使用 iOS SDK:
我有一个带有UITextField
的UIView
, UITextField
一个键盘。我需要它能够:
提起键盘后,允许滚动UIScrollView
的内容以查看其他文本字段
自动 “跳跃”(通过向上滚动)或缩短
我知道我需要一个UIScrollView
。我尝试将UIView
的类更改为UIScrollView
但仍然无法向上或向下滚动文本框。
我是否需要UIView
和UIScrollView
?一个人会进入另一个人吗?
为了自动滚动到活动文本字段,需要实现什么?
理想情况下,将在 Interface Builder 中完成尽可能多的组件设置。我只想编写所需的代码。
注意:我正在使用的UIView
(或UIScrollView
)由一个标签栏( UITabBar
)调出,该UITabBar
需要正常运行。
编辑:我只是在键盘出现时添加滚动条。即使不需要它,我也觉得它提供了一个更好的界面,因为例如,用户可以滚动和更改文本框。
我可以在键盘上下移动时更改UIScrollView
的帧大小的地方工作。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
}
但是,这不会自动 “向上移动” 或将下部文本字段居中显示区域的中心,这是我真正想要的。
如果您现在的内容不适合 iPhone 屏幕,则只需要ScrollView
。 (如果要添加ScrollView
作为组件的超级视图。只是为了在键盘出现时使TextField
向上滚动,则不需要这样做。)
为了在不被键盘隐藏的情况下显示textfields
,标准方法是在显示键盘时上下移动具有文本字段的视图。
这是一些示例代码:
#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];
}
对于由多个UITextFields
组成的UIScrollView
,我也遇到很多问题,其中的一个或多个在编辑时会被键盘遮盖。
如果您的UIScrollView
滚动不正确,则需要考虑以下事项。
1)确保您的 contentSize 大于UIScrollView
框架的大小。理解UIScrollViews
的方法是UIScrollView
就像 contentSize 中定义的内容的查看窗口。因此,当UIScrollview
滚动到任何位置时,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经可见。顺便说一句,默认 contentSize = CGSizeZero
。
2)现在您已经知道UIScrollView
确实是进入 “内容” 的窗口,确保键盘不会遮挡UIScrollView's
查看 “窗口” 的方法是调整UIScrollView
大小,以便在存在键盘时,将UIScrollView
窗口的大小调整为仅原始UIScrollView
frame.size.height 减去键盘的高度。这将确保您的窗口仅是一个较小的可见区域。
3)这就是要注意的问题:第一次实现此功能时,我认为我必须获取已编辑文本字段的CGRect
并调用UIScrollView's
scrollRecToVisible 方法。我通过调用scrollRecToVisible
方法实现了UITextFieldDelegate
方法textFieldDidBeginEditing
。这实际上与一个奇怪的副作用是滚动将其卡工作UITextField
到位。在最长的时间内,我不知道那是什么。然后我注释掉了textFieldDidBeginEditing
Delegate 方法,并且一切正常!(???)。事实证明,我相信UIScrollView
实际上隐式地将当前编辑的UITextField
隐式UITextField
入可见窗口。我对UITextFieldDelegate
方法的实现以及随后对scrollRecToVisible
调用是多余的,并且是造成奇怪副作用的原因。
因此,这是在键盘出现时正确滚动UIScrollView
的UITextField
到位的步骤。
// 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;
}
viewDidLoad
注册键盘通知viewDidUnload
取消注册键盘键盘contentSize
并大于viewDidLoad
的UIScrollView
UIScrollView
UIScrollView
。 UITextField
的标签即使键盘已经存在,以避免萎缩 UIScrollView
时,它已经缩水 要注意的一件事是,即使您在另一个UITextField
上进行选项卡UIKeyboardWillShowNotification
时,即使键盘已经在屏幕上, UIKeyboardWillShowNotification
也会触发。我通过使用 ivar 避免在键盘已经在屏幕上时调整UIScrollView
大小来解决此问题。当键盘已经存在时,无意中调整UIScrollView
大小将是灾难性的!
