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

https://github.com/michaeltyson/TPKeyboardAvoiding下载此文件并添加自定义类,因为它将在您的表视图中管理所有内容,您无需执行任何操作。它有很多选项,你也可以为其他人查看,这是你需要避免使用键盘的全部

其他回答

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。

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];
}

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。

试试这个小把戏。

- (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 = textField.frame.origin.y / 2; // tweak as needed
    const float movementDuration = 0.3f; // tweak as needed

    int movement = (up ? -movementDistance : movementDistance);

    [UIView beginAnimations: @"anim" context: nil];
    [UIView setAnimationBeginsFromCurrentState: YES];
    [UIView setAnimationDuration: movementDuration];
    self.view.frame = CGRectOffset(self.view.frame, 0, movement);
    [UIView commitAnimations];
}

这对我有用:

func setupKeyboardNotifications() {
    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWasShown:"), name: UIKeyboardDidShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillBeHidden:"), name: UIKeyboardWillHideNotification, object: nil)
}

func keyboardWasShown(aNotification:NSNotification) {
    let info = aNotification.userInfo
    let infoNSValue = info![UIKeyboardFrameBeginUserInfoKey] as NSValue
    let kbSize = infoNSValue.CGRectValue().size
    UIView.beginAnimations(nil, context: nil)
    UIView.setAnimationDuration(0.3)
    var rect : CGRect = self.view.frame
    rect.size.height -= kbSize.height

    self.view.frame = rect
    UIView.commitAnimations()
}

func keyboardWillBeHidden(aNotification:NSNotification) {
    let info = aNotification.userInfo
    let infoNSValue = info![UIKeyboardFrameBeginUserInfoKey] as NSValue
    let kbSize = infoNSValue.CGRectValue().size
    UIView.beginAnimations(nil, context: nil)
    UIView.setAnimationDuration(0.3)
    var rect : CGRect = self.view.frame
    rect.size.height += kbSize.height
    self.view.frame = rect
    UIView.commitAnimations()
}