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

首先,我为您的页面推荐一个更好的设计,这样就不需要滚动视图。如果您有许多文本字段,您仍然不必使用ScrollView,这只会使事情变得复杂。您只需在控制器原始视图的顶部添加一个容器UIView,然后将这些文本字段放在该视图上。当键盘显示或消失时,只需使用动画移动此容器视图。

其他回答

我想延长@sumanthkodi的回答。

正如一些人所说,他的方法在较新的实现中不起作用,因为当您使用约束时,UIView无法移动。

我编辑了如下代码(并移植到Swift 2.0),希望它能帮助一些人:


1) 参照要向上移动的视图的垂直约束:

@IBOutlet var viewConstraint: NSLayoutConstraint!

确保在脚本中使用约束引用此变量。

2) 添加委托并实现侦听器。这是与之前相同的实现:

class YourViewController: UIViewController, UITextFieldDelegate {

    ...

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

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

    ...

}

3) 将动画方法animateTextField添加到YourViewController类。根据需要设置临时约束值。

func animateTextField(textfield: UITextField, up: Bool) {

    let originalConstraint = 50
    let temporaryConstraint = 0
    let movementDuration = 0.3

    let constraint = CGFloat(up ? temporaryConstraint : originalConstraint)

    containerViewConstraint.constant = constraint
    UIView.animateWithDuration(movementDuration) {
        self.view.layoutIfNeeded()
    }

}

您需要以编程方式添加具有特定帧大小的滚动视图。您必须在.h文件中添加UIScrollViewDelegate。您必须启用滚动视图,以便在viewDidLoad()中编写以下内容。

scrollview.scrollEnabled=YES;
scrollview.delegate=self;

scrollview.frame = CGRectMake(x,y,width,height);
//---set the content size of the scroll view--- 

[scrollview setContentSize:CGSizeMake(height,width)];

这样,可以添加x、y、宽度和高度值。

尝试IQKeyboard库。

这将自动向上移动文本字段。

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:

请在文本字段委派方法中添加这些行,以便在iPad中向上滚动。

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

    CGPoint pt;
    CGRect rc = [textField bounds];
    rc = [textField convertRect:rc toView:scrlView];
    pt = rc.origin;
    pt.x = 0;
    pt.y -= 100;

    [scrlView setContentOffset:pt animated:YES];

    scrlView.contentSize = CGSizeMake(scrlView.frame.size.width, button.frame.origin.y+button.frame.size.height + 8 + 370);
}