希望这段代码可以使您省去很多麻烦。
实际上最好使用docs 中提供的 Apple 的实现。但是,他们提供的代码是错误的。替换在keyboardWasShown:
找到的部分keyboardWasShown:
在以下注释的正下方:
NSDictionary* info = [aNotification userInfo];
CGRect keyPadFrame=[[UIApplication sharedApplication].keyWindow convertRect:[[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue] fromView:self.view];
CGSize kbSize =keyPadFrame.size;
CGRect activeRect=[self.view convertRect:activeField.frame fromView:activeField.superview];
CGRect aRect = self.view.bounds;
aRect.size.height -= (kbSize.height);
CGPoint origin = activeRect.origin;
origin.y -= backScrollView.contentOffset.y;
if (!CGRectContainsPoint(aRect, origin)) {
CGPoint scrollPoint = CGPointMake(0.0,CGRectGetMaxY(activeRect)-(aRect.size.height));
[backScrollView setContentOffset:scrollPoint animated:YES];
}
Apple 的代码存在以下问题:(1)它们始终计算该点是否在视图的框架内,但是它是ScrollView
,因此它可能已经滚动了,您需要考虑该偏移量:
origin.y -= scrollView.contentOffset.y
(2)他们将 contentOffset 按键盘的高度移动,但我们想要相反的操作(我们希望将contentOffset
按屏幕上可见的高度移动,而不是不可见的高度):
activeField.frame.origin.y-(aRect.size.height)
在textFieldDidBeginEditting
和textFieldDidEndEditing
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];
}
希望这段代码对您有所帮助。
在 Swift 2
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.beginAnimations("animateTextField", context: nil)
UIView.setAnimationBeginsFromCurrentState(true)
UIView.setAnimationDuration(movementDuration)
self.view.frame = CGRectOffset(self.view.frame, 0, movement)
UIView.commitAnimations()
}
func textFieldDidBeginEditing(textField: UITextField)
{
self.animateTextField(textField, up:true)
}
func textFieldDidEndEditing(textField: UITextField)
{
self.animateTextField(textField, up:false)
}
SWIFT 3
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.beginAnimations("animateTextField", context: nil)
UIView.setAnimationBeginsFromCurrentState(true)
UIView.setAnimationDuration(movementDuration)
self.view.frame = self.view.frame.offsetBy(dx: 0, dy: movement)
UIView.commitAnimations()
}
func textFieldDidBeginEditing(textField: UITextField)
{
self.animateTextField(textField: textField, up:true)
}
func textFieldDidEndEditing(textField: UITextField)
{
self.animateTextField(textField: textField, up:false)
}
仅使用 TextFields:
1a)使用Interface Builder
:选择所有 TextFields => Edit => Embed In => ScrollView
1b)在称为 scrollView 的 UIScrollView 中手动嵌入 TextField
2)设置UITextFieldDelegate
3)设置每个textField.delegate = self;
(或在Interface Builder
建立连接)
4) 复制 / 粘贴:
- (void)textFieldDidBeginEditing:(UITextField *)textField {
CGPoint scrollPoint = CGPointMake(0, textField.frame.origin.y);
[scrollView setContentOffset:scrollPoint animated:YES];
}
- (void)textFieldDidEndEditing:(UITextField *)textField {
[scrollView setContentOffset:CGPointZero animated:YES];
}
对于通用解决方案 ,这是我实现IQKeyboardManager 的方法 。
步骤 1:-我在单例类中添加了UITextField
, UITextView
和UIKeyboard
全局通知。我称它为IQKeyboardManager 。
步骤 2:-如果找到UIKeyboardWillShowNotification
, UITextFieldTextDidBeginEditingNotification
或UITextViewTextDidBeginEditingNotification
通知,我尝试从UIWindow.rootViewController
层次结构中获取topMostViewController
实例。为了正确地发现UITextField
/ UITextView
,需要调整topMostViewController.view
的框架。
步骤 3:-我相对于第一个响应的UITextField
/ UITextView
计算了topMostViewController.view
预期移动距离。
步骤 4:-我根据预期的移动距离上下移动了topMostViewController.view.frame
