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

Shiun表示:“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。”这似乎适用于iOS 3.1.3,但不适用于3.2、4.0或4.1。为了使UITextField在iOS上可见,我必须添加一个显式的scrollRectToVisible。

其他回答

如果您现在的内容不适合iPhone屏幕,您只需要一个ScrollView。(如果您添加ScrollView作为组件的超级视图,只是为了在键盘启动时使TextField向上滚动,那么就不需要了。)防止TextFields被键盘覆盖的标准方法是在显示键盘时向上/向下移动视图。

下面是一些示例代码:

#define kOFFSET_FOR_KEYBOARD 80.0

-(void)keyboardWillShow {
    // Animate the current view out of the way
    if (self.view.frame.origin.y >= 0)
    {
        [self setViewMovedUp:YES];
    }
    else if (self.view.frame.origin.y < 0)
    {
        [self setViewMovedUp:NO];
    }
}

-(void)keyboardWillHide {
    if (self.view.frame.origin.y >= 0)
    {
        [self setViewMovedUp:YES];
    }
    else if (self.view.frame.origin.y < 0)
    {
        [self setViewMovedUp:NO];
    }
}

-(void)textFieldDidBeginEditing:(UITextField *)sender
{
    if ([sender isEqual:mailTf])
    {
        //move the main view, so that the keyboard does not hide it.
        if  (self.view.frame.origin.y >= 0)
        {
            [self setViewMovedUp:YES];
        }
    }
}

//method to move the view up/down whenever the keyboard is shown/dismissed
-(void)setViewMovedUp:(BOOL)movedUp
{
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3]; // if you want to slide up the view

    CGRect rect = self.view.frame;
    if (movedUp)
    {
        // 1. move the view's origin up so that the text field that will be hidden come above the keyboard 
        // 2. increase the size of the view so that the area behind the keyboard is covered up.
        rect.origin.y -= kOFFSET_FOR_KEYBOARD;
        rect.size.height += kOFFSET_FOR_KEYBOARD;
    }
    else
    {
        // revert back to the normal state.
        rect.origin.y += kOFFSET_FOR_KEYBOARD;
        rect.size.height -= kOFFSET_FOR_KEYBOARD;
    }
    self.view.frame = rect;

    [UIView commitAnimations];
}


- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    // register for keyboard notifications
    [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillShow)
                                             name:UIKeyboardWillShowNotification
                                           object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillHide)
                                             name:UIKeyboardWillHideNotification
                                           object:nil];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    // unregister for keyboard notifications while not visible.
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                             name:UIKeyboardWillShowNotification
                                           object:nil];

    [[NSNotificationCenter defaultCenter] removeObserver:self
                                             name:UIKeyboardWillHideNotification
                                           object:nil];
}

它很简单:-

在TextFieldDidBegginEditing中:-

self.view.frame=CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y-150, self.view.frame.size.width, self.view.frame.size.height);

在TextFieldShouldEndEditing中:-

self.view.frame=CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y+150, self.view.frame.size.width, self.view.frame.size.height);

这将非常有效。滚动视图可以根据文本字段位置自动调整。我相信你会感觉很好

static const CGFloat KEYBOARD_ANIMATION_DURATION = 0.25;
static const CGFloat MINIMUM_SCROLL_FRACTION = 0.2;
static const CGFloat MAXIMUM_SCROLL_FRACTION = 0.8;
static const CGFloat PORTRAIT_KEYBOARD_HEIGHT = 216;
static const CGFloat LANDSCAPE_KEYBOARD_HEIGHT = 162;
@interface LoginVC ()
{
  CGFloat animatedDistance;
   CGRect viewFrameKey;
}

 //In ViewDidLoad
   viewFrameKey=self.view.frame;



