如果文本字段应该位于屏幕底部，那么最神奇的解决方案是在视图控制器上覆盖以下内容：

override var inputAccessoryView: UIView? {
    return <yourTextField>
}

已经有很多答案了，但上面的解决方案仍然没有一个具备“完美”无bug、向后兼容和无闪烁动画所需的所有花哨定位功能。（在一起设置帧/边界和contentOffset动画时出错，界面方向不同，iPad分割键盘等）让我分享我的解决方案：（假设您已设置UIKeyboardWill（显示|隐藏）通知）

// Called when UIKeyboardWillShowNotification is sent
- (void)keyboardWillShow:(NSNotification*)notification
{
    // if we have no view or are not visible in any window, we don't care
    if (!self.isViewLoaded || !self.view.window) {
        return;
    }

    NSDictionary *userInfo = [notification userInfo];

    CGRect keyboardFrameInWindow;
    [[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] getValue:&keyboardFrameInWindow];

    // the keyboard frame is specified in window-level coordinates. this calculates the frame as if it were a subview of our view, making it a sibling of the scroll view
    CGRect keyboardFrameInView = [self.view convertRect:keyboardFrameInWindow fromView:nil];

    CGRect scrollViewKeyboardIntersection = CGRectIntersection(_scrollView.frame, keyboardFrameInView);
    UIEdgeInsets newContentInsets = UIEdgeInsetsMake(0, 0, scrollViewKeyboardIntersection.size.height, 0);

    // this is an old animation method, but the only one that retains compaitiblity between parameters (duration, curve) and the values contained in the userInfo-Dictionary.
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
    [UIView setAnimationCurve:[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];

    _scrollView.contentInset = newContentInsets;
    _scrollView.scrollIndicatorInsets = newContentInsets;

    /*
     * Depending on visual layout, _focusedControl should either be the input field (UITextField,..) or another element
     * that should be visible, e.g. a purchase button below an amount text field
     * it makes sense to set _focusedControl in delegates like -textFieldShouldBeginEditing: if you have multiple input fields
     */
    if (_focusedControl) {
        CGRect controlFrameInScrollView = [_scrollView convertRect:_focusedControl.bounds fromView:_focusedControl]; // if the control is a deep in the hierarchy below the scroll view, this will calculate the frame as if it were a direct subview
        controlFrameInScrollView = CGRectInset(controlFrameInScrollView, 0, -10); // replace 10 with any nice visual offset between control and keyboard or control and top of the scroll view.

        CGFloat controlVisualOffsetToTopOfScrollview = controlFrameInScrollView.origin.y - _scrollView.contentOffset.y;
        CGFloat controlVisualBottom = controlVisualOffsetToTopOfScrollview + controlFrameInScrollView.size.height;

        // this is the visible part of the scroll view that is not hidden by the keyboard
        CGFloat scrollViewVisibleHeight = _scrollView.frame.size.height - scrollViewKeyboardIntersection.size.height;

        if (controlVisualBottom > scrollViewVisibleHeight) { // check if the keyboard will hide the control in question
            // scroll up until the control is in place
            CGPoint newContentOffset = _scrollView.contentOffset;
            newContentOffset.y += (controlVisualBottom - scrollViewVisibleHeight);

            // make sure we don't set an impossible offset caused by the "nice visual offset"
            // if a control is at the bottom of the scroll view, it will end up just above the keyboard to eliminate scrolling inconsistencies
            newContentOffset.y = MIN(newContentOffset.y, _scrollView.contentSize.height - scrollViewVisibleHeight);

            [_scrollView setContentOffset:newContentOffset animated:NO]; // animated:NO because we have created our own animation context around this code
        } else if (controlFrameInScrollView.origin.y < _scrollView.contentOffset.y) {
            // if the control is not fully visible, make it so (useful if the user taps on a partially visible input field
            CGPoint newContentOffset = _scrollView.contentOffset;
            newContentOffset.y = controlFrameInScrollView.origin.y;

            [_scrollView setContentOffset:newContentOffset animated:NO]; // animated:NO because we have created our own animation context around this code
        }
    }

    [UIView commitAnimations];
}


// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillHide:(NSNotification*)notification
{
    // if we have no view or are not visible in any window, we don't care
    if (!self.isViewLoaded || !self.view.window) {
        return;
    }

    NSDictionary *userInfo = notification.userInfo;

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:[[userInfo valueForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
    [UIView setAnimationCurve:[[userInfo valueForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];

    // undo all that keyboardWillShow-magic
    // the scroll view will adjust its contentOffset apropriately
    _scrollView.contentInset = UIEdgeInsetsZero;
    _scrollView.scrollIndicatorInsets = UIEdgeInsetsZero;

    [UIView commitAnimations];
}

对于通用解决方案，这是我实现IQKeyboardManager的方法。

步骤1:-我在单例类中添加了UITextField、UITextView和UIKeyboard的全局通知。我叫它IQKeyboardManager。

步骤2:-如果找到UIKeyboardWillShowNotification、UITextFieldTextDidBegginEditingNotification或UITextViewTextDidBedginEditingNotice通知，我尝试从UIWindow.rootViewController层次结构获取topMostViewController实例。为了正确显示UITextField/UITextView，需要调整topMostViewController.view的框架。

步骤3:-我计算了topMostViewController.view相对于第一个响应的UITextField/UITextView的预期移动距离。

步骤4:-我根据预期的移动距离向上/向下移动topMostViewController.view.frame。

步骤5:-如果找到UIKeyboardWillHideNotification、UITextFieldTextDidEndEditingNotification或UITextViewTextDidEndEditingNotification通知，我再次尝试从UIWindow.rootViewController层次结构获取topMostViewController实例。

步骤6：-我计算了topMostViewController.view的干扰距离，需要将其恢复到原始位置。

第7步：-我根据干扰距离恢复了topMostViewController.view.frame。

步骤8:-我在应用程序加载时实例化了单例IQKeyboardManager类实例，因此应用程序中的每个UITextField/UUITextView都将根据预期的移动距离自动调整。

这就是IQKeyboardManager在没有代码行的情况下为您所做的一切！！只需将相关的源文件拖放到项目即可。IQKeyboardManager还支持设备定向、自动UIToolbar管理、KeybkeyboardDistanceFromTextField等功能，远远超出您的想象。

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];
}

这里是我创建的UITextfield（和其他类似的字段）类别，它将使文本字段避开键盘，您应该能够将其按原样放置在视图控制器中，它应该可以工作。它将整个屏幕向上移动，使当前文本字段位于带有动画的键盘上方

#import "UIView+avoidKeyboard.h"
#import "AppDelegate.h"

@implementation UIView (avoidKeyboard)

- (void) becomeFirstResponder {

if(self.isFirstResponder)
    return;

[super becomeFirstResponder];

if ([self isKindOfClass:[UISearchBar class]] ||
    [self isKindOfClass:[UITextField class]] ||
    [self isKindOfClass:[UITextView class]])
{
    AppDelegate *appDelegate    = [UIApplication sharedApplication].delegate;

    CGRect screenBounds         = appDelegate.window.frame;

    CGFloat keyboardHeight;
    CGFloat keyboardY;
    CGFloat viewsLowestY;
    CGPoint origin              = [self.superview convertPoint:self.frame.origin toView:appDelegate.window]; //get this views origin in terms of the main screens bounds

    if(UIInterfaceOrientationIsPortrait([[UIApplication sharedApplication] statusBarOrientation])){ //the window.frame doesnt take its orientation into account so if its sideways we must use the x value of the origin instead of the y
        keyboardHeight          = 216;
        keyboardY               = screenBounds.size.height  - keyboardHeight; //find the keyboards y coord relative to how much the main window has moved up
        viewsLowestY            = origin.y + self.frame.size.height; //find the lowest point of this view
    }
    else {
        keyboardHeight          = 162;
        keyboardY               = screenBounds.size.width  - keyboardHeight;
        viewsLowestY            = origin.x + self.frame.size.height;
    }

    CGFloat difference          = viewsLowestY - keyboardY + 20; //find if this view overlaps with the keyboard with some padding

    if (difference > 0){ //move screen up if there is an overlap

        [UIView animateWithDuration:0.3 delay:0.0 options:UIViewAnimationOptionBeginFromCurrentState animations:^{

            CGRect frame = appDelegate.window.frame;

            if(UIInterfaceOrientationIsPortrait([[UIApplication sharedApplication] statusBarOrientation])){
                frame.origin.y -= difference;
            }
            else {
                frame.origin.x -= difference;
            }
            appDelegate.window.frame = frame;
        }
        completion:nil];
    }
}
}

//look at appDelegate to see when the keyboard is hidden

@end

在appDelegate中添加此函数

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardHides:) name:UIKeyboardWillHideNotification object:nil]; //add in didFinishLaunchingWithOptions

...

- (void)keyboardHides:(NSNotification *)notification
{
    [UIView animateWithDuration:0.3 animations:^{
        [window setFrame: CGRectMake(0, 0, window.frame.size.width, window.frame.size.height)];
    } completion:nil];
}

仅使用文本字段：

1a）使用界面生成器：选择所有文本字段=>编辑=>嵌入=>滚动视图

1b）在UIScrollView中手动嵌入文本字段，称为scrollView

2） 设置UITextFieldDelegate

3） 设置每个textField.delegate=self；（或在Interface Builder中建立连接）

4） 复制/粘贴：

- (void)textFieldDidBeginEditing:(UITextField *)textField {
    CGPoint scrollPoint = CGPointMake(0, textField.frame.origin.y);
    [scrollView setContentOffset:scrollPoint animated:YES];
}

- (void)textFieldDidEndEditing:(UITextField *)textField {
    [scrollView setContentOffset:CGPointZero animated:YES];
}