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。


当前回答

我迟到了一点。您应该在viewController上添加scrollView。

您必须实现以下2种方法。

TextField委托方法。

    - (void)textFieldDidBeginEditing:(UIView *)textField {
    [self scrollViewForTextField:reEnterPINTextField];
}

然后在委托方法中调用以下方法。

 - (void)scrollViewForTextField:(UIView *)textField {
    NSInteger keyboardHeight = KEYBOARD_HEIGHT;

    if ([textField UITextField.class]) {
        keyboardHeight += ((UITextField *)textField).keyboardControl.activeField.inputAccessoryView.frame.size.height;
    } 

    CGRect screenFrame = [UIScreen mainScreen].bounds;
    CGRect aRect = (CGRect){0, 0, screenFrame.size.width, screenFrame.size.height - ([UIApplication sharedApplication].statusBarHidden ? 0 : [UIApplication sharedApplication].statusBarFrame.size.height)};
    aRect.size.height -= keyboardHeight;
    CGPoint relativeOrigin = [UIView getOriginRelativeToScreenBounds:textField];
    CGPoint bottomPointOfTextField = CGPointMake(relativeOrigin.x, relativeOrigin.y + textField.frame.size.height);

    if (!CGRectContainsPoint(aRect, bottomPointOfTextField) ) {
        CGPoint scrollPoint = CGPointMake(0.0, bottomPointOfTextField.y -aRect.size.height);
        [contentSlidingView setContentOffset:scrollPoint animated:YES];
    }
}

其他回答

在这里,我找到了处理键盘的最简单的解决方案。

您只需复制粘贴到示例代码下面,然后更改文本字段或任何要向上移动的视图。

步骤-1

只需在控制器中复制粘贴以下两种方法

- (void)registerForKeyboardNotifications
{
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWasShown:)
                                                 name:UIKeyboardDidShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillBeHidden:)
                                                 name:UIKeyboardWillHideNotification object:nil];
}

- (void)deregisterFromKeyboardNotifications
{
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardDidHideNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}

步骤-2

在视图中注册和注销键盘通知WillAppear和viewWillDisappear方法。

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [self registerForKeyboardNotifications];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [self deregisterFromKeyboardNotifications];
    [super viewWillDisappear:animated];
}

步骤-3

灵魂部分来了,只要替换你的文本字段,然后改变高度你想向上移动多少。

- (void)keyboardWasShown:(NSNotification *)notification
{
    NSDictionary* info = [notification userInfo];
    CGSize currentKeyboardSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    //you need replace your textfield instance here
    CGPoint textFieldOrigin = self.tokenForPlaceField.frame.origin;
    CGFloat textFieldHeight = self.tokenForPlaceField.frame.size.height;

    CGRect visibleRect = self.view.frame;
    visibleRect.size.height -= currentKeyboardSize.height;

    if (!CGRectContainsPoint(visibleRect, textFieldOrigin))
    {
        //you can add yor desired height how much you want move keypad up, by replacing "textFieldHeight" below

        CGPoint scrollPoint = CGPointMake(0.0, textFieldOrigin.y - visibleRect.size.height  + textFieldHeight); //replace textFieldHeight to currentKeyboardSize.height, if you want to move up with more height
        [self.scrollView setContentOffset:scrollPoint animated:YES];
    }
}

- (void)keyboardWillBeHidden:(NSNotification *)notification
{
    [self.scrollView setContentOffset:CGPointZero animated:YES];
}

参考:好吧,请感谢这位分享了这个漂亮的代码片段、干净的解决方案的人。

希望这对外面的人会很有帮助。

这是独立于设备的偏移计算。获取键盘和文本字段之间的重叠高度:

func keyboardShown(notification: NSNotification) {
    let info  = notification.userInfo!
    let value: AnyObject = info[UIKeyboardFrameEndUserInfoKey]!

    let rawFrame = value.CGRectValue
    let keyboardFrame = view.convertRect(rawFrame, fromView: nil)

    let screenHeight = UIScreen.mainScreen().bounds.size.height;
    let Ylimit = screenHeight - keyboardFrame.size.height
    let textboxOriginInSuperview:CGPoint = self.view.convertPoint(CGPointZero, fromCoordinateSpace: lastTextField!)

    self.keyboardHeight = (textboxOriginInSuperview.y+self.lastTextField!.frame.size.height) - Ylimit

    if(self.keyboardHeight>0){
        self.animateViewMoving(true, moveValue: keyboardHeight!)
    }else{
        keyboardHeight=0
    }
}

keyBoardHeight是偏移量。

这是我的“仅UITextView扩展”解决方案,基于Paul Hudson@twostraws的解决方案(向他和这里所有类似答案的作者致敬)。

import UIKit

extension UITextView {
    
    func adjustableForKeyboard() {
        let notificationCenter = NotificationCenter.default
        
        notificationCenter.addObserver(self, selector: #selector(adjustForKeyboard), name: UIResponder.keyboardWillHideNotification, object: nil)
        notificationCenter.addObserver(self, selector: #selector(adjustForKeyboard), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
    }
    
    @objc private func adjustForKeyboard(notification: Notification) {
        guard let keyboardValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else {
            return
        }

        let keyboardScreenEndFrame = keyboardValue.cgRectValue
        let keyboardViewEndFrame = convert(keyboardScreenEndFrame, from: window)
        
        if notification.name == UIResponder.keyboardWillHideNotification {
            contentInset = .zero
        } else {
            contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardViewEndFrame.height - safeAreaInsets.bottom, right: 0)
        }

        scrollIndicatorInsets = contentInset
        scrollRangeToVisible(selectedRange)
    }
}

