使用iOS SDK：
我有一个带UITextFields的UIView，可以启动键盘。我需要它能够：
启动键盘后，允许滚动UIScrollView的内容以查看其他文本字段自动“跳转”（通过向上滚动）或缩短
我知道我需要一个UIScrollView。我已经尝试将UIView的类更改为UIScrollView，但仍然无法上下滚动文本框。
我需要UIView和UIScrollView吗？一个在另一个里面吗？
要自动滚动到活动文本字段，需要执行哪些操作？
理想情况下，尽可能多的组件设置将在Interface Builder中完成。我只想编写需要的代码。
注意：我使用的UIView（或UIScrollView）是由一个选项卡（UITabBar）启动的，它需要正常工作。
我正在添加滚动条，只为键盘出现时使用。尽管不需要它，但我觉得它提供了一个更好的界面，例如，用户可以滚动和更改文本框。
当键盘上下移动时，我可以改变UIScrollView的框架大小。我只是在使用：
-(void)textFieldDidBeginEditing:(UITextField *)textField {
//Keyboard becomes visible
scrollView.frame = CGRectMake(scrollView.frame.origin.x,
scrollView.frame.origin.y,
scrollView.frame.size.width,
scrollView.frame.size.height - 215 + 50); // Resize
}
-(void)textFieldDidEndEditing:(UITextField *)textField {
// Keyboard will hide
scrollView.frame = CGRectMake(scrollView.frame.origin.x,
scrollView.frame.origin.y,
scrollView.frame.size.width,
scrollView.frame.size.height + 215 - 50); // Resize
}
然而，这不会自动“向上移动”或将可见区域中的下部文本字段居中，这是我真正想要的。
添加我的5美分：）
我总是喜欢使用tableView作为inputTextField或scrollView。结合通知，您可以轻松管理此类行为。（注意，如果您在tableView中使用静态单元格，则这种行为将自动为您管理。）
// MARK: - Notifications
fileprivate func registerNotificaitions() {
NotificationCenter.default.addObserver(self, selector: #selector(AddRemoteControlViewController.keyboardWillAppear(_:)),
name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(AddRemoteControlViewController.keyboardWillDisappear),
name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
fileprivate func unregisterNotifications() {
NotificationCenter.default.removeObserver(self)
}
@objc fileprivate func keyboardWillAppear(_ notification: Notification) {
if let keyboardHeight = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue.height {
view.layoutIfNeeded()
UIView.animate(withDuration: 0.3, animations: {
let heightInset = keyboardHeight - self.addDeviceButton.frame.height
self.tableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: heightInset, right: 0)
self.view.layoutIfNeeded()
}, completion: nil)
}
}
@objc fileprivate func keyboardWillDisappear() {
view.layoutIfNeeded()
UIView.animate(withDuration: 0.3, animations: {
self.tableView.contentInset = UIEdgeInsets.zero
self.view.layoutIfNeeded()
}, completion: nil)
}
下面是带有文本字段的滚动视图的简单解决方案，不需要任何约束或活动文本字段等。。。
override func viewWillAppear(_ animated: Bool){
super.viewWillAppear(animated)
registerForKeyboardNotifications();
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
deregisterFromKeyboardNotifications();
}
//MARK:- KEYBOARD DELEGATE METHODS
func registerForKeyboardNotifications(){
//Adding notifies on keyboard appearing
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillBeHidden(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
func deregisterFromKeyboardNotifications(){
//Removing notifies on keyboard appearing
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
func keyboardWasShown(notification: NSNotification){
var info = notification.userInfo!
let keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size
var contentInset:UIEdgeInsets = self.scrRegister.contentInset
contentInset.bottom = (keyboardSize?.height)!
scrRegister.contentInset = contentInset
}
func keyboardWillBeHidden(notification: NSNotification)
{
var contentInset:UIEdgeInsets = self.scrRegister.contentInset
contentInset.bottom = 0
scrRegister.contentInset = contentInset
}
使用ViewModifier快速切换UI
可以使用SwiftUI的ViewModifier。这要简单得多。
import SwiftUI
import Combine
struct KeyboardAwareModifier: ViewModifier {
@State private var keyboardHeight: CGFloat = 0
private var keyboardHeightPublisher: AnyPublisher<CGFloat, Never> {
Publishers.Merge(
NotificationCenter.default
.publisher(for: UIResponder.keyboardWillShowNotification)
.compactMap { $0.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue }
.map { $0.cgRectValue.height },
NotificationCenter.default
.publisher(for: UIResponder.keyboardWillHideNotification)
.map { _ in CGFloat(0) }
).eraseToAnyPublisher()
}
func body(content: Content) -> some View {
content
.padding(.bottom, keyboardHeight)
.onReceive(keyboardHeightPublisher) { self.keyboardHeight = $0 }
}
}
extension View {
func KeyboardAwarePadding() -> some View {
ModifiedContent(content: self, modifier: KeyboardAwareModifier())
}
}
在你看来
struct SomeView: View {
@State private var someText: String = ""
var body: some View {
VStack {
Spacer()
TextField("some text", text: $someText)
}.KeyboardAwarePadding()
}
}
KeyboardAwarePadding（）将自动为视图添加填充。它更优雅。
