要显示在键盘顶部的 UITextfield - 初学者

Question

我有textboxes。当我点击它时，键盘会弹出。但是，由于uitextfield 位于下方某个位置，因此当键盘弹出时它会被覆盖。 （键盘显示在文本字段上方，因此用户看不到它）。

我需要一种方法将textfield 向上移动，以便用户可以看到它。 iPhone facebook 应用程序有一个解决方法，它们缩小视图上的UIComponents 以在顶部显示textfield，因此它不会被键盘覆盖。

有人可以指点我开始使用的教程或示例代码吗？

Answer 1

OPTION-1：您可以参考以下链接中已被接受为答案的代码：

How to make a UITextField move up when keyboard is present?

这肯定会帮助您并为您提供所需的解决方案。

OPTION-2：这里还有一个现成的教程：

http://www.edumobile.org/iphone/iphone-programming-tutorials/scrollview-example-in-iphone/

我想你肯定会得到这个帮助

OPTION-3：你可以参考这个：

http://www.iphonesampleapps.com/2009/12/adjust-uitextfield-hidden-behind-keyboard-with-uiscrollview/

OPTION-4： Apple 文档：

https://developer.apple.com/library/ios/#DOCUMENTATION/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/KeyboardManagement/KeyboardManagement.html

希望对你有所帮助。

Answer 2

在 iOS9 上处理空间案例，例如预测文本的打开和关闭以及不同大小的键盘。

1. 用于存储默认视图框架的全局变量

var defaultFrame: CGRect!

1. 在 init() 中保存初始帧并订阅键盘通知

defaultFrame = self.frame
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyBoardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyBoardWillHide:", name: UIKeyboardWillHideNotification, object: nil)

1. 重定位视图的简单函数

func moveViewWithKeyboard(height: CGFloat) {
    self.frame = CGRectOffset(defaultFrame, 0, height)
}

4. 根据内部键盘偏移量移动

func keyBoardWillShow(notification: NSNotification) {
    let frame = (notification.userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue()
    moveViewWithKeyboard(-frame.height)
}
func keyBoardWillHide(notification: NSNotification) {
    moveViewWithKeyboard(0)
}

Answer 3

最好的方法是使用UIScrollView 并在需要开始编辑文本时将其向上移动。 这个问题/答案将为您提供设置它的粗略指南

How to make a UITextField move up when keyboard is present

Answer 4

它可以帮助你... bottomLayoutConstrain 是来自的底部约束 文本字段到您想要向上的视图底部。斯威夫特代码：

        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShowNotification:", name: UIKeyboardWillShowNotification, object: nil)

        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHideNotification:", name: UIKeyboardWillHideNotification, object: nil)


    func keyboardWillShowNotification(notification:NSNotification){
            let keyboardInfo:NSDictionary = notification.userInfo!

            let keyboardFrameBegin:AnyObject = keyboardInfo.valueForKey(UIKeyboardFrameEndUserInfoKey)!
            keyboardFrameBeginRect = keyboardFrameBegin.CGRectValue

            self.view.layoutIfNeeded()
            self.bottomLayoutConstrain.constant = self.keyboardFrameBeginRect!.height
            self.view.layoutIfNeeded()
        }


    func keyboardWillHideNotification(notification:NSNotification){

        self.view.layoutIfNeeded()
        bottomLayoutConstrain?.constant = 0
        self.view.layoutIfNeeded()
    }

    deinit {
        // perform the deinitialization
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
        //        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardDidShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
    }

目标c代码

- (void)viewDidLoad {
    [super viewDidLoad];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShowNotification:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHideNotification:) name:UIKeyboardWillHideNotification object:nil];
}

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

-(void) keyboardWillShowNotification:(NSNotification *) notification{
    NSDictionary *keyboardInfo = notification.userInfo;

    keyboardFrameBeginRect = [keyboardInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];

    [self.view layoutIfNeeded];

    //    [UIView animateWithDuration:1.0 animations:^{
    topLayoutConstraints.constant = -keyboardFrameBeginRect.size.height;
    bottomLayoutConstrain.constant = keyboardFrameBeginRect.size.height;
    //    }];

    [self.view layoutIfNeeded];
}

-(void) keyboardWillHideNotification:(NSNotification *) notification{

    [self.view layoutIfNeeded];

    topLayoutConstraints.constant = 0;
    bottomLayoutConstrain.constant = 0;

    [self.view layoutIfNeeded];
}