iOS / SwiftUI 输入法（键盘）布局处理总结（AI版）

文章目录

[📘 iOS / SwiftUI 输入法（键盘）处理总结](#📘 iOS / SwiftUI 输入法（键盘）处理总结)
一、问题背景
二、输入框切换闪烁问题
- [❌ 错误原因](#❌ 错误原因)
- 解决办法
- [键盘动画（类似 Android Insets）](#键盘动画（类似 Android Insets）)
- - uikit
  - swiftUI

📘 iOS / SwiftUI 输入法（键盘）处理总结

一、问题背景

在 iOS / SwiftUI 开发中，常见输入法问题：

输入框切换时键盘闪烁
键盘弹出/收起动画不自然
无法像 Android WindowInsetsAnimation 一样平滑跟随

二、输入框切换闪烁问题

❌ 错误原因

swift 复制代码

focusedField = nil
focusedField = .password

解决办法

swift 复制代码

enum Field {
    case username
    case password
}

@FocusState private var focusedField: Field?

TextField("用户名", text: $username)
    .focused($focusedField, equals: .username)

SecureField("密码", text: $password)
    .focused($focusedField, equals: .password)

❗ 注意

不要先设为 nil

不要手动关闭键盘

使用系统焦点切换

键盘动画（类似 Android Insets）

uikit

swift 复制代码

@objc func keyboardWillChangeFrame(_ notification: Notification) {
    guard let userInfo = notification.userInfo else { return }
    
    let duration = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double ?? 0.25
    let curveRaw = userInfo[UIResponder.keyboardAnimationCurveUserInfoKey] as? UInt ?? 0
    let curve = UIView.AnimationOptions(rawValue: curveRaw << 16)
    
    let frame = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect ?? .zero
    let keyboardHeight = UIScreen.main.bounds.height - frame.origin.y
    
    UIView.animate(withDuration: duration, delay: 0, options: curve) {
        self.bottomConstraint.constant = keyboardHeight
        self.view.layoutIfNeeded()
    }
}

swiftUI

推荐

swift 复制代码

.safeAreaInset(edge: .bottom) {
    Color.clear.frame(height: 0)
}

combine

swift 复制代码

class KeyboardObserver: ObservableObject {
    @Published var height: CGFloat = 0
    
    private var cancellables = Set<AnyCancellable>()
    
    init() {
        NotificationCenter.default.publisher(for: UIResponder.keyboardWillChangeFrameNotification)
            .map { notification -> CGFloat in
                let frame = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect ?? .zero
                return UIScreen.main.bounds.height - frame.origin.y
            }
            .assign(to: \.height, on: self)
            .store(in: &cancellables)
    }
}

struct ContentView: View {
    @StateObject var keyboard = KeyboardObserver()
    
    var body: some View {
        VStack {
            Spacer()
            
            TextField("输入", text: .constant(""))
                .textFieldStyle(.roundedBorder)
        }
        .padding(.bottom, keyboard.height)
        .animation(.easeOut(duration: 0.25), value: keyboard.height)
    }
}