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。
这是使用Swift的解决方案。
import UIKit
class ExampleViewController: UIViewController, UITextFieldDelegate {
@IBOutlet var scrollView: UIScrollView!
@IBOutlet var textField1: UITextField!
@IBOutlet var textField2: UITextField!
@IBOutlet var textField3: UITextField!
@IBOutlet var textField4: UITextField!
@IBOutlet var textField5: UITextField!
var activeTextField: UITextField!
// MARK: - View
override func viewDidLoad() {
super.viewDidLoad()
self.textField1.delegate = self
self.textField2.delegate = self
self.textField3.delegate = self
self.textField4.delegate = self
self.textField5.delegate = self
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
self.registerForKeyboardNotifications()
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
self.unregisterFromKeyboardNotifications()
}
// MARK: - Keyboard
// Call this method somewhere in your view controller setup code.
func registerForKeyboardNotifications() {
let center: NSNotificationCenter = NSNotificationCenter.defaultCenter()
center.addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardDidShowNotification, object: nil)
center.addObserver(self, selector: "keyboardWillBeHidden:", name: UIKeyboardWillHideNotification, object: nil)
}
func unregisterFromKeyboardNotifications () {
let center: NSNotificationCenter = NSNotificationCenter.defaultCenter()
center.removeObserver(self, name: UIKeyboardDidShowNotification, object: nil)
center.removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
}
// Called when the UIKeyboardDidShowNotification is sent.
func keyboardWasShown (notification: NSNotification) {
let info : NSDictionary = notification.userInfo!
let kbSize = (info.objectForKey(UIKeyboardFrameBeginUserInfoKey)?.CGRectValue() as CGRect!).size
let contentInsets: UIEdgeInsets = 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.
var aRect = self.view.frame
aRect.size.height -= kbSize.height;
if (!CGRectContainsPoint(aRect, self.activeTextField.frame.origin) ) {
self.scrollView.scrollRectToVisible(self.activeTextField.frame, animated: true)
}
}
// Called when the UIKeyboardWillHideNotification is sent
func keyboardWillBeHidden (notification: NSNotification) {
let contentInsets = UIEdgeInsetsZero;
scrollView.contentInset = contentInsets;
scrollView.scrollIndicatorInsets = contentInsets;
}
// MARK: - Text Field
func textFieldDidBeginEditing(textField: UITextField) {
self.activeTextField = textField
}
func textFieldDidEndEditing(textField: UITextField) {
self.activeTextField = nil
}
}
这是我为特定布局想出的破解方案。此解决方案与Matt Gallagher的解决方案相似，即将一个部分滚动到视图中。我还是iPhone开发的新手，不熟悉布局的工作原理。因此，这个黑客。
我的实现需要支持在字段中单击时滚动，以及用户在键盘上选择下一个时滚动。
我有一个UIView，身高775。控件基本上以3人一组的方式分布在一个大的空间中。我最终得到了以下IB布局。
UIView -> UIScrollView -> [UI Components]
黑客来了
我将UIScrollView的高度设置为比实际布局（1250）大500个单位。然后，我创建了一个数组，其中包含我需要滚动到的绝对位置，以及一个基于IB标记号获取它们的简单函数。
static NSInteger stepRange[] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 140, 140, 140, 140, 140, 410
};
NSInteger getScrollPos(NSInteger i) {
if (i < TXT_FIELD_INDEX_MIN || i > TXT_FIELD_INDEX_MAX) {
return 0 ;
return stepRange[i] ;
}
现在，您需要做的就是在textFieldDidBeginEditing和textFieldShouldReturn中使用以下两行代码（如果要创建下一个字段导航，则使用后者）
CGPoint point = CGPointMake(0, getScrollPos(textField.tag)) ;
[self.scrollView setContentOffset:point animated:YES] ;
一个例子。
- (void) textFieldDidBeginEditing:(UITextField *)textField
{
CGPoint point = CGPointMake(0, getScrollPos(textField.tag)) ;
[self.scrollView setContentOffset:point animated:YES] ;
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
NSInteger nextTag = textField.tag + 1;
UIResponder* nextResponder = [textField.superview viewWithTag:nextTag];
if (nextResponder) {
[nextResponder becomeFirstResponder];
CGPoint point = CGPointMake(0, getScrollPos(nextTag)) ;
[self.scrollView setContentOffset:point animated:YES] ;
}
else{
[textField resignFirstResponder];
}
return YES ;
}
此方法不像其他方法那样“向后滚动”。这不是必需的。同样，这是一个相当“高大”的UIView，我没有时间学习内部布局引擎。
如果文本字段未完全或部分隐藏，则我们不应更改任何内容。我们应该计算隐藏的精确相交区域（键盘的框架和文本字段的框架），然后我们应该更改视图的框架。这里我给出了一个完整的例子。声明3个变量
#定义衬垫10@接口PKViewController（）@属性（非原子，赋值）CGRect-originalViewFrame//原始视图的框架@属性（非原子，强）UITextField*activeTextField；//当前文本字段@属性（非原子，赋值）CGRect keyBoardRect；//安全板覆盖面积@完
存储原始帧
- (void)viewDidLoad {
[super viewDidLoad];
_originalViewFrame = self.view.frame;
}
将视图控制器添加为键盘通知的观察者
- (void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWasShown:)
name:UIKeyboardDidShowNotification
object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillHide:)
name:UIKeyboardWillHideNotification
object:nil];
}
移除观察者
- (void)viewWillDisappear:(BOOL)animated{
[super viewWillDisappear:animated];
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
当键盘出现时存储键盘覆盖的区域，当键盘消失时将其设置为CGRectZero
- (void)keyboardWasShown:(NSNotification *)notification{
CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
_keyBoardRect = CGRectMake(0, _originalViewFrame.size.height - keyboardSize.height, keyboardSize.width, keyboardSize.height);
[self moveTextFieldUP];
}
- (void) keyboardWillHide:(NSNotification *)notification{
_keyBoardRect = CGRectZero;
[self setDefaultFrame];
}
存储活动文本字段
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {
_activeTextField = textField;
//When keyboard is already present but the textfield is hidden. Case:When return key of keyboard makes the next textfield as first responder
if (!CGRectIsEmpty(_keyBoardRect)) {
[self moveTextFieldUP];
}
return YES;
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField{
[textField resignFirstResponder];
return YES;
}
现在我们应该改变视图的框架
- (void)moveTextFieldUP{
CGRect virtualTextFieldRect = CGRectMake(0, self.view.frame.origin.y, _activeTextField.frame.size.width, _activeTextField.frame.origin.y+_activeTextField.frame.size.height);
if (CGRectIntersectsRect(_keyBoardRect, virtualTextFieldRect)) {
CGRect intersectRect = CGRectIntersection(_keyBoardRect, virtualTextFieldRect);
CGFloat newY = _originalViewFrame.origin.y - intersectRect.size.height;
CGFloat newHeight = _originalViewFrame.size.height + intersectRect.size.height;
CGRect newFrame = CGRectMake(0, newY-PADDING, _originalViewFrame.size.width, newHeight+PADDING);
[UIView animateWithDuration:0.3 animations:^{
[self.view setFrame:newFrame];
}];
NSLog(@"Intersect");
}
}
- (void)setDefaultFrame {
[UIView animateWithDuration:0.3 animations:^{
[self.view setFrame:_originalViewFrame];
}];
}
