在 ForEach 中更改刚刚单击的对象的值

如何解决在 ForEach 中更改刚刚单击的对象的值

当我单击顶部的单元格时，我只希望该对象上出现“已单击”文本。为什么我会在其他单元格上看到此文本？我该如何解决这个问题？

CellView

struct CellView: View {
    @Binding var text: String
    var body: some View {
        ZStack {
            RoundedRectangle(cornerRadius: 30)
                .foregroundColor(Color(UIColor.secondarySystemBackground))
                .frame(width: 300,height: 100)
            Text(text)
        }
    }
}

内容视图

struct ContentView: View {
    @State var text: String = ""
    var body: some View {
        vstack {
            ForEach(0 ..< 5) { item in
                
                Button(action: {
                    self.text = "Clicked"
                }) {
                    CellView(text: $text) 
                }
            }
        }
    }
}

解决方法

您会在其他单元格上看到文本，因为这是您在所有单元格中显示的内容。尝试这样的事情：

struct ContentView: View {
    @State var text: String = ""
    @State var selection: Int?
    
    var body: some View {
        VStack {
            ForEach(0 ..< 5) { item in
                Button(action: {
                    selection = item
                    text = "Clicked"
                }) {
                    if selection == item {
                        CellView(text: $text)
                    } else {
                        CellView(text: .constant(""))
                    }
                }
            }
        }
    }
}

,

您正在更新用于所有单元格的单个字符串 text。当它更改时，所有单元格都将使用该单个字符串进行更新。这里有几个选项：

你可以让 cell 负责存储和更新它自己的状态：

struct CellView: View {
    @State var text: String = ""

    var body: some View {
        Button(action: {
            self.text = "Clicked"
        }) {
            ZStack {
                RoundedRectangle(cornerRadius: 30)
                    .foregroundColor(Color(UIColor.secondarySystemBackground))
                    .frame(width: 300,height: 100)
                Text(text)
            }
        }
    }
}

struct CellClickContentView: View {
    var body: some View {
        VStack {
            ForEach(0 ..< 5) { item in
                CellView()
            }
        }
    }
}

或者您可以以某种方式在父视图中存储每个单元格的状态：

class CellState: ObservableObject,Identifiable {
    var id = UUID()
    @Published var text = ""
}

struct CellView: View {
    @ObservedObject var state: CellState

    var body: some View {
        ZStack {
            RoundedRectangle(cornerRadius: 30)
                .foregroundColor(Color(UIColor.secondarySystemBackground))
                .frame(width: 300,height: 100)
            Text(state.text)
        }
    }
}

struct CellClickContentView: View {
    @State var states: [CellState] = (0..<5).map { _ in CellState() }

    var body: some View {
        VStack {
            ForEach(states) { state in
                Button(action: {
                    state.text = "Clicked"
                }) {
                    CellView(state: state)
                }
            }
        }
    }
}