在Swift中執行3-4次后，DispatchQueue出現問題-有解無憂

我在下面有以下代碼向用戶顯示一條訊息然后消失。前 1 到 3 次嘗試一切正常，但超過此訊息視窗的任何內容都不會像之前的嘗試/要求那樣消失。

struct ContentView: View {
    @State var showingNotice = false

    var body: some View {
        ZStack {
            Button(action: {
                self.showingNotice = true
            }, label: {
                Text("Show Notice")
            })

            if showingNotice {
                FloatingNotice(showingNotice: $showingNotice)
            }
        }
        .animation(.easeInOut(duration: 1))
    }
}

struct FloatingNotice: View {
    @Binding var showingNotice: Bool

    var body: some View {
        VStack (alignment: .center, spacing: 8) {
            Image(systemName: "checkmark")
                .foregroundColor(.white)
                .font(.system(size: 48, weight: .regular))
                .padding(EdgeInsets(top: 20, leading: 5, bottom: 5, trailing: 5))
        
            Text("Review added")
                .foregroundColor(.white)
                .font(.callout)
                .padding(EdgeInsets(top: 0, leading: 10, bottom: 5, trailing: 10))
        }
        .background(Color.snackbar.opacity(0.75))
        .cornerRadius(5)
        .transition(.scale)
        .onAppear(perform: {
            DispatchQueue.main.asyncAfter(deadline: .now()   2, execute: {
                self.showingNotice = false
            })
        })
    }
}

誰能看到我缺少的東西或幫助弄清楚為什么它在多次執行后“停止”作業？

uj5u.com熱心網友回復：

有時onAppear不會被呼叫，所以你self.showingNotice = false不會被呼叫。因此，您可以做一件事，將您的延遲塊移動到按鈕內單擊它，如下所示。

struct ContentView: View {
    @State var showingNotice = false

    var body: some View {
        ZStack {
            Button(action: {
                self.showingNotice = true
                DispatchQueue.main.asyncAfter(deadline: .now()   2, execute: {
                    self.showingNotice = false
                })
            }, label: {
                Text("Show Notice")
            })

            if showingNotice {
                FloatingNotice(showingNotice: $showingNotice)
            }
        }
        .animation(.easeInOut(duration: 1))
    }
}

struct FloatingNotice: View {
    @Binding var showingNotice: Bool

    var body: some View {
        VStack (alignment: .center, spacing: 8) {
            Image(systemName: "checkmark")
                .foregroundColor(.white)
                .font(.system(size: 48, weight: .regular))
                .padding(EdgeInsets(top: 20, leading: 5, bottom: 5, trailing: 5))
               
        
            Text("Review added")
                .foregroundColor(.white)
                .font(.callout)
                .padding(EdgeInsets(top: 0, leading: 10, bottom: 5, trailing: 10))
        }
        .background(Color(.red))
        .cornerRadius(5)
        .transition(.scale)
        
    }
}

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