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

试试这个,效果很好:

if Firstnametxt.text == "" || Passwordtxt.text == "" || emailtxt.text == ""
    {
        if Firstnametxt.text == ""
        {
            Firstnametxt!.shake(10, withDelta: 5, speed: 0.05, shakeDirection: ShakeDirection.Horizontal)
            Firstnametxt.becomeFirstResponder()
        }
        else if Passwordtxt.text == ""
        {
            Passwordtxt!.shake(10, withDelta: 5, speed: 0.05, shakeDirection: ShakeDirection.Horizontal)
            Passwordtxt.becomeFirstResponder()
        }
        else if emailtxt.text == ""

        {

            emailtxt!.shake(10, withDelta: 5, speed: 0.05, shakeDirection: ShakeDirection.Horizontal)
            emailtxt.becomeFirstResponder()
        }

    }
    else
    {
        let isValidEmail:Bool = self.isValidEmail(emailtxt.text!)
        if isValidEmail == true
        {
                        }
        else
        {
            emailtxt!.shake(10, withDelta: 5, speed: 0.05, shakeDirection: ShakeDirection.Horizontal)
            emailtxt.becomeFirstResponder()

        }

    }

其他回答

一种更简单但通用的方法,就像苹果的做法一样,将键盘的高度考虑在内,这在我们使用键盘顶部的自定义工具栏时非常有用。尽管苹果在这方面的做法没有什么问题。

这是我的方法(略微修改了苹果的方法)-

// UIKeyboardDidShowNotification
- (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);
    self.scrollView.contentInset = contentInsets;
    self.scrollView.scrollIndicatorInsets = contentInsets;
}

// UIKeyboardWillHideNotification
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
    UIEdgeInsets contentInsets = UIEdgeInsetsZero;
    self.scrollView.contentInset = contentInsets;
    self.scrollView.scrollIndicatorInsets = contentInsets;
}

我认为如果您使用Swift,最好的方法是使用面向协议的编程。

首先,您必须创建KeyboardCapable协议,使符合该协议的任何UIViewController都能够注册和注销键盘观察员:

import Foundation
import UIKit

protocol KeyboardCapable: KeyboardAnimatable {
    func keyboardWillShow(notification: NSNotification)
    func keyboardWillHide(notification: NSNotification)
}

extension KeyboardCapable where Self: UIViewController {
    func registerKeyboardNotifications() {
        NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name:UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name:UIKeyboardWillHideNotification, object: nil)
    }

    func unregisterKeyboardNotifications() {
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
    }
}

您已经注意到上述代码中有一个无关的KeyboardAnimatable关键字。这只是我们需要创建的下一个协议的名称:

import Foundation
import UIKit

protocol KeyboardAnimatable {

}

extension KeyboardAnimatable where Self: UIViewController {
    func performKeyboardShowFullViewAnimation(withKeyboardHeight height: CGFloat, andDuration duration: NSTimeInterval) {
        UIView.animateWithDuration(duration, animations: { () -> Void in
            self.view.frame = CGRectMake(view.frame.origin.x, -height, view.bounds.width, view.bounds.height)
            }, completion: nil)
    }

    func performKeyboardHideFullViewAnimation(withDuration duration: NSTimeInterval) {
        UIView.animateWithDuration(duration, animations: { () -> Void in
            self.view.frame = CGRectMake(view.frame.origin.x, 0.0, view.bounds.width, view.bounds.height)
            }, completion: nil)
    }
}

这个KeyboardAnimatable协议为所有符合它的UIViewController提供了两种方法,分别为整个视图上下设置动画。

好的,如果KeyboardCapable符合KeyboardAnimatable,则所有符合Keyboard Capable的UIViewController也符合KeyboaardAnimatable。这很酷。

让我们看看符合KeyboardCapable的UIViewController,并对键盘事件做出反应:

import Foundation
import UIKit

class TransferConfirmViewController: UIViewController, KeyboardCapable {
    //MARK: - LIFE CYCLE       
    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)

        registerKeyboardNotifications()
    }

    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)

        unregisterKeyboardNotifications()
    }

    //MARK: - NOTIFICATIONS
    //MARK: Keyboard
    func keyboardWillShow(notification: NSNotification) {
        let keyboardHeight = (notification.userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue().height
        let animationDuration = notification.userInfo![UIKeyboardAnimationDurationUserInfoKey] as! Double
        performKeyboardShowFullViewAnimation(withKeyboardHeight: keyboardHeight, andDuration: animationDuration)
    }

    func keyboardWillHide(notification: NSNotification) {
        let animationDuration = notification.userInfo![UIKeyboardAnimationDurationUserInfoKey] as! Double
        performKeyboardHideFullViewAnimation(withDuration: animationDuration)
    }
}

现在,您的UIViewController将响应键盘事件,并将因此产生动画效果。

注意:如果您想要自定义动画而不是推拉视图,则必须在KeyboardAnimatable协议上定义自定义方法或在Keyboard功能上执行这些方法。这取决于你。

非常轻量级的解决方案可以使用KeyboardAnimator。

项目获得了示例实现,文档编制仍在进行中。。。

适当用法:它具有UITextField和UITextView的特定实现

限制::它完全基于objective-c,swift版本将很快推出。

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];
}

您需要以编程方式添加具有特定帧大小的滚动视图。您必须在.h文件中添加UIScrollViewDelegate。您必须启用滚动视图,以便在viewDidLoad()中编写以下内容。

scrollview.scrollEnabled=YES;
scrollview.delegate=self;

scrollview.frame = CGRectMake(x,y,width,height);
//---set the content size of the scroll view--- 

[scrollview setContentSize:CGSizeMake(height,width)];

这样,可以添加x、y、宽度和高度值。