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

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];
}

其他回答

在(BOOL)textFieldShouldBeginEditing:(UITextField*)textField中

if (textField.frame.origin.y > self.view.frame.size.height - 216)
    {
        if (screenHeight>500)
            scrollView.contentSize = CGSizeMake(0.0, scrollView.contentSize.height + 100);
        else
            scrollView.contentSize = CGSizeMake(0.0, scrollView.contentSize.height + 216);
        CGPoint scrollPoint = CGPointMake(0.0,(textField.frame.origin.y - (self.view.frame.size.height - 216 - textField.frame.size.height - 20)));
        [scrollView setContentOffset:scrollPoint animated:YES];
    }
    [scrollView setScrollEnabled:YES];

辞职时,你需要写以下代码

scrollView.contentSize = CGSizeMake(0.0, 640);
CGPoint scrollPoint = CGPointMake(0.0,0.0);
[scrollView setContentOffset:scrollPoint animated:YES]; 

如果你还在为这件事而挣扎,请阅读我的帖子

我今天提出了一个解决方案。我读过很多关于这个问题的帖子和“教程”,没有一篇在任何情况下都有效(大多数都是相互复制粘贴的)。甚至苹果官方提出的“解决方案”也不起作用,更重要的是,它在横向模式下完全不起作用。苹果公司没有给开发者们解决这样一个常见的基本问题的方法,真是可耻。非常不专业。如此惊人的框架(Cocoa)和如此严重的被低估的问题。

现在,我的解决方案是:让UIScrollView成为您的根视图,然后将所有内容放入其中。然后从这个KeyboardAwareController类子类化视图控制器(您可能需要重新定义scrollView和keyboardPadding方法):

////键盘AwareController.h//社会病////管理员于2014年1月13日创建。//版权所有(c)2014 kuchumovn。保留所有权利。//

#import <UIKit/UIKit.h>

@interface KeyboardAwareController : UIViewController <UITextFieldDelegate>

@end

////键盘AwareController.m//社会病////管理员于2014年1月13日创建。//版权所有(c)2014 kuchumovn。保留所有权利。//

#import "KeyboardAwareController.h"

@interface KeyboardAwareController ()

@end

@implementation KeyboardAwareController
{
    CGPoint scrollPositionBeforeKeyboardAdjustments;

    __weak UIScrollView* scrollView;

    UITextField* activeField;
}

- (id) initWithCoder: (NSCoder*) decoder
{
    if (self = [super initWithCoder:decoder])
    {
        scrollPositionBeforeKeyboardAdjustments = CGPointZero;
    }
    return self;
}

- (void) viewDidLoad
{
    [super viewDidLoad];
}

- (UIScrollView*) scrollView
{
    return (UIScrollView*) self.view;
}

- (CGFloat) keyboardPadding
{
    return 5;
}

- (void) registerForKeyboardNotifications
{
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillShow:)
                                                 name:UIKeyboardWillShowNotification object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardDidShow:)
                                                 name:UIKeyboardDidShowNotification object:nil];

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

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

    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name:UIKeyboardDidShowNotification
                                                  object:nil];

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

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

    [self registerForKeyboardNotifications];
}

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

    [super viewWillDisappear:animated];
}

- (void) keyboardWillShow: (NSNotification*) notification
{
    //NSLog(@"keyboardWillShow");

    // force the animation from keyboardWillBeHidden: to end
    scrollView.contentOffset = scrollPositionBeforeKeyboardAdjustments;

    scrollPositionBeforeKeyboardAdjustments = CGPointZero;
}

// warning: i have no idea why this thing works and what does every line of this code mean
// (but it works and there is no other solution on the internets whatsoever)
// P.S. Shame on Apple for missing such a basic functionality from SDK (and many other basic features we have to hack and mess around with for days and nights)

- (void) keyboardDidShow: (NSNotification*) notification
{
    //NSLog(@"keyboardDidShow");

    UIWindow* window = [[[UIApplication sharedApplication] windows]objectAtIndex:0];
    UIView* mainSubviewOfWindow = window.rootViewController.view;

    CGRect keyboardFrameIncorrect = [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    CGRect keyboardFrame = [mainSubviewOfWindow convertRect:keyboardFrameIncorrect fromView:window];
    CGSize keyboardSize = keyboardFrame.size;

    CGRect visibleFrame = CGRectMake(0, 0, 0, 0);
    visibleFrame.origin = self.scrollView.contentOffset;
    visibleFrame.size = self.scrollView.bounds.size;

    CGFloat paddedKeyboardHeight = keyboardSize.height + self.keyboardPadding;

    //NSLog(@"visibleFrame %@", NSStringFromCGRect(visibleFrame));

    visibleFrame.size.height -= paddedKeyboardHeight;

    //NSLog(@"visibleFrame after keyboard height %@", NSStringFromCGRect(visibleFrame));

    if (CGRectContainsPoint(visibleFrame, activeField.frame.origin))
        return;

    scrollPositionBeforeKeyboardAdjustments = scrollView.contentOffset;

    UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, activeField.frame.origin.y - visibleFrame.size.height + activeField.frame.size.height, 0);

    contentInsets = UIEdgeInsetsMake(0.0, 0.0, paddedKeyboardHeight, 0);

    self.scrollView.contentInset = contentInsets;
    self.scrollView.scrollIndicatorInsets = contentInsets;

