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

请遵循以下步骤。

1) 在.h文件中声明以下变量。

  {      
         CGFloat animatedDistance;
  }

2) 在.m文件中声明以下常量。

  static const CGFloat KEYBOARD_ANIMATION_DURATION = 0.3;
  static const CGFloat MINIMUM_SCROLL_FRACTION = 0.2;
  static const CGFloat MAXIMUM_SCROLL_FRACTION = 0.8;
  static const CGFloat PORTRAIT_KEYBOARD_HEIGHT = 216;
  static const CGFloat LANDSCAPE_KEYBOARD_HEIGHT = 162;

3) 使用UITextField代理向上/向下移动键盘。

  -(void) textFieldDidBeginEditing:(UITextField *)textField
  { 
         if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
         {
               CGRect textFieldRect = [self.view.window convertRect:textField.bounds fromView:textField];
               CGRect viewRect = [self.view.window convertRect:self.view.bounds fromView:self.view];

               CGFloat midline = textFieldRect.origin.y + 0.5 * textFieldRect.size.height;
               CGFloat numerator =
    midline - viewRect.origin.y
    - MINIMUM_SCROLL_FRACTION * viewRect.size.height;
               CGFloat denominator =
    (MAXIMUM_SCROLL_FRACTION - MINIMUM_SCROLL_FRACTION)
    * viewRect.size.height;
               CGFloat heightFraction = numerator / denominator;

               if (heightFraction < 0.0)
               {
                     heightFraction = 0.0;
               }
               else if (heightFraction > 1.0)
               {
                     heightFraction = 1.0;
               }

               UIInterfaceOrientation orientation =
    [[UIApplication sharedApplication] statusBarOrientation];
               if (orientation == UIInterfaceOrientationPortrait)
               {
                     animatedDistance = floor(PORTRAIT_KEYBOARD_HEIGHT * heightFraction);
               }
               else
               {
                     animatedDistance = floor(LANDSCAPE_KEYBOARD_HEIGHT * heightFraction);
               }

               CGRect viewFrame = self.view.frame;
               viewFrame.origin.y -= animatedDistance;

               [UIView beginAnimations:nil context:NULL];
               [UIView setAnimationBeginsFromCurrentState:YES];
               [UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];

               [self.view setFrame:viewFrame];

               [UIView commitAnimations];
       }
  }

  -(void) textFieldDidEndEditing:(UITextField *)textField
  {
       if(UI_USER_INTERFACE_IDIOM()==UIUserInterfaceIdiomPhone)
       {
             CGRect viewFrame = self.view.frame;
             viewFrame.origin.y += animatedDistance;

             [UIView beginAnimations:nil context:NULL];
             [UIView setAnimationBeginsFromCurrentState:YES];
             [UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];

             [self.view setFrame:viewFrame];

             [UIView commitAnimations];
       }
 }

其他回答

我已经为自己的需要制定了一个框架,以更好地解决这个问题,并将其公开。它不仅适用于UITextField和UITextView,还适用于采用UITextInput协议的任何自定义UIView,如UITextField或UITextView并提供许多有用的功能。您可以通过Carthage、CocoaPods或Swift Package Manager安装它。

ODScrollView GitHub

ODScrollView中等

ODScrollView只是一个UIScrollView,它根据键盘可见性自动垂直移动UITextField和UITextView等可编辑文本区域,以提供更好的用户体验。

特征

当键盘出现/消失时,自动向上/向下移动采用UITextInput协议的第一响应者UIView,例如UITextField、UITextView、UISearchTextField或任何采用UITextOutput协议的自定义UIView。注意,如果UITextInput的框架不适合ODScrollView和键盘之间的剩余区域,则ODScrollView将根据光标位置而不是框架调整UITextInput。在这种情况下,可以使用“trackTextInputCursor”功能。实例可以分别为每个UITextInput应用调整裕度,用于.顶部和.底部调整方向设置。默认情况下为20 CGFloat。可以分别为每个UITextInput启用/禁用调整。默认情况下为true。调整方向-顶部、中心、底部-可分别应用于每个UITextInput。默认情况下为底部。实例调整选项决定ODScrollView如何调整。始终默认。始终:无论UITextInput是否与显示的键盘重叠,ODScrollView始终调整放置在ODScrollView中任何位置的UITextInput。实例.IfNeedd:ODScrollView仅在UITextInput与显示的键盘重叠时调整UITextInput。实例除了UIScrollView.keyboardDismissModes之外,还可以通过点击ODScrollViewDelegate提供的UIView来关闭键盘。键盘关闭后,ODScrollView可以返回其原始位置。默认情况下为nil和false。实例

用法

1-您需要做的第一件事是正确设置ODScrollView及其内容视图。由于ODScrollView只是一个UIScrollView,所以您可以像对UIScroll View一样实现ODScroll视图。您可以使用故事板或编程方式创建ODScrollView。

如果您以编程方式创建ODScrollView,则可以从步骤4继续。

在情节提要中创建UIScrollView的建议方法

- If you are using Content Layout Guide and Frame Layout Guide:
    1.1 - scrollView: Place UIScrollView anywhere you want to use.  
    1.2 - contentView: Place UIView inside scrollView.
    1.3 - Set contentView's top, bottom, leading and trailing constraints to Content Layout Guide's constraints.
    1.4 - Set contentView's width equal to Frame Layout Guide's width.
    1.5 - Set contentView's height equal to Frame Layout Guide's height or set static height which is larger than scrollView's height.
    1.6 - Build your UI inside contentView.