- (void)textFieldDidBeginEditing:(UITextField *)textField
{
CGRect textFieldRect =
[self.view.window convertRect:textField.bounds fromView:textField];
CGRect viewRect =
[self.view.window convertRect:self.view.bounds fromView:self.view];
CGFloat midline = textFieldRect.origin.y + 0.5 * textFieldRect.size.height;
CGFloat numerator =
midline - viewRect.origin.y
- MINIMUM_SCROLL_FRACTION * viewRect.size.height;
CGFloat denominator =
(MAXIMUM_SCROLL_FRACTION - MINIMUM_SCROLL_FRACTION)
* viewRect.size.height;
CGFloat heightFraction = numerator / denominator;
if (heightFraction < 0.0)
{
    heightFraction = 0.0;
}
else if (heightFraction > 1.0)
{
    heightFraction = 1.0;
}
UIInterfaceOrientation orientation =
[[UIApplication sharedApplication] statusBarOrientation];
if (orientation == UIInterfaceOrientationPortrait ||
    orientation == UIInterfaceOrientationPortraitUpsideDown)
{
    animatedDistance = floor(PORTRAIT_KEYBOARD_HEIGHT * heightFraction);
}
else
{
    animatedDistance = floor(LANDSCAPE_KEYBOARD_HEIGHT * heightFraction);
}
CGRect viewFrame = self.view.frame;
viewFrame.origin.y -= animatedDistance;

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];

[self.view setFrame:viewFrame];

[UIView commitAnimations];
}

- (void)textFieldDidEndEditing:(UITextField *)textField
{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];
[self.view setFrame:viewFrameKey];
[UIView commitAnimations];
}

Swift 3.0版本的苹果键盘管理代码如下:以下代码中使用的FloatingTF是iOS中基于材质设计的文本字段。

import UIKit
class SignupViewController: UIViewController, UITextFieldDelegate {

    //MARK: - IBOutlet:
@IBOutlet weak var emailTF: FloatingTF!
@IBOutlet weak var passwordTF: FloatingTF!
@IBOutlet weak var dobTF: FloatingTF!

@IBOutlet weak var scrollView: UIScrollView!

//MARK: - Variable:
var activeTextField: UITextField!

//MARK: - ViewController Lifecycle:
override func viewDidLoad() {
    super.viewDidLoad()        
    emailTF.delegate = self
    passwordTF.delegate = self
    dobTF.delegate = self 
}
override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    registerKeyboardNotifications()
}
override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)

   deRegisterKeyboardNotifications()
}

//MARK: - Keyboard notification observer Methods
fileprivate func registerKeyboardNotifications() {
    NotificationCenter.default.addObserver(self, selector: #selector(SignupViewController.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(SignupViewController.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
fileprivate func deRegisterKeyboardNotifications() {
    NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow, object: self.view.window)
    NotificationCenter.default.removeObserver(self, name: .UIKeyboardDidHide, object: self.view.window)
}
func keyboardWillShow(notification: NSNotification) {

    let info: NSDictionary = notification.userInfo! as NSDictionary
    let value: NSValue = info.value(forKey: UIKeyboardFrameBeginUserInfoKey) as! NSValue
    let keyboardSize: CGSize = value.cgRectValue.size
    let contentInsets: UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize.height, 0.0)
    scrollView.contentInset = contentInsets
    scrollView.scrollIndicatorInsets = contentInsets

    // If active text field is hidden by keyboard, scroll it so it's visible
    // Your app might not need or want this behavior.
    var aRect: CGRect = self.view.frame
    aRect.size.height -= keyboardSize.height
    let activeTextFieldRect: CGRect? = activeTextField?.frame
    let activeTextFieldOrigin: CGPoint? = activeTextFieldRect?.origin
    if (!aRect.contains(activeTextFieldOrigin!)) {
        scrollView.scrollRectToVisible(activeTextFieldRect!, animated:true)
    }    }

func keyboardWillHide(notification: NSNotification) {
    let contentInsets: UIEdgeInsets = .zero
    scrollView.contentInset = contentInsets
    scrollView.scrollIndicatorInsets = contentInsets
}

//MARK: - UITextField Delegate Methods
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    if textField == emailTF {
        passwordTF.becomeFirstResponder()
    }
    else if textField == passwordTF {
        dobTF.becomeFirstResponder()
    }
    else {
        self.view.endEditing(true)
    }
    return true
}

func textFieldDidBeginEditing(_ textField: UITextField) {
    activeTextField = textField
    scrollView.isScrollEnabled = true
}

func textFieldDidEndEditing(_ textField: UITextField) {
    activeTextField = nil
    scrollView.isScrollEnabled = false
}
}

如果文本字段应该位于屏幕底部,那么最神奇的解决方案是在视图控制器上覆盖以下内容:

override var inputAccessoryView: UIView? {
    return <yourTextField>
}