。
步骤 5:-如果找到UIKeyboardWillHideNotification
, UITextFieldTextDidEndEditingNotification
或UITextViewTextDidEndEditingNotification
通知,则我再次尝试从UIWindow.rootViewController
层次结构中获取topMostViewController
实例。
步骤 6:-我计算了topMostViewController.view
受干扰距离,该距离需要恢复到其原始位置。
步骤 7:-我根据受干扰的距离恢复了topMostViewController.view.frame
。
步骤 8:-我在应用程序加载时实例化了单例IQKeyboardManager类实例,因此应用程序中的每个UITextField
/ UITextView
都会根据预期的移动距离自动进行调整。
这就是IQKeyboardManager 真正为您完成的所有工作,而无需任何代码 !只需要将相关的源文件拖放到项目中即可。 IQKeyboardManager还支持 “ 设备方向” ,“ 自动 UIToolbar 管理” ,“ KeybkeyboardDistanceFromTextField”等功能。
我整理了一个通用的UIScrollView
, UITableView
甚至UICollectionView
子类,该子类负责将其中的所有文本字段移出键盘。
当键盘即将出现时,子类将找到要编辑的子视图,并调整其框架和内容偏移量以确保该视图可见,并带有动画以匹配键盘弹出窗口。键盘消失后,它将恢复其先前的大小。
它基本上可以与任何设置一起使用,既可以是基于UITableView
的界面,也可以是由手动放置的视图组成的界面。
这是 tis: 用于将文本字段移出键盘的解决方案
对于Swift程序员:
这将为您完成所有工作,只需将它们放在视图控制器类中,并将UITextFieldDelegate
实现到视图控制器,并将 textField 的委托设置为self
textField.delegate = self // Setting delegate of your UITextField to self
实现委托回调方法:
func textFieldDidBeginEditing(textField: UITextField) {
animateViewMoving(true, moveValue: 100)
}
func textFieldDidEndEditing(textField: UITextField) {
animateViewMoving(false, moveValue: 100)
}
// Lifting the view up
func animateViewMoving (up:Bool, moveValue :CGFloat){
let movementDuration:NSTimeInterval = 0.3
let movement:CGFloat = ( up ? -moveValue : moveValue)
UIView.beginAnimations( "animateView", context: nil)
UIView.setAnimationBeginsFromCurrentState(true)
UIView.setAnimationDuration(movementDuration )
self.view.frame = CGRectOffset(self.view.frame, 0, movement)
UIView.commitAnimations()
}
对于 Swift 4,4.2,5:更改
self.view.frame = CGRectOffset(self.view.frame, 0, movement)
至
self.view.frame = self.view.frame.offsetBy(dx: 0, dy: movement)
关于此实现的最后一点说明:如果在显示键盘时将另一个视图控制器推到堆栈上,则会产生一个错误,即视图返回到其中心框架,但键盘偏移未重置。例如,您的键盘是 nameField 的第一个响应者,但是随后您按下了一个按钮,该按钮会将您的 Help View Controller 推入堆栈。要解决偏移量错误,请确保在离开视图控制器之前调用 nameField.resignFirstResponder(),并确保同时调用了 textFieldDidEndEditing 委托方法。我在 viewWillDisappear 方法中执行此操作。
已经有很多答案,但是上面的解决方案仍然没有一个具有 “完美” 的无错误,向后兼容和无闪烁动画所需的所有花哨的定位内容。 (在同时对帧 / 边界和 contentOffset 进行动画处理,不同的界面方向,iPad 拆分键盘等时发生错误)
让我分享我的解决方案:
(假设您已设置UIKeyboardWill(Show|Hide)Notification
)
// Called when UIKeyboardWillShowNotification is sent
- (void)keyboardWillShow:(NSNotification*)notification
{
// if we have no view or are not visible in any window, we don't care
if (!self.isViewLoaded || !self.view.window) {
return;
}
NSDictionary *userInfo = [notification userInfo];
CGRect keyboardFrameInWindow;
[[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] getValue:&keyboardFrameInWindow];
// the keyboard frame is specified in window-level coordinates. this calculates the frame as if it were a subview of our view, making it a sibling of the scroll view
CGRect keyboardFrameInView = [self.view convertRect:keyboardFrameInWindow fromView:nil];
CGRect scrollViewKeyboardIntersection = CGRectIntersection(_scrollView.frame, keyboardFrameInView);
UIEdgeInsets newContentInsets = UIEdgeInsetsMake(0, 0, scrollViewKeyboardIntersection.size.height, 0);
// this is an old animation method, but the only one that retains compaitiblity between parameters (duration, curve) and the values contained in the userInfo-Dictionary.
