SwiftUI - 仅设置一次状态变量后，警报显示两次 [英] SwiftUI - Alert displays twice after setting its state variable only once

问题描述

我想让这个按钮运行某个命令，如果它失败了，我想让它显示一个 Alert 说它失败了.它可以很好地执行此操作，除非警报显示时显示两次，但我只设置了一次.

I want to have this button run a certain command and if it fails, I want it to display an Alert saying it failed. It does this fine except when the alert displays, it displays twice but I only set it once.

这是我用来显示警报的两个状态变量:

Here are the two state variables I use to display the alert:

@State private var alert = false
@State private var alertView = Alert(
    title: Text("Well Hello There"),
    message: Text("You probably shouldn't be seeing this alert but if you are, hello there! (This is a bug)")
)

这是我的按钮:

Button(action: {
    DispatchQueue.global(qos: .background).async {
        if let command = action.command {
            let error = Connection.shared.run(command: command)
            if error != nil {
                self.alertView = Alert(
                    title: Text("Failed to Run Action"),
                    message: Text("An error occurred while attempting to \(action.label).")
                )
                print("Displaying alert") // This only gets printed once
                self.alert = true
            }
        }
    }
}) {
    Text(action.label)
}.alert(isPresented: self.$alert) {
    self.alertView
}

推荐答案

如果强行将 self.alert 设为 false 会怎样?

What if you set false to self.alert forcibly ?

.alert(isPresented: self.$alert) {
    self.alertView
}.onAppear{
    self.alert = false
 }

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