SwiftUI Academy · 课时

展示工作表

使用工作表和绑定显示模态视图。

展示工作表 是 CoddyKit 上的免费 SwiftUI Academy 课时。这是第 1 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。

What Is a Sheet?

A sheet is a card that slides up from the bottom to show extra content, like a form or detail, without leaving your current screen. 📄

Sheets Need a Trigger

A sheet appears when a boolean state flips to true. You store that flag in your view and flip it when the user taps something.

@State private var showSheet = false

The .sheet Modifier

You attach .sheet to a view and bind it to your boolean. When the value is true, SwiftUI presents the content you return.

.sheet(isPresented: $showSheet) {
    Text("Hello from the sheet!")
}

The Dollar Sign Binding

The $ before showSheet passes a two-way binding, so SwiftUI can both read the flag and reset it to false when the sheet closes.

.sheet(isPresented: $showSheet) { DetailView() }

Opening the Sheet

Set the boolean to true from a button action and the sheet animates up automatically. You never call a present function yourself. ✨

Button("Show Details") {
    showSheet = true
}

Putting It Together

Combine the button, the state, and the .sheet modifier on one view and you have a working modal in just a few lines.

Button("Open") { showSheet = true }
    .sheet(isPresented: $showSheet) {
        Text("Sheet content")
    }

Dismissing a Sheet

Users can swipe a sheet down to close it. To dismiss it in code, read the dismiss action from the environment inside the sheet.

@Environment(\.dismiss) private var dismiss

Calling dismiss()

Give the sheet a Done button that calls dismiss(). This is the polite way to let users finish and return to the main screen.

Button("Done") { dismiss() }

Sheets Get Their Own State

A sheet is a normal SwiftUI view, so it can hold its own state, modifiers, and even another sheet. Treat it like any other screen.

Presenting With an Item

Use sheet(item:) when the sheet depends on a selected value. SwiftUI shows the sheet whenever that optional item is non-nil.

.sheet(item: $selectedBook) { book in
    BookDetail(book: book)
}

One Sheet at a Time

A view shows one sheet per modifier. For several modals, use separate flags or item bindings so they never collide on screen.

Quick Check

How do you tell SwiftUI to present a sheet?

Recap: Sheets

You learned that a sheet slides up from a boolean flag, attaches with .sheet, and closes via swipe or the dismiss action. Nice work! 🎉

常见问题解答

「展示工作表」课时是免费的吗？

是的 — 「展示工作表」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。

「展示工作表」这节课中我会学到什么？

使用工作表和绑定显示模态视图。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 1 节课，共 4 节。

「展示工作表」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。

此课程中的所有课时

← 返回 SwiftUI Academy