SwiftUI Academy · 课时

使用状态切换可见性

使用布尔状态显示或隐藏视图。

使用状态切换可见性 是 CoddyKit 上的免费 SwiftUI Academy 课时。这是第 4 节课，共 4 节。你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。这是 SwiftUI Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 SwiftUI Academy 课程共包含 4 节课。

本课时的部分内容尚未翻译，以英文显示。

Show and Hide on Demand

A boolean @State can decide whether a view is visible. Flip it and SwiftUI shows or hides content for you. 👀

@State private var isVisible = false

Conditional Views

Inside body you can use a plain if statement. When the condition is true, SwiftUI includes the view; when false, it leaves it out.

if isVisible {
    Text("Now you see me")
}

A Button to Flip It

Toggle the boolean from a button action. The tiny toggle() method flips true to false and back.

Button("Toggle") {
    isVisible.toggle()
}

Wire It Together

Combine the button and the conditional Text in a VStack. Tapping reveals or hides the message as the state changes.

VStack {
    Button("Toggle") { isVisible.toggle() }
    if isVisible { Text("Hello") }
}

The Full View

Here is the complete view: one boolean, one button, and one conditionally shown Text.

struct PeekView: View {
    @State private var isVisible = false
    var body: some View {
        VStack {
            Button("Toggle") { isVisible.toggle() }
            if isVisible { Text("Hello") }
        }
    }
}

Toggle the Label Text

You can also drive a label from the same boolean, so the button reads Show or Hide depending on the current state.

Button(isVisible ? "Hide" : "Show") {
    isVisible.toggle()
}

Hidden vs Removed

An if statement truly removes the view from the layout. Other views shift to fill the space, unlike just making something transparent.

Keep Space with opacity

If you want a view to disappear but keep its spot, change its opacity instead of removing it with an if.

Text("Hi").opacity(isVisible ? 1 : 0)

Pair It with a Toggle Control

A SwiftUI Toggle control binds directly to the boolean, giving users a switch that flips your state without a custom button.

Toggle("Show details", isOn: $isVisible)

One Boolean, Many Reactions

The same state value can control several views at once. Change it in one place and every dependent view reacts together.

A Smoother Reveal

Wrap the change in withAnimation and the show or hide will fade in nicely. State plus a touch of animation feels polished.

withAnimation { isVisible.toggle() }

Quick Check

How do you make a Text appear only when a boolean state is true?

Recap

A boolean @State plus an if (or opacity) lets you show and hide views. Flip it with toggle and SwiftUI redraws to match. 🔀

常见问题解答

「使用状态切换可见性」课时是免费的吗？

是的 — 「使用状态切换可见性」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 SwiftUI Academy 课程的其余内容，请升级到 CoddyKit PRO。 SwiftUI Academy 课程共包含 4 节课。

「使用状态切换可见性」这节课中我会学到什么？

使用布尔状态显示或隐藏视图。你通过在浏览器中直接运行的动手代码来练习 SwiftUI Academy，全天候 AI 导师会在你学习这节课的过程中回答你的问题。

学习 SwiftUI Academy 需要有经验吗？

无需任何先前经验。CoddyKit 上的 SwiftUI Academy 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。这是第 4 节课，共 4 节。

「使用状态切换可见性」课时需要多长时间？

大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。

我能在这节 SwiftUI Academy 课中编写并运行代码吗？

能。每节 SwiftUI Academy 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。

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