Question

这应该很简单，但是我希望在条件为真时显示警报。（见下文）我已经看到很多地方，您使用按钮来触发警报，但是我只希望警报在条件发生时触发例如在简单的“ If”语句中满足。加载代码后应立即显示。

import SwiftUI

struct ContentView: View {
    @State private var showingAlert = false
    var score = 3

var body: some View {
    VStack{
        if score == 3 {

       showingAlert = true

        } .alert(isPresented: $showingAlert) {
        Alert(title: Text("Hello SwiftUI!"), message: Text("This is some detail message"), dismissButton: .default(Text("OK")))
    }

    }
    }

Answer 1

您可以在视图的init()方法中检查条件是否成立，然后设置showingAlert的初始值。

struct ContentView: View {
    @State private var showingAlert = false
    var score = 3

    init()
    {
        //check if condition is true
        if (true)
        {
            self._showingAlert = State(initialValue: true)
        }
    }

    var body: some View {
        VStack{
            EmptyView()
        } .alert(isPresented: self.$showingAlert) {
            Alert(title: Text("Hello SwiftUI!"), message: Text("This is some detail message"), dismissButton: .default(Text("OK")))
        }

    }
}

SwiftUI警报如何在简单的if语句中使其工作？

1 个答案: