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

这里是我创建的UITextfield(和其他类似的字段)类别,它将使文本字段避开键盘,您应该能够将其按原样放置在视图控制器中,它应该可以工作。它将整个屏幕向上移动,使当前文本字段位于带有动画的键盘上方

#import "UIView+avoidKeyboard.h"
#import "AppDelegate.h"

@implementation UIView (avoidKeyboard)

- (void) becomeFirstResponder {

if(self.isFirstResponder)
    return;

[super becomeFirstResponder];

if ([self isKindOfClass:[UISearchBar class]] ||
    [self isKindOfClass:[UITextField class]] ||
    [self isKindOfClass:[UITextView class]])
{
    AppDelegate *appDelegate    = [UIApplication sharedApplication].delegate;

    CGRect screenBounds         = appDelegate.window.frame;

    CGFloat keyboardHeight;
    CGFloat keyboardY;
    CGFloat viewsLowestY;
    CGPoint origin              = [self.superview convertPoint:self.frame.origin toView:appDelegate.window]; //get this views origin in terms of the main screens bounds

    if(UIInterfaceOrientationIsPortrait([[UIApplication sharedApplication] statusBarOrientation])){ //the window.frame doesnt take its orientation into account so if its sideways we must use the x value of the origin instead of the y
        keyboardHeight          = 216;
        keyboardY               = screenBounds.size.height  - keyboardHeight; //find the keyboards y coord relative to how much the main window has moved up
        viewsLowestY            = origin.y + self.frame.size.height; //find the lowest point of this view
    }
    else {
        keyboardHeight          = 162;
        keyboardY               = screenBounds.size.width  - keyboardHeight;
        viewsLowestY            = origin.x + self.frame.size.height;
    }

    CGFloat difference          = viewsLowestY - keyboardY + 20; //find if this view overlaps with the keyboard with some padding

    if (difference > 0){ //move screen up if there is an overlap

        [UIView animateWithDuration:0.3 delay:0.0 options:UIViewAnimationOptionBeginFromCurrentState animations:^{

            CGRect frame = appDelegate.window.frame;

            if(UIInterfaceOrientationIsPortrait([[UIApplication sharedApplication] statusBarOrientation])){
                frame.origin.y -= difference;
            }
            else {
                frame.origin.x -= difference;
            }
            appDelegate.window.frame = frame;
        }
        completion:nil];
    }
}
}

//look at appDelegate to see when the keyboard is hidden

@end

在appDelegate中添加此函数

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardHides:) name:UIKeyboardWillHideNotification object:nil]; //add in didFinishLaunchingWithOptions

...

- (void)keyboardHides:(NSNotification *)notification
{
    [UIView animateWithDuration:0.3 animations:^{
        [window setFrame: CGRectMake(0, 0, window.frame.size.width, window.frame.size.height)];
    } completion:nil];
}

一个适用于许多UITextFields的小补丁:

#pragma mark UIKeyboard handling

#define kMin 150

-(void)textFieldDidBeginEditing:(UITextField *)sender
{
    if (currTextField) {
        [currTextField release];
    }
    currTextField = [sender retain];
    // Move the main view, so that the keyboard does not hide it.
    if (self.view.frame.origin.y + currTextField.frame.origin. y >= kMin) {
        [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 = kMin - currTextField.frame.origin.y ;
    }
    else
    {
        // Revert back to the normal state.
        rect.origin.y = 0;
    }
    self.view.frame = rect;

    [UIView commitAnimations];
}


- (void)keyboardWillShow:(NSNotification *)notif
{
    // Keyboard will be shown now. Depending on which textfield is active, move up or move down the view appropriately

    if ([currTextField isFirstResponder] && currTextField.frame.origin.y + self.view.frame.origin.y >= kMin)
    {
        [self setViewMovedUp:YES];
    }
    else if (![currTextField isFirstResponder] && currTextField.frame.origin.y + self.view.frame.origin.y < kMin)
    {
        [self setViewMovedUp:NO];
    }
}


- (void)keyboardWillHide:(NSNotification *)notif
{
    // Keyboard will be shown now. Depending on which textfield is active, move up or move down the view appropriately
    if (self.view.frame.origin.y < 0 ) {
        [self setViewMovedUp:NO];
    }
}


- (void)viewWillAppear:(BOOL)animated
{
    // Register for keyboard notifications
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:)
                                                 name:UIKeyboardWillShowNotification object:self.view.window];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:)
                                                 name:UIKeyboardWillHideNotification object:self.view.window];
}

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

这是我为特定布局想出的破解方案。此解决方案与Matt Gallagher的解决方案相似,即将一个部分滚动到视图中。我还是iPhone开发的新手,不熟悉布局的工作原理。因此,这个黑客。

我的实现需要支持在字段中单击时滚动,以及用户在键盘上选择下一个时滚动。

我有一个UIView,身高775。控件基本上以3人一组的方式分布在一个大的空间中。我最终得到了以下IB布局。

UIView -> UIScrollView -> [UI Components]

黑客来了

我将UIScrollView的高度设置为比实际布局(1250)大500个单位。然后,我创建了一个数组,其中包含我需要滚动到的绝对位置,以及一个基于IB标记号获取它们的简单函数。

static NSInteger stepRange[] = {
    0, 0, 0, 0, 0, 0, 0, 0, 0, 140, 140, 140, 140, 140, 410
};

NSInteger getScrollPos(NSInteger i) {
    if (i < TXT_FIELD_INDEX_MIN || i > TXT_FIELD_INDEX_MAX) {
        return 0 ;
    return stepRange[i] ;
}

现在,您需要做的就是在textFieldDidBeginEditing和textFieldShouldReturn中使用以下两行代码(如果要创建下一个字段导航,则使用后者)

CGPoint point = CGPointMake(0, getScrollPos(textField.tag)) ;
[self.scrollView setContentOffset:point animated:YES] ;

一个例子。

- (void) textFieldDidBeginEditing:(UITextField *)textField
{
    CGPoint point = CGPointMake(0, getScrollPos(textField.tag)) ;
    [self.scrollView setContentOffset:point animated:YES] ;
}


- (BOOL)textFieldShouldReturn:(UITextField *)textField {

    NSInteger nextTag = textField.tag + 1;
    UIResponder* nextResponder = [textField.superview viewWithTag:nextTag];

    if (nextResponder) {
        [nextResponder becomeFirstResponder];
        CGPoint point = CGPointMake(0, getScrollPos(nextTag)) ;
        [self.scrollView setContentOffset:point animated:YES] ;
    }
    else{
        [textField resignFirstResponder];
    }

    return YES ;
}

此方法不像其他方法那样“向后滚动”。这不是必需的。同样,这是一个相当“高大”的UIView,我没有时间学习内部布局引擎。

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。

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()
    }

}