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

在textFieldDidBginEditing和textFieldDidEndEditing中调用函数[self-animateTextField:textField up:YES],如下所示:

-(void)textFieldDidBeginEditing:(UITextField *)textField 
{ 
    [self animateTextField:textField up:YES]; 
}

- (void)textFieldDidEndEditing:(UITextField *)textField
{
    [self animateTextField:textField up:NO];
}

-(void)animateTextField:(UITextField*)textField up:(BOOL)up
{
    const int movementDistance = -130; // tweak as needed
    const float movementDuration = 0.3f; // tweak as needed

    int movement = (up ? movementDistance : -movementDistance); 

    [UIView beginAnimations: @"animateTextField" context: nil];
    [UIView setAnimationBeginsFromCurrentState: YES];
    [UIView setAnimationDuration: movementDuration];
    self.view.frame = CGRectOffset(self.view.frame, 0, movement);
    [UIView commitAnimations];
}

我希望这段代码对你有所帮助。

雨燕5

func animateTextField(textField: UITextField, up: Bool) {
    
    let movementDistance: CGFloat = -130
    let movementDuration: Double = 0.3
    
    var movement:CGFloat = 0
    if up {
        movement = movementDistance
    } else {
        movement = -movementDistance
    }
    
    UIView.animate(withDuration: movementDuration, delay: 0, options: [.beginFromCurrentState]) {
        self.view.frame = self.view.frame.offsetBy(dx: 0, dy: movement)
    }
}

func textFieldDidBeginEditing(_ textField: UITextField) {
    animateTextField(textField: textField, up: true)
}

func textFieldDidEndEditing(_ textField: UITextField) {
    animateTextField(textField: textField, up: false)
}

其他回答

我对UIScrollView由多个UITextField组成也有很多问题,其中一个或多个在编辑时会被键盘遮挡。

如果UIScrollView滚动不正确,请考虑以下几点。

1) 确保contentSize大于UIScrollView框架大小。理解UIScrollViews的方法是UIScrollView就像一个查看contentSize中定义的内容的窗口。因此,如果要让UIScrollview滚动到任何位置,contentSize必须大于UIScrollview。否则,不需要滚动,因为contentSize中定义的所有内容都已可见。BTW,默认contentSize=CGSizeZero。

2) 既然您已经了解到UIScrollView实际上是一个“内容”窗口,那么确保键盘不会遮挡UIScroll View的查看“窗口”的方法就是调整UIScrollView的大小,这样当键盘出现时,UIScrollView窗口的大小就等于UIScrollviewframe.size.height减去键盘的高度。这将确保您的窗口仅是那个小的可视区域。

3) 这里有一个陷阱:当我第一次实现这一点时,我想我必须获得编辑文本字段的CGRect,并调用UIScrollView的scrollRecToVisible方法。我通过调用scrollRecToVisible方法实现了UITextFieldDelegate方法textFieldDidBeginEditing。这实际上产生了一个奇怪的副作用,即滚动会将UITextField捕捉到位。在很长一段时间里,我都搞不清那是什么。然后我注释了textFieldDidBegginEditingDelegate方法,这一切都奏效了!!(???). 事实证明,我相信UIScrollView实际上隐式地将当前编辑的UITextField带入可视窗口。我对UITextFieldDelegate方法的实现以及随后对scrollRecToVisible的调用是多余的,这是产生奇怪副作用的原因。

因此,当键盘出现时,以下是在UIScrollView中正确滚动UITextField的步骤。

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.

