切换 UITextField 时调整键盘视图？

Question

当键盘出现在我的应用程序中时，我的视图可以向上滑动，以便可以看到文本字段并且效果很好。但是，由于它基于键盘通知，因此它仅在键盘出现时才起作用。

意思是，我选择一个文本字段，键盘出现，视图相应地向上滑动，但如果我直接点击另一个文本字段，视图不会调整，因为键盘已经存在。

这是我正在使用的代码，非常感谢任何帮助使其适应上述情况的帮助。

-(void)registerForKeyboardNotifications
{
    NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
    [center addObserver:self selector:@selector(keyboardDidShow:) name:UIKeyboardDidShowNotification object:nil];
    [center addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];

    // add a tap gesture to drop first responder
    UITapGestureRecognizer *tapGR = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapToHideKeyboard:)];
    [self.view addGestureRecognizer:tapGR];
}

-(void)keyboardDidShow:(NSNotification *)notification
{
    CGRect keyboardFrameW = [[notification.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    UIWindow *window = [[UIApplication sharedApplication] keyWindow];
    CGRect keyboardFrame = [window convertRect:keyboardFrameW toView:self.view];

    //Have a minimum space between the keyboard and textfield
    CGFloat textFieldBuffer = 40;
    CGFloat textFieldKeyboardDifference = 0;

    if (activeTextField.frame.origin.y + activeTextField.frame.size.height > keyboardFrame.origin.y) textFieldKeyboardDifference = (activeTextField.frame.origin.y + activeTextField.frame.size.height + textFieldBuffer) - keyboardFrame.origin.y;
    else if (activeTextField.frame.origin.y + activeTextField.frame.size.height < keyboardFrame.origin.y) textFieldKeyboardDifference = 0;

    [self translateView:self.view toRect:CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y - textFieldKeyboardDifference, self.view.frame.size.width, self.view.frame.size.height) withDuration:0.3];
}

-(void)keyboardWillHide:(NSNotification *)notification
{
    //Revert to y origin 0
    [self translateView:self.view toRect:CGRectMake(self.view.frame.origin.x, 0, self.view.frame.size.width, self.view.frame.size.height) withDuration:0.3];
}

编辑：

当textFieldDidBeginEditing 被这样调用时，我尝试手动调用键盘通知：

[self keyboardDidShow:[NSNotification notificationWithName:UIKeyboardDidShowNotification object:nil]]; 没有运气。该方法被调用，但由于我无法解决的原因未进行任何调整。

Answer 1

您可能想要在这里做的是为您的所有UITextFields 提供一个委托，并在该委托上实现- (void)textFieldDidBeginEditing:(UITextField *)textField 以触发您的滚动操作。这将在有人开始编辑文本字段时调用，并且文本字段作为参数传递给方法。

编辑：以您的代码为起点，这就是我想出的。每次更改文本字段时都会调用它：

@interface SOViewController () <UITextFieldDelegate>
@property (nonatomic, readwrite, assign) UITextField* activeTextField;
@property (nonatomic, readwrite, assign) CGRect keyboardFrame;
@end

@implementation SOViewController

@synthesize activeTextField;
@synthesize keyboardFrame;

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    [self registerForKeyboardNotifications];
    self.keyboardFrame = CGRectNull;
}

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    self.activeTextField = textField;
    [self updatePosition];
}

- (void)textFieldDidEndEditing:(UITextField *)textField
{
    self.activeTextField = nil;
}

-(void)registerForKeyboardNotifications
{
    NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
    [center addObserver:self selector:@selector(keyboardDidShow:) name:UIKeyboardDidShowNotification object:nil];
    [center addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];

    //    // add a tap gesture to drop first responder
    //    UITapGestureRecognizer *tapGR = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapToHideKeyboard:)];
    //    [self.view addGestureRecognizer:tapGR];
}

- (void)translateView: (UIView*)view toRect: (CGRect)rect withDuration: (NSTimeInterval)duration
{
    NSLog(@"Translating view to rect: %@ overDuration: %g", NSStringFromCGRect(rect), duration);
}

- (void)updatePosition
{
    if (self.activeTextField && !CGRectIsNull(self.keyboardFrame))
    {
        UIWindow *window = [[UIApplication sharedApplication] keyWindow];
        CGRect localKeyboardFrame = [window convertRect: self.keyboardFrame toView:self.view];

        //Have a minimum space between the keyboard and textfield
        CGFloat textFieldBuffer = 40;

        CGRect textFieldFrame = self.activeTextField.frame;

        CGRect viewFrame = self.view.frame;
        viewFrame.origin.y = 0;

        if (CGRectGetMaxY(textFieldFrame) + textFieldBuffer > CGRectGetMinY(localKeyboardFrame))
        {
            viewFrame.origin.y = -1.0 * (CGRectGetMaxY(textFieldFrame) + textFieldBuffer - CGRectGetMinY(localKeyboardFrame));
        }

        [self translateView: self.view toRect: viewFrame withDuration: 0.3];

    }
    else
    {
        CGRect viewFrame = self.view.frame;
        viewFrame.origin.y = 0;
        [self translateView: self.view toRect: viewFrame withDuration: 0.3];
    }
}

-(void)keyboardDidShow:(NSNotification *)notification
{
    self.keyboardFrame = [[notification.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    [self updatePosition];
}

-(void)keyboardWillHide:(NSNotification *)notification
{
    self.keyboardFrame = CGRectNull;
    [self updatePosition];
}

@end

Answer 2

我喜欢在像你这样的情况下使用UITableViewController 子类。只需使用UITableView 页眉页脚和单元格构建您的视图。当您需要在UITextView 或字段UITableViewController 中进行文本编辑时，将自动布局所有内容。

即使您将scrollEnabled 属性设置为 NO，它也会起作用；