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
[UIView setAnimationCurve:[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
_scrollView.contentInset = newContentInsets;
_scrollView.scrollIndicatorInsets = newContentInsets;
/*
* Depending on visual layout, _focusedControl should either be the input field (UITextField,..) or another element
* that should be visible, e.g. a purchase button below an amount text field
* it makes sense to set _focusedControl in delegates like -textFieldShouldBeginEditing: if you have multiple input fields
*/
if (_focusedControl) {
CGRect controlFrameInScrollView = [_scrollView convertRect:_focusedControl.bounds fromView:_focusedControl]; // if the control is a deep in the hierarchy below the scroll view, this will calculate the frame as if it were a direct subview
controlFrameInScrollView = CGRectInset(controlFrameInScrollView, 0, -10); // replace 10 with any nice visual offset between control and keyboard or control and top of the scroll view.
CGFloat controlVisualOffsetToTopOfScrollview = controlFrameInScrollView.origin.y - _scrollView.contentOffset.y;
CGFloat controlVisualBottom = controlVisualOffsetToTopOfScrollview + controlFrameInScrollView.size.height;
// this is the visible part of the scroll view that is not hidden by the keyboard
CGFloat scrollViewVisibleHeight = _scrollView.frame.size.height - scrollViewKeyboardIntersection.size.height;
if (controlVisualBottom > scrollViewVisibleHeight) { // check if the keyboard will hide the control in question
// scroll up until the control is in place
CGPoint newContentOffset = _scrollView.contentOffset;
newContentOffset.y += (controlVisualBottom - scrollViewVisibleHeight);
// make sure we don't set an impossible offset caused by the "nice visual offset"
// if a control is at the bottom of the scroll view, it will end up just above the keyboard to eliminate scrolling inconsistencies
newContentOffset.y = MIN(newContentOffset.y, _scrollView.contentSize.height - scrollViewVisibleHeight);
[_scrollView setContentOffset:newContentOffset animated:NO]; // animated:NO because we have created our own animation context around this code
} else if (controlFrameInScrollView.origin.y < _scrollView.contentOffset.y) {
// if the control is not fully visible, make it so (useful if the user taps on a partially visible input field
CGPoint newContentOffset = _scrollView.contentOffset;
newContentOffset.y = controlFrameInScrollView.origin.y;
[_scrollView setContentOffset:newContentOffset animated:NO]; // animated:NO because we have created our own animation context around this code
}
}
[UIView commitAnimations];
}
// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillHide:(NSNotification*)notification
{
// if we have no view or are not visible in any window, we don't care
if (!self.isViewLoaded || !self.view.window) {
return;
}
NSDictionary *userInfo = notification.userInfo;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:[[userInfo valueForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
[UIView setAnimationCurve:[[userInfo valueForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
// undo all that keyboardWillShow-magic
// the scroll view will adjust its contentOffset apropriately
_scrollView.contentInset = UIEdgeInsetsZero;
_scrollView.scrollIndicatorInsets = UIEdgeInsetsZero;
[UIView commitAnimations];
}
Shiun 表示:“事实证明,我相信 UIScrollView 实际上隐式地将当前编辑的 UITextField 隐式地带到可见窗口中”,这对于 iOS 3.1.3 似乎是正确的,但对于 3.2、4.0 或 4.1 则不成立。我必须添加一个显式的 scrollRectToVisible,以使 UITextField 在 iOS> = 3.2 上可见。