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

一直在为初学者寻找关于这个主题的好教程,在这里找到了最好的教程。

在教程底部的MIScrollView.h示例中,确保在

@property (nonatomic, retain) id backgroundTapDelegate;

如您所见。

其他回答

这是独立于设备的偏移计算。获取键盘和文本字段之间的重叠高度:

func keyboardShown(notification: NSNotification) {
    let info  = notification.userInfo!
    let value: AnyObject = info[UIKeyboardFrameEndUserInfoKey]!

    let rawFrame = value.CGRectValue
    let keyboardFrame = view.convertRect(rawFrame, fromView: nil)

    let screenHeight = UIScreen.mainScreen().bounds.size.height;
    let Ylimit = screenHeight - keyboardFrame.size.height
    let textboxOriginInSuperview:CGPoint = self.view.convertPoint(CGPointZero, fromCoordinateSpace: lastTextField!)

    self.keyboardHeight = (textboxOriginInSuperview.y+self.lastTextField!.frame.size.height) - Ylimit

    if(self.keyboardHeight>0){
        self.animateViewMoving(true, moveValue: keyboardHeight!)
    }else{
        keyboardHeight=0
    }
}

keyBoardHeight是偏移量。

我在这里没有看到这种可能性,所以我添加了它,因为我尝试了答案中的方法,但几个小时后发现在iOS6/7中的XCode 5中有一种更简单的方法:使用NSLayoutConstraints。

请参见:自动布局约束-键盘

这是我的代码:

.m文件:

// Called when the UIKeyboardWillShowNotification is sent.
- (void)keyboardWillBeShown:(NSNotification*)aNotification
{
    NSLog(@"keyboardWillBeShown:");
    [self.PhoneNumberLabelOutlet setHidden:TRUE];
    CGFloat heightOfLabel = self.PhoneNumberLabelOutlet.frame.size.height;
    for( NSLayoutConstraint* thisConstraint in self.topElementsVerticalDistanceFromTopLayoutConstraint ) {
        thisConstraint.constant -= heightOfLabel;
    }

    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    CGFloat oldConstant = [self.SignInYConstraint constant];
    self.SignInYConstraint.constant = oldConstant + kbSize.height;
    [self.view setNeedsUpdateConstraints];

    NSTimeInterval duration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    [UIView animateWithDuration:duration animations:^{
        [self.view layoutIfNeeded];
    }];

}

.h文件:

#import <UIKit/UIKit.h>

@interface SignInViewController : UIViewController {

    UITextField* _activeField;
}




- (void)signInCallback:(NSObject*)object;


@property (weak, nonatomic) IBOutlet UILabel *PhoneNumberLabelOutlet;

@property (weak, nonatomic) IBOutlet UIActivityIndicatorView *ActivityIndicatorOutlet;

@property (weak, nonatomic) IBOutlet UITextField *UserIDTextfieldOutlet;

@property (weak, nonatomic) IBOutlet UITextField *PasswordTextfieldOutlet;

@property (weak, nonatomic) IBOutlet UIButton *SignInButton;

@property (weak, nonatomic) IBOutlet NSLayoutConstraint *SignInYConstraint;

@property (strong, nonatomic) IBOutletCollection(NSLayoutConstraint) NSArray *topElementsVerticalDistanceFromTopLayoutConstraint;

@end

添加我的5美分:)

我总是喜欢使用tableView作为inputTextField或scrollView。结合通知,您可以轻松管理此类行为。(注意,如果您在tableView中使用静态单元格,则这种行为将自动为您管理。)

// MARK: - Notifications
fileprivate func registerNotificaitions() {
    NotificationCenter.default.addObserver(self, selector: #selector(AddRemoteControlViewController.keyboardWillAppear(_:)),
                                           name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(AddRemoteControlViewController.keyboardWillDisappear),
                                           name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}

fileprivate func unregisterNotifications() {
    NotificationCenter.default.removeObserver(self)
}

@objc fileprivate func keyboardWillAppear(_ notification: Notification) {
    if let keyboardHeight = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue.height {
        view.layoutIfNeeded()
        UIView.animate(withDuration: 0.3, animations: {
            let heightInset = keyboardHeight - self.addDeviceButton.frame.height
            self.tableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: heightInset, right: 0)
            self.view.layoutIfNeeded()
        }, completion: nil)
    }
}

@objc fileprivate func keyboardWillDisappear() {
    view.layoutIfNeeded()
    UIView.animate(withDuration: 0.3, animations: {
        self.tableView.contentInset = UIEdgeInsets.zero
        self.view.layoutIfNeeded()
    }, completion: nil)
}

对于Swift程序员:

这将为您完成所有工作,只需将这些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:改变

self.view.frame = CGRectOffset(self.view.frame, 0,  movement)

to

self.view.frame = self.view.frame.offsetBy(dx: 0, dy: movement)

关于此实现的最后一点注意事项:如果在显示键盘时将另一个视图控制器推到堆栈上,这将产生一个错误,其中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,但随后您按下一个按钮,将帮助视图控制器推到堆栈上。若要修复偏移错误,请确保在离开视图控制器之前调用nameField.issentFirstResponder(),确保同时调用textFieldDidEndEditing委托方法。我在viewWillDisappear方法中这样做。

Swift 2.0版本:

添加UIScrollView并在其顶部添加textFields。将故事板引用到VC。

@IBOutlet weak var username: UITextField!
@IBOutlet weak var password: UITextField!
@IBOutlet weak var scrollView: UIScrollView!

添加以下方法:UITextFieldDelegate和UIScrollViewDelegate。

//MARK:- TEXTFIELD METHODS
    func textFieldShouldReturn(textField: UITextField) -> Bool {

        if(username.returnKeyType == UIReturnKeyType.Default) {
            password.becomeFirstResponder()
        }
        textField.resignFirstResponder()
        return true
    }
    func textFieldDidBeginEditing(textField: UITextField) {

        dispatch_async(dispatch_get_main_queue()) {

            let scrollPoint:CGPoint = CGPointMake(0,textField.frame.origin.y/4)
            self.scrollView!.setContentOffset(scrollPoint, animated: true);
        }
    }
    func textFieldShouldEndEditing(textField: UITextField) -> Bool {

        dispatch_async(dispatch_get_main_queue()) {
          UIView.animateWithDuration(0, animations: { self.scrollView!.setContentOffset(CGPointZero,animated: true) })
        }
        return true
    }
    override func touchesBegan(touches: Set<UITouch>,
        withEvent event: UIEvent?) {
            self.view.endEditing(true)
    }
    func scrollViewWillBeginDragging(scrollView: UIScrollView) {
        self.scrollView.scrollEnabled =  true

        dispatch_async(dispatch_get_main_queue()) {
            UIView.animateWithDuration(0, animations: { self.scrollView!.setContentOffset(CGPointZero,animated: true)

            })
        }
    }