleted: false))
        }
        
        self.executeThisAsyncThing = false
        
   }
    
    
    @State var executeThisAsyncThing: Bool = true
    
    
    
    var body: some View {
    
        
        DispatchQueue.main.async {
            if self.executeThisAsyncThing {
                self.createNewInfo()
            }
        }
            
        
        return VStack {
            
            //New - testing
            NavigationView {
                List {
                    ForEach(zettelInfos) { x in
                                                
                        
                        NavigationLink(destination: zettelDetailView(uuid: x.id, info: x)) {
                            Text("\(x.id)")
                            
                        }

                        
                    }.onDelete(perform: delete)
                    
                }.navigationBarTitle("Einkaufszettel")
                .navigationBarItems(trailing: Button(action: {
                    self.addRow()
                }) {
                    Image(systemName: "plus.app.fill")
                })
                
            }

         .alert(isPresented: $showingAlert) {
                Alert(title: Text(" meImportantssage"), message: Text("Wear sunscreen"), dismissButton: .default(Text("Got it!")))
            }
            
            
            
        }

        
    }
    
    func delete(at offsets: IndexSet) {
                
        zettelInfos.remove(atOffsets: offsets)
        self.showingAlert = true
                
    }
    
    
        private func addRow() {
            
            let dateAndTime = Date()
            let dfDay = DateFormatter()
            let dfTime = DateFormatter()
            
            dfDay.dateFormat = "dd.MM.yyyy"
            dfTime.dateFormat = "HH:mm:ss"

            let day = dfDay.string(from: dateAndTime)
            let time = dfTime.string(from: dateAndTime)
            
            
            let x = CreateInfo(id: UUID().uuidString, name: "Neuer Zettel", time: time, day: day, isDeleted: false)
            
            saveZettelData(x: x)
            zettelInfos.append(x)
            

        }
    


}

所以我的问题是,如何将 ForEach 中的 x 变量解析为删除函数?

我为什么要这个? -> foreach 中的 x 变量有一个 UUID,我需要来自 x 的 UUID

有没有人知道一种方法,我如何从x 获取 UUID?

这是我的第一个 swift 应用程序,我正在努力学习它,但在某些情况下,它与我所知道的其他语言不同。通常我会将一个值解析为一个删除函数,然后遍历它以查找和删除特定的行/数据,但我猜想它是另一种方式。

【问题讨论】:

    标签: swift list for-loop swiftui


    【解决方案1】:

    这是一种方法

    func delete(at offsets: IndexSet) {
                
        let index = offsets[offsets.startIndex]
        let x = zettelInfos[index]
    
        // ... do anything needed with x.id now
    
        zettelInfos.remove(atOffsets: offsets)
        self.showingAlert = true
    }
    

    【讨论】:

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