ios 当键盘位于文本字段上时移动 ScrollView

Question

拜托，你能更正我的代码吗，所以我有一个简单的应用程序示例，当键盘位于其上方时，文本字段会向上移动？

我尝试使用来自 ios 开发人员库的代码来实现它 https://developer.apple.com/library/ios/documentation/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/KeyboardManagement/KeyboardManagement.html

但我不知道“事件字段存储在自定义变量中(在本例中称为 activeField)”是什么意思，我可能做错了什么。在 viewWillAppear 中使用 registerForKeyboardNotifications 可以吗？

我知道有一些关于这个问题的线索，但我是新手，很难理解它们。而且我不想只是学习如何，而是为什么，这就是为什么我不想使用其他人建议的 github 中现成的解决方案等。

我的自动取款机代码:

.h:

#import <UIKit/UIKit.h>

@interface VNViewController : UIViewController<UIScrollViewDelegate, UITextFieldDelegate>

@property (weak, nonatomic) IBOutlet UITextField *texticek;
@property (strong, nonatomic) IBOutlet UIScrollView *scrollView;

@end

.m:

#import "VNViewController.h"

@interface VNViewController ()

@end


@implementation VNViewController

@synthesize scrollView;
@synthesize texticek;

- (void) viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [self registerForKeyboardNotifications];
}

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

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
// Call this method somewhere in your view controller setup code.
- (void)registerForKeyboardNotifications
{
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasShown:)
                                                 name:UIKeyboardDidShowNotification object:nil];

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

}

// 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);
    scrollView.contentInset = contentInsets;
    scrollView.scrollIndicatorInsets = contentInsets;

    // If active text field is hidden by keyboard, scroll it so it's visible
    // Your app might not need or want this behavior.
    CGRect aRect = self.view.frame;
    aRect.size.height -= kbSize.height;
    if (!CGRectContainsPoint(aRect, activeField.frame.origin) ) {
        [self.scrollView scrollRectToVisible:activeField.frame animated:YES];
    }
}

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

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    activeField = textField;
}

- (void)textFieldDidEndEditing:(UITextField *)textField
{
    activeField = nil;
}

@end

Answer 1

点击文本框向上移动，使用下面的代码。它只需要你的卷轴导出

- (void)textFieldDidBeginEditing:(UITextField *)textField {

    self.scroll.contentOffset = CGPointMake(0, textField.frame.origin.y);
}

您可以通过减去 y 位置值(textfield.frame.origin.y - 一些值)来更改应该出现的文本字段的位置

如果你想为滚动设置动画，你可以这样做:

CGPoint newOffset = CGPointMake(0, textField.frame.origin.y-40);
[self.scroll setContentOffset: newOffset animated: YES];