用法:

override func viewDidLoad() {
    super.viewDidLoad()
    
    textView.adjustableForKeyboard()
}

-快速用户界面

仅显示活动文本字段

这将充分移动视图,以避免仅隐藏活动的TextField。

struct ContentView: View {
    @ObservedObject private var kGuardian = KeyboardGuardian(textFieldCount: 3)
    @State private var name = Array<String>.init(repeating: "", count: 3)

    var body: some View {

        VStack {
            Group {
                Text("Some filler text").font(.largeTitle)
                Text("Some filler text").font(.largeTitle)
            }

            TextField("text #1", text: $name[0], onEditingChanged: { if $0 { self.kGuardian.showField = 0 } })
                .textFieldStyle(RoundedBorderTextFieldStyle())
                .background(GeometryGetter(rect: $kGuardian.rects[0]))

            TextField("text #2", text: $name[1], onEditingChanged: { if $0 { self.kGuardian.showField = 1 } })
                .textFieldStyle(RoundedBorderTextFieldStyle())
                .background(GeometryGetter(rect: $kGuardian.rects[1]))

            TextField("text #3", text: $name[2], onEditingChanged: { if $0 { self.kGuardian.showField = 2 } })
                .textFieldStyle(RoundedBorderTextFieldStyle())
                .background(GeometryGetter(rect: $kGuardian.rects[2]))

            }.offset(y: kGuardian.slide).animation(.easeInOut(duration: 0.25))
    }

}

显示所有文本字段

如果键盘显示其中任何一个文本字段,则会将所有文本字段上移。但只有在需要时。如果键盘不隐藏文本字段,它们将不会移动。

struct ContentView: View {
    @ObservedObject private var kGuardian = KeyboardGuardian(textFieldCount: 1)
    @State private var name = Array<String>.init(repeating: "", count: 3)

    var body: some View {

        VStack {
            Group {
                Text("Some filler text").font(.largeTitle)
                Text("Some filler text").font(.largeTitle)
            }

            TextField("enter text #1", text: $name[0])
                .textFieldStyle(RoundedBorderTextFieldStyle())

            TextField("enter text #2", text: $name[1])
                .textFieldStyle(RoundedBorderTextFieldStyle())

            TextField("enter text #3", text: $name[2])
                .textFieldStyle(RoundedBorderTextFieldStyle())
                .background(GeometryGetter(rect: $kGuardian.rects[0]))

        }.offset(y: kGuardian.slide).animation(.easeInOut(duration: 0.25))
    }

}

两个示例都使用相同的通用代码:GeometryGetter和KeyboardGuardian灵感来自@kontiki

几何图形获取器

这是一个吸收其父视图的大小和位置的视图。在这里封装描述为了实现这一点,它在.background修饰符中被调用。这是一个非常强大的修改器,而不仅仅是一种装饰视图背景的方法。当将视图传递给.background(MyView())时,MyView将获得修改后的视图作为父视图。使用GeometryReader可以使视图了解父对象的几何图形。

例如:Text(“hello”).background(GeometryGetter(rect:$bounds))将使用Text视图的大小和位置并使用全局坐标空间填充变量边界。

struct GeometryGetter: View {
    @Binding var rect: CGRect

    var body: some View {
        GeometryReader { geometry in
            Group { () -> AnyView in
                DispatchQueue.main.async {
                    self.rect = geometry.frame(in: .global)
                }

                return AnyView(Color.clear)
            }
        }
    }
}

请注意,DispatchQueue.main.async是为了避免在渲染视图时修改视图状态的可能性。

键盘守护者

KeyboardGuardian的目的是跟踪键盘显示/隐藏事件,并计算视图需要移动的空间。

注意,当用户从一个字段切换到另一个字段时,它会刷新幻灯片*

import SwiftUI
import Combine

final class KeyboardGuardian: ObservableObject {
    public var rects: Array<CGRect>
    public var keyboardRect: CGRect = CGRect()

    // keyboardWillShow notification may be posted repeatedly,
    // this flag makes sure we only act once per keyboard appearance
    public var keyboardIsHidden = true

    @Published var slide: CGFloat = 0

    var showField: Int = 0 {
        didSet {
            updateSlide()
        }
    }

    init(textFieldCount: Int) {
        self.rects = Array<CGRect>(repeating: CGRect(), count: textFieldCount)

        NotificationCenter.default.addObserver(self, selector: #selector(keyBoardWillShow(notification:)), name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyBoardDidHide(notification:)), name: UIResponder.keyboardDidHideNotification, object: nil)

    }

    deinit {
        NotificationCenter.default.removeObserver(self)
    }

    @objc func keyBoardWillShow(notification: Notification) {
        if keyboardIsHidden {
            keyboardIsHidden = false
            if let rect = notification.userInfo?["UIKeyboardFrameEndUserInfoKey"] as? CGRect {
                keyboardRect = rect
                updateSlide()
            }
        }
    }

    @objc func keyBoardDidHide(notification: Notification) {
        keyboardIsHidden = true
        updateSlide()
    }

    func updateSlide() {
        if keyboardIsHidden {
            slide = 0
        } else {
            let tfRect = self.rects[self.showField]
            let diff = keyboardRect.minY - tfRect.maxY

            if diff > 0 {
                slide += diff
            } else {
                slide += min(diff, 0)
            }

        }
    }
}

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];
}