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

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()
    }

}

这里是一个免费的库,用于iPhone应用程序中的键盘处理键盘处理。你只需要写一行代码:

[AutoScroller addAutoScrollTo:scrollView];

处理表单中的键盘非常棒

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];
}

实际上,最好只使用苹果的实现,正如文档中所提供的那样。然而,他们提供的代码是错误的。将keyboardWasShow:注释下方的部分替换为以下内容:

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];
}

苹果代码存在以下问题:(1) 他们总是计算该点是否在视图的框架内,但它是一个ScrollView,因此它可能已经滚动,您需要考虑该偏移:

origin.y -= scrollView.contentOffset.y

(2) 他们按键盘的高度移动contentOffset,但我们希望相反(我们希望按屏幕上可见的高度而不是不可见的高度移动contentOffset):

activeField.frame.origin.y-(aRect.size.height)

试试看:

-(void)textFieldDidBeginEditing:(UITextField *)sender
{
    if ([sender isEqual:self.m_Sp_Contact])
    {
        [self.m_Scroller setContentOffset:CGPointMake(0, 105)animated:YES];          
    }
}