我最近发现自己在开发消息应用程序时也遇到了类似的情况。我创建了一个自定义的UIView，它粘在键盘顶部，并自动完成您所需的大部分操作

消息生成器视图

（来源：thegamengine.org）

这个项目背后的想法是创建类似于iMessage合成视图AKA的功能：

当键盘关闭时，会粘在键盘顶部并移动到屏幕底部处理文本中的更改控制柄旋转

为了调整/重新配置UIScrollView，您需要使用以下可选委托方法：

-（void）messageComposerFrameDidChange：（CGRect）帧，动画持续时间：（float）持续时间；

每当更改帧（调整大小、重新定位、旋转）时都会调用它，并且还会提供动画持续时间。您可以根据需要使用此信息调整UIScrollView的框架和内容插图的大小。

首先，我为您的页面推荐一个更好的设计，这样就不需要滚动视图。如果您有许多文本字段，您仍然不必使用ScrollView，这只会使事情变得复杂。您只需在控制器原始视图的顶部添加一个容器UIView，然后将这些文本字段放在该视图上。当键盘显示或消失时，只需使用动画移动此容器视图。

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。

刚找到这个类：

https://github.com/OliverLetterer/SLScrollViewKeyboardSupport

到目前为止，它在iPhone上运行得很好，包括动画和正确的偏移。

要使用它，只需添加到viewDidLoad：

self.support = [[SLScrollViewKeyboardSupport alloc] initWithScrollView:self.scrollView];

这可以通过以下代码行使用约束简单地实现

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(keyboardWillShow:)
                                                     name:UIKeyboardWillShowNotification
                                                   object:nil];
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(keyboardWillHide:)
                                                     name:UIKeyboardWillHideNotification
                                                   object:nil];
}

- (void)keyboardWillShow:(NSNotification *)notification {
    [self adjustTextViewByKeyboardState:YES keyboardInfo:[notification userInfo]];
}

- (void)keyboardWillHide:(NSNotification *)notification {
    [self adjustTextViewByKeyboardState:NO keyboardInfo:[notification userInfo]];
}

- (void)viewDidDisappear:(BOOL)animated {
    [[NSNotificationCenter defaultCenter] removeObserver:self];
    [super viewDidDisappear:animated];
}

- (void)adjustTextViewByKeyboardState:(BOOL)showKeyboard keyboardInfo:(NSDictionary *)info {
    CGRect keyboardFrame = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    CGFloat height = keyboardFrame.size.height;
    self.constraintToAdjust.constant = height;        UIViewAnimationCurve animationCurve = [info[UIKeyboardAnimationCurveUserInfoKey] unsignedIntegerValue];
    UIViewAnimationOptions animationOptions = UIViewAnimationOptionBeginFromCurrentState;
    if (animationCurve == UIViewAnimationCurveEaseIn) {
        animationOptions |= UIViewAnimationOptionCurveEaseIn;
    }
    else if (animationCurve == UIViewAnimationCurveEaseInOut) {
        animationOptions |= UIViewAnimationOptionCurveEaseInOut;
    }
    else if (animationCurve == UIViewAnimationCurveEaseOut) {
        animationOptions |= UIViewAnimationOptionCurveEaseOut;
    }
    else if (animationCurve == UIViewAnimationCurveLinear) {
        animationOptions |= UIViewAnimationOptionCurveLinear;
    }
    [UIView animateWithDuration:[[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue] delay:0 options:animationOptions animations:^{
        [self.view layoutIfNeeded];
    }                completion:nil];
}

您需要以编程方式添加具有特定帧大小的滚动视图。您必须在.h文件中添加UIScrollViewDelegate。您必须启用滚动视图，以便在viewDidLoad（）中编写以下内容。

scrollview.scrollEnabled=YES;
scrollview.delegate=self;

scrollview.frame = CGRectMake(x,y,width,height);
//---set the content size of the scroll view--- 

[scrollview setContentSize:CGSizeMake(height,width)];

这样，可以添加x、y、宽度和高度值。