iOS键盘高度适应

背景

部分视图存在随键盘高度变化而自适应位置。所以需要监听键盘的高度变化。这里做个结合RxSwift做个简单封装。

使用参考

/// 底部栏键盘高度自适应
KeyboardHelper.shared.keyboardHeight.bind { [weak self] height in
    guard let self = self else { return }
    self.bottomView.snp.updateConstraints { make in
        let offsetHeight = height > 0 ? height - UIWindow().safeAreaInsets.bottom : height
        make.bottom.equalToSuperview().offset(-offsetHeight)
    }
    UIView.animate(withDuration: 0.3) {
        self.view.layoutIfNeeded()
    }
}.disposed(by: rx.disposeBag)

实现

import RxRelay

/// 键盘辅助类
class KeyboardHelper: NSObject {
    
    /// 单例
    public static let shared = KeyboardHelper()
    
    /// 键盘高度
    public let keyboardHeight: PublishRelay = .init()
    
    private override init() {
        super.init()
        self.setup()
    }
    
    /// 键盘通知监听
    private func setup() {
        // 键盘即将出现
        NotificationCenter.default.rx.notification(UIResponder.keyboardWillShowNotification).subscribe(onNext: { [weak self] value in
            guard let self = self else { return }
            let keyBoardEnd = (value.userInfo?["UIKeyboardFrameEndUserInfoKey"] as? CGRect) ?? .zero
            self.keyboardHeight.accept(keyBoardEnd.size.height)
        }).disposed(by: rx.disposeBag)
        
        // 键盘即将消失
        NotificationCenter.default.rx.notification(UIResponder.keyboardWillHideNotification).subscribe(onNext: { [weak self] _ in
            guard let self = self else { return }
            self.keyboardHeight.accept(0)
        }).disposed(by: rx.disposeBag)
    }
    
}