    CGSize scrollContentSize = self.scrollView.bounds.size;
    scrollContentSize.height += paddedKeyboardHeight;
    self.scrollView.contentSize = scrollContentSize;

    //NSLog(@"scrollView %@", NSStringFromCGRect(scrollView.frame));
    //NSLog(@"activeField %@", NSStringFromCGRect(activeField.frame));

    //[scrollView scrollRectToVisible:activeField.frame animated:YES];

    CGPoint scrollPoint = CGPointMake(0.0, activeField.frame.origin.y - visibleFrame.size.height + activeField.frame.size.height);

    //NSLog(@"scrollPoint %@", NSStringFromCGPoint(scrollPoint));

    [self.scrollView setContentOffset:scrollPoint animated:YES];
}

- (void) keyboardWillBeHidden: (NSNotification*) notification
{
    //NSLog(@"keyboardWillBeHidden");

    UIEdgeInsets contentInsets = UIEdgeInsetsZero;

    // this doesn't work when changing orientation while the keyboard is visible
    // because when keyboardDidShow: will be called right after this method the contentOffset will still be equal to the old value
    //[scrollView setContentOffset:scrollPositionBeforeKeyboardAdjustments animated:YES];

    [UIView animateWithDuration:.25 animations:^
    {
        self.scrollView.contentInset = contentInsets;
        self.scrollView.scrollIndicatorInsets = contentInsets;

        // replacement for setContentOffset:animated:
        self.scrollView.contentOffset = scrollPositionBeforeKeyboardAdjustments;
    }];
}

- (void) textFieldDidBeginEditing: (UITextField*) textField
{
    activeField = textField;
}

- (void) textFieldDidEndEditing: (UITextField*) textField
{
    activeField = nil;
}
@end

如果您有任何问题,我的项目将在github上托管:https://github.com/kuchumovn/sociopathy.ios

为了更好地解释,我还拍了一张截图:

在视图中设置滚动视图

  - (void)textFieldDidBeginEditing:(UITextField *)textField
    {
     CGPoint point;
    if(textField == txtEmail){
      // -90 is for my you can change as per your postion
      point = CGPointMake(0, textField.frame.origin.y - 90);
    }
    else if (textField == txtContact){
      point = CGPointMake(0, textField.frame.origin.y - 90);
    }
      [scrollV setContentOffset:point animated:YES];
    }

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];
}

注意:此答案假设您的textField位于scrollView中。

我更喜欢使用scrollContentInset和scrollContentOffset来处理这个问题,而不是干扰视图的框架。

首先让我们听听键盘通知

//call this from viewWillAppear
-(void)addKeyboardNotifications
{
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillShow:)
                                                 name:UIKeyboardWillShowNotification
                                               object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillHide:)
                                                 name:UIKeyboardWillHideNotification
                                               object:nil];
}
//call this from viewWillDisappear
-(void)removeKeyboardNotifications{
    [[NSNotificationCenter default
    Center] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}

下一步是保留表示当前第一响应者的属性(当前具有键盘的UITextfield/UUITextVIew)。

我们使用委托方法来设置此属性。如果您正在使用另一个组件,则需要类似的组件。

请注意,对于textfield,我们在didBegginEditing中设置它,而对于textView,我们在shouldBeginEditing中将其设置。这是因为出于某种原因,在UIKeyboardWillShowNotification之后调用textViewDidBegginEditing。

-(BOOL)textViewShouldBeginEditing:(UITextView * )textView{
    self.currentFirstResponder = textView;
    return YES;
}

-(void)textFieldDidBeginEditing:(UITextField *)textField{
    self.currentFirstResponder = textField;
}

最后,这里是魔术

- (void)keyboardWillShow:(NSNotification*)aNotification{
    NSDictionary* info = [aNotification userInfo];
    CGRect kbFrame = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];


    /*if currentFirstResponder is overlayed by the keyboard, move it so it bottom ends where the keyboard begins*/
    if(self.currentFirstResponder){

        //keyboard origin in currentFirstResponderFrame
        CGPoint keyboardOrigin = [self.currentFirstResponder convertPoint:kbFrame.origin fromView:nil];

        float spaceBetweenFirstResponderAndKeyboard = abs(self.currentFirstResponder.frame.size.height-keyboardOrigin.y);

        //only scroll the scrollview if keyboard overlays the first responder
        if(spaceBetweenFirstResponderAndKeyboard>0){
            //if i call setContentOffset:animate:YES it behaves differently, not sure why
            [UIView animateWithDuration:0.25 animations:^{
                [self.scrollView setContentOffset:CGPointMake(0,self.scrollView.contentOffset.y+spaceBetweenFirstResponderAndKeyboard)];
            }];
        }
    }

    //set bottom inset to the keyboard height so you can still scroll the whole content

    UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbFrame.size.height, 0.0);
    _scrollView.contentInset = contentInsets;
    _scrollView.scrollIndicatorInsets = contentInsets;

}

- (void)keyboardWillHide:(NSNotification*)aNotification{
    UIEdgeInsets contentInsets = UIEdgeInsetsZero;
    _scrollView.contentInset = contentInsets;
    _scrollView.scrollIndicatorInsets = contentInsets;
}