- If you are NOT using Content Layout Guide and Frame Layout Guide:
    1.1 - scrollView: Place UIScrollView anywhere you want to use.  
    1.2 - contentView: Place UIView inside scrollView.
    1.3 - Set contentView's top, bottom, leading and trailing constraints to 0.
    1.4 - Set contentView's width equal to scrollView's width.
    1.5 - Set contentView's height equal to scrollView's superview's height or set static height which is larger than scrollView's height.
    1.6 - Build your UI inside contentView.

2-在Storyboard上的身份检查器中将scrollView的类从UIScrollView更改为ODScrollView。

3-在ViewController上为scrollView和contentView创建IBOutlets。

4-在ViewController上的ViewDidLoad()中调用以下方法:

override func viewDidLoad() {
    super.viewDidLoad()

    //ODScrollView setup
    scrollView.registerContentView(contentView)
    scrollView.odScrollViewDelegate = self
}  

5-可选:您仍然可以使用UIScrollView的功能:

override func viewDidLoad() {
    super.viewDidLoad()

    //ODScrollView setup
    scrollView.registerContentView(contentView)
    scrollView.odScrollViewDelegate = self

    // UIScrollView setup
    scrollView.delegate = self // UIScrollView Delegate
    scrollView.keyboardDismissMode = .onDrag // UIScrollView keyboardDismissMode. Default is .none.

    UITextView_inside_contentView.delegate = self
}

6-采用ViewController中的ODScrollViewDelegate并决定ODScrollView选项:

extension ViewController: ODScrollViewDelegate {

    // MARK:- State Notifiers: are responsible for notifiying ViewController about what is going on while adjusting. You don't have to do anything if you don't need them.

    // #Optional
    // Notifies when the keyboard showed.
    func keyboardDidShow(by scrollView: ODScrollView) {}

    // #Optional
    // Notifies before the UIScrollView adjustment.
    func scrollAdjustmentWillBegin(by scrollView: ODScrollView) {}

    // #Optional
    // Notifies after the UIScrollView adjustment.
    func scrollAdjustmentDidEnd(by scrollView: ODScrollView) {}

    // #Optional
    // Notifies when the keyboard hid.
    func keyboardDidHide(by scrollView: ODScrollView) {}

    // MARK:- Adjustment Settings

    // #Optional
    // Specifies the margin between UITextInput and ODScrollView's top or bottom constraint depending on AdjustmentDirection
    func adjustmentMargin(for textInput: UITextInput, inside scrollView: ODScrollView) -> CGFloat {
        if let textField = textInput as? UITextField, textField == self.UITextField_inside_contentView {
            return 20
        } else {
            return 40
        }
    }

    // #Optional
    // Specifies that whether adjustment is enabled or not for each UITextInput seperately.
    func adjustmentEnabled(for textInput: UITextInput, inside scrollView: ODScrollView) -> Bool {
        if let textField = textInput as? UITextField, textField == self.UITextField_inside_contentView {
            return true
        } else {
            return false
        }
    }


    // Specifies adjustment direction for each UITextInput. It means that  some of UITextInputs inside ODScrollView can be adjusted to the bottom, while others can be adjusted to center or top.
    func adjustmentDirection(selected textInput: UITextInput, inside scrollView: ODScrollView) -> AdjustmentDirection {
        if let textField = textInput as? UITextField, textField == self.UITextField_inside_contentView {
            return .bottom
        } else {
            return .center
        }
    }

    /**
     - Always : ODScrollView always adjusts the UITextInput which is placed anywhere in the ODScrollView.
     - IfNeeded : ODScrollView only adjusts the UITextInput if it overlaps with the shown keyboard.
     */
    func adjustmentOption(for scrollView: ODScrollView) -> AdjustmentOption {
        .Always
    }

    // MARK: - Hiding Keyboard Settings

    /**
     #Optional

     Provides a view for tap gesture that hides keyboard.

     By default, keyboard can be dismissed by keyboardDismissMode of UIScrollView.

     keyboardDismissMode = .none
     keyboardDismissMode = .onDrag
     keyboardDismissMode = .interactive

     Beside above settings:

     - Returning UIView from this, lets you to hide the keyboard by tapping the UIView you provide, and also be able to use isResettingAdjustmentEnabled(for scrollView: ODScrollView) setting.