- (void)viewDidLoad 
{
    [super viewDidLoad];

    // register for keyboard notifications
    [[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector(keyboardWillShow:) 
                                                 name:UIKeyboardWillShowNotification 
                                               object:self.view.window];
    // register for keyboard notifications
    [[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector(keyboardWillHide:) 
                                                 name:UIKeyboardWillHideNotification 
                                               object:self.view.window];
    keyboardIsShown = NO;
    //make contentSize bigger than your scrollSize (you will need to figure out for your own use case)
    CGSize scrollContentSize = CGSizeMake(320, 345);
    self.scrollView.contentSize = scrollContentSize;
}

- (void)keyboardWillHide:(NSNotification *)n
{
    NSDictionary* userInfo = [n userInfo];

    // get the size of the keyboard
    CGSize keyboardSize = [[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;


    // resize the scrollview
    CGRect viewFrame = self.scrollView.frame;
    // I'm also subtracting a constant kTabBarHeight because my UIScrollView was offset by the UITabBar so really only the portion of the keyboard that is leftover pass the UITabBar is obscuring my UIScrollView.
    viewFrame.size.height += (keyboardSize.height - kTabBarHeight);

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationBeginsFromCurrentState:YES];
    [self.scrollView setFrame:viewFrame];
    [UIView commitAnimations];

    keyboardIsShown = NO;
}

- (void)keyboardWillShow:(NSNotification *)n
{
    // This is an ivar I'm using to ensure that we do not do the frame size adjustment on the `UIScrollView` if the keyboard is already shown.  This can happen if the user, after fixing editing a `UITextField`, scrolls the resized `UIScrollView` to another `UITextField` and attempts to edit the next `UITextField`.  If we were to resize the `UIScrollView` again, it would be disastrous.  NOTE: The keyboard notification will fire even when the keyboard is already shown.
    if (keyboardIsShown) {
        return;
    }

    NSDictionary* userInfo = [n userInfo];

    // get the size of the keyboard
    CGSize keyboardSize = [[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;

    // resize the noteView
    CGRect viewFrame = self.scrollView.frame;
    // I'm also subtracting a constant kTabBarHeight because my UIScrollView was offset by the UITabBar so really only the portion of the keyboard that is leftover pass the UITabBar is obscuring my UIScrollView.
    viewFrame.size.height -= (keyboardSize.height - kTabBarHeight);

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationBeginsFromCurrentState:YES];
    [self.scrollView setFrame:viewFrame];
    [UIView commitAnimations];
    keyboardIsShown = YES;
}

在viewDidLoad上注册键盘通知在viewDidUnload中注销键盘nofitions确保contentSize设置为大于UIScrollView at viewDidLoad当有键盘时,缩小UIScrollView当键盘离开时,恢复UIScrollView。使用ivar来检测键盘是否已经显示在屏幕上,因为每次UITextField选项卡时都会发送键盘通知,即使键盘已经存在,以避免在UIScrollView已经缩小时缩小它

需要注意的一点是,当您单击另一个UITextField时,即使键盘已经在屏幕上,UIKeyboardWillShowNotification也会启动。当键盘已经在屏幕上时,我使用ivar来避免调整UIScrollView的大小。当键盘已经存在时,不小心调整UIScrollView的大小将是灾难性的!

希望这段代码能让你们中的一些人省去很多麻烦。

只需将其添加到pod文件->pod“IQKeyboardManager”

这就是它,处理所有的键盘,滚动视图和一切!

你不需要编写任何代码,找不到更好的解决方案!

它有一个扩展,如果有多个文本字段,它可以处理文本字段显示、屏幕移动、下一个和上一个箭头。

它还有一个自定义完成按钮,可以删除。

链接->https://github.com/hackiftekhar/IQKeyboardManager

我不确定将视图上移是否是正确的方法。我用了不同的方式,调整了UIScrollView的大小。我在一篇小文章中详细解释了它。

这里有很多答案,但这很有效,而且比大多数答案都短得多:

- (void)textFieldDidBeginEditing:(UITextField *)sender
{
    UIScrollView *scrollView = (UIScrollView *)self.view; // assuming this method is pasted into the UIScrollView's controller
    const double dontHardcodeTheKeyboardHeight = 162;
    double textY = [sender convertPoint:CGPointMake(0, 0) toView:scrollView].y;
    if (textY - scrollView.contentOffset.y + sender.frame.size.height > self.view.frame.size.height - dontHardcodeTheKeyboardHeight)
        [scrollView setContentOffset:CGPointMake(0.0, textY - 10) animated:YES];
}

-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)
            }

        }
    }
}