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

下面是带有文本字段的滚动视图的简单解决方案,不需要任何约束或活动文本字段等。。。

 override func viewWillAppear(_ animated: Bool){
        super.viewWillAppear(animated)
        registerForKeyboardNotifications();


    }
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        deregisterFromKeyboardNotifications();
    }
    //MARK:- KEYBOARD DELEGATE METHODS
        func registerForKeyboardNotifications(){
            //Adding notifies on keyboard appearing
            NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
            NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillBeHidden(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
        }
        func deregisterFromKeyboardNotifications(){
            //Removing notifies on keyboard appearing
            NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
            NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
        }
        func keyboardWasShown(notification: NSNotification){

            var info = notification.userInfo!
            let keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size
            var contentInset:UIEdgeInsets = self.scrRegister.contentInset
            contentInset.bottom = (keyboardSize?.height)!
            scrRegister.contentInset = contentInset


        }
        func keyboardWillBeHidden(notification: NSNotification)
        {
            var contentInset:UIEdgeInsets = self.scrRegister.contentInset
            contentInset.bottom = 0
            scrRegister.contentInset = contentInset

        }

其他回答

如果您现在的内容不适合iPhone屏幕,您只需要一个ScrollView。(如果您添加ScrollView作为组件的超级视图,只是为了在键盘启动时使TextField向上滚动,那么就不需要了。)防止TextFields被键盘覆盖的标准方法是在显示键盘时向上/向下移动视图。

下面是一些示例代码:

#define kOFFSET_FOR_KEYBOARD 80.0

-(void)keyboardWillShow {
    // Animate the current view out of the way
    if (self.view.frame.origin.y >= 0)
    {
        [self setViewMovedUp:YES];
    }
    else if (self.view.frame.origin.y < 0)
    {
        [self setViewMovedUp:NO];
    }
}

-(void)keyboardWillHide {
    if (self.view.frame.origin.y >= 0)
    {
        [self setViewMovedUp:YES];
    }
    else if (self.view.frame.origin.y < 0)
    {
        [self setViewMovedUp:NO];
    }
}

-(void)textFieldDidBeginEditing:(UITextField *)sender
{
    if ([sender isEqual:mailTf])
    {
        //move the main view, so that the keyboard does not hide it.
        if  (self.view.frame.origin.y >= 0)
        {
            [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 -= kOFFSET_FOR_KEYBOARD;
        rect.size.height += kOFFSET_FOR_KEYBOARD;
    }
    else
    {
        // revert back to the normal state.
        rect.origin.y += kOFFSET_FOR_KEYBOARD;
        rect.size.height -= kOFFSET_FOR_KEYBOARD;
    }
    self.view.frame = rect;

    [UIView commitAnimations];
}


- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    // register for keyboard notifications
    [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillShow)
                                             name:UIKeyboardWillShowNotification
                                           object:nil];

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

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

    [[NSNotificationCenter defaultCenter] removeObserver:self
                                             name:UIKeyboardWillHideNotification
                                           object:nil];
}

我把所有的东西都放在一节课上。加载视图控制器时,只需调用以下代码行:

- (void)viewDidLoad {
    [super viewDidLoad];
    KeyboardInsetScrollView *injectView = [[KeyboardInsetScrollView alloc] init];
    [injectView injectToView:self.view withRootView:self.view];
}

以下是示例项目的链接:https://github.com/caohuuloc/KeyboardInsetScrollView

从以下链接下载TPKeyBoardAvoiding:https://github.com/michaeltyson/TPKeyboardAvoiding. 展开zipped文件夹,找到TPKeyboardAvoiding文件夹。选择所有.h和.m文件,并将其放到项目中。确保选中了复制项(如果需要)。将UIScrollView拖放到StoryBoard并与TPKeyboardAvoidingScrollView关联。现在,您可以在滚动视图的顶部添加UI元素。注意,即使在拖动scrollView之后,这个类也会检测UI元素的触摸。

在ViewController上:

@IBOutlet weak var usernameTextfield: UITextField!
@IBOutlet weak var passwordTextfield: UITextField!
@IBOutlet weak var loginScrollView: UIScrollView!


override func viewWillAppear(animated: Bool) {
        loginScrollView.scrollEnabled =  false
    }

添加TextField委托。

//MARK:- TEXTFIELD METHODS
func textFieldShouldReturn(textField: UITextField) -> Bool
{
    if (usernameTextfield.resignFirstResponder())
    {
        passwordTextfield.becomeFirstResponder()
    }
    textField.resignFirstResponder();
    loginScrollView!.setContentOffset(CGPoint.zero, animated: true);
    loginScrollView.scrollEnabled =  false
    return true
}
func textFieldDidBeginEditing(textField: UITextField)
{
    loginScrollView.scrollEnabled =  true

    if (textField.tag  == 1 && (device == "iPhone" || device == "iPhone Simulator" || device == "iPod touch"))
    {
        let scrollPoint:CGPoint = CGPointMake(0, passwordTextfield.frame.origin.y/6.4);
        loginScrollView!.setContentOffset(scrollPoint, animated: true);

    }
    else if (textField.tag  == 2 && (device == "iPhone" || device == "iPhone Simulator" || device == "iPod touch"))
    {
        let scrollPoint:CGPoint = CGPointMake(0, passwordTextfield.frame.origin.y/6.0);
        loginScrollView!.setContentOffset(scrollPoint, animated: true);
    }
}
func textFieldDidEndEditing(textField: UITextField)
{
    loginScrollView!.setContentOffset(CGPointZero,animated: true);
}

在视图中设置滚动视图

  - (void)textFieldDidBeginEditing:(UITextField *)textField
    {
     CGPoint point;
    if(textField == txtEmail){
      // -90 is for my you can change as per your postion
      point = CGPointMake(0, textField.frame.origin.y - 90);
    }
    else if (textField == txtContact){
      point = CGPointMake(0, textField.frame.origin.y - 90);
    }
      [scrollV setContentOffset:point animated:YES];
    }

虽然这条线索已经得到了足够的答案,但我想建议一种更简单但更通用的方法,就像苹果一样,将键盘的高度考虑在内,这在我们使用键盘顶部的自定义工具栏时非常有用。尽管苹果在这方面的做法没有什么问题。

这是我的方法(略微修改了苹果的方法)-

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

    UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
    self.scrollView.contentInset = contentInsets;
    self.scrollView.scrollIndicatorInsets = contentInsets;
}

// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
    UIEdgeInsets contentInsets = UIEdgeInsetsZero;
    self.scrollView.contentInset = contentInsets;
    self.scrollView.scrollIndicatorInsets = contentInsets;
}