     - If you return nil instead of UIView object, It means that hiding the keyboard by tapping is disabled.
     */
    func hideKeyboardByTappingToView(for scrollView: ODScrollView) -> UIView? {
        self.view
    }

    /**
     #Optional

     Resets the scroll view offset - which is adjusted before - to beginning its position after keyboard hid by tapping to the provided UIView via hideKeyboardByTappingToView.

     ## IMPORTANT:
     This feature requires a UIView that is provided by hideKeyboardByTappingToView().
     */
    func isResettingAdjustmentEnabled(for scrollView: ODScrollView) -> Bool {
        true
    }
}

7-可选:当在多行UITextInput中键入时光标与键盘重叠时,可以调整ODScrollView。trackTextInputCursor(用于UITextInput)必须由键入时激发的UITextInput函数调用。

/**
## IMPORTANT:
This feature is not going to work unless textView is subView of _ODScrollView
*/
func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
       _ODScrollView.trackTextInputCursor(for textView)
   return true
}

RPDP的代码成功地将文本字段移出键盘。但是当你在使用和关闭键盘后滚动到顶部时,顶部已经从视图中向上滚动。模拟器和设备都是如此。要读取该视图顶部的内容,必须重新加载该视图。

他下面的代码难道不应该使视图降低吗?

else
{
    // revert back to the normal state.
    rect.origin.y += kOFFSET_FOR_KEYBOARD;
    rect.size.height -= kOFFSET_FOR_KEYBOARD;
}
-(BOOL) textFieldShouldBeginEditing:(UITextField *)textField {

  [self slideUp];
   return YES;
}

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

    [self slideDown];
   return YES;
}

#pragma mark - Slide Up and Down animation

- (void) slideUp {
    [UIView beginAnimations:nil context:nil];
    layoutView.frame = CGRectMake(0.0, -70.0, layoutView.frame.size.width, layoutView.frame.size.height);

    [UIView commitAnimations];
}


- (void) slideDown {
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDelay: 0.01]; 
    layoutView.frame = CGRectMake(0.0, 0.0, layoutView.frame.size.width, layoutView.frame.size.height);
    [UIView commitAnimations];
}

我们可以为Swift 4.1提供用户给定的代码

    let keyBoardSize = 80.0

    func keyboardWillShow() {

    if view.frame.origin.y >= 0 {
    viewMovedUp = true
     }
     else if view.frame.origin.y < 0 {
    viewMovedUp = false
   }
  }

func keyboardWillHide() {
 if view.frame.origin.y >= 0 {
    viewMovedUp = true
 }
 else if view.frame.origin.y < 0 {
    viewMovedUp = false
 }

}

func textFieldDidBeginEditing(_ textField: UITextField) {
   if sender.isEqual(mailTf) {
    //move the main view, so that the keyboard does not hide it.
    if view.frame.origin.y >= 0 {
        viewMovedUp = true
    }
  }
}

func setViewMovedUp(_ movedUp: Bool) {
UIView.beginAnimations(nil, context: nil)
UIView.setAnimationDuration(0.3)
    // if you want to slide up the view
let rect: CGRect = view.frame
if movedUp {

    rect.origin.y -= keyBoardSize
    rect.size.height += keyBoardSize
}
else {
    // revert back to the normal state.
    rect.origin.y += keyBoardSize
    rect.size.height -= keyBoardSize
 }
 view.frame = rect
 UIView.commitAnimations()
}

func viewWillAppear(_ animated: Bool)  {
super.viewWillAppear(animated)

NotificationCenter.default.addObserver(self, selector:#selector(self.keyboardWillShow), name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector:#selector(self.keyboardWillHide), name: .UIKeyboardWillHide, object: nil)
}

func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)

NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillHide, object: nil)
}

这是我使用自动布局的版本:

其想法是将包含文本字段/文本视图的视图嵌入UIScrollView中,从底部到其超级视图设置一个约束,创建一个出口,并使用通知根据键盘高度更新其常量。这是基于此处的Apple示例,以及此处使用AutoLayout的UIScrollView上的Apple技术说明。

1) 将视图V嵌入UIScrollView S:如果已经设置了常量和子视图,则可以在ViewController的视图中复制/粘贴视图和子视图;然后使用编辑器->嵌入菜单嵌入视图,最后删除复制的视图。)

2) 设置以下约束:

S到顶部布局指南:0S至底部布局指南:0通向超级视图的S:0S尾随到超级视图:0V顶部空间到超级视图:0V底部空间到超级视图:0超级视图的V尾随空格:0超视图的V前导空格:0V等于S的宽度最新底部V子视图到超级视图:20

3) 从视图控制器的最新约束创建出口

4) 使用以下代码:

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

// ...

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    // ...

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

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

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Handle keyboard

// Called when the UIKeyboardDidShowNotification is sent.
- (void)keyboardWasShown:(NSNotification*)aNotification
{
    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    self.bottomSpaceToContentView.constant = kBottomMargin + kbSize.height;
    [self.view layoutIfNeeded];
}

// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
    self.bottomSpaceToContentView.constant = kBottomMargin;
    [self.view layoutIfNeeded];
}

哈哈,它起作用了!