经过大量的试验和错误，我放弃了，并提出了这个问题。我见过很多人有类似的问题，但不能得到所有的答案工作正确。
我有一个由自定义单元格组成的UITableView。单元格由相邻的5个文本字段组成(有点像网格)。
当我试图滚动和编辑UITableView底部的单元格时，我不能设法让我的单元格正确地定位在键盘上方。
我看到过很多关于改变视图大小的回答……但到目前为止，没有一种效果很好。
谁能用一个具体的代码示例来阐明这样做的“正确”方式?
当前回答
Swift 3-4动画和键盘帧改变的解决方案:
首先，创建Bool类型:
// MARK: - Private Properties
private var isKeyboardShowing = false
其次，在系统键盘通知中添加观察者:
// MARK: - Overriding ViewController Life Cycle Methods
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: .UIKeyboardWillHide, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChangeFrame), name: .UIKeyboardWillChangeFrame, object: nil)
}
第三，准备动画功能:
func adjustTableViewInsets(keyboardHeight: CGFloat, duration: NSNumber, curve: NSNumber){
var extraHeight: CGFloat = 0
if keyboardHeight > 0 {
extraHeight = 20
isKeyboardShowing = true
} else {
isKeyboardShowing = false
}
let contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardHeight + extraHeight, right: 0)
func animateFunc() {
//refresh constraints
//self.view.layoutSubviews()
tableView.contentInset = contentInset
}
UIView.animate(withDuration: TimeInterval(duration), delay: 0, options: [UIViewAnimationOptions(rawValue: UInt(curve))], animations: animateFunc, completion: nil)
}
然后添加target/action方法(由观察者调用):
// MARK: - Target/Selector Actions
func keyboardWillShow(notification: NSNotification) {
if !isKeyboardShowing {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
let keyboardHeight = keyboardSize.height
let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber
adjustTableViewInsets(keyboardHeight: keyboardHeight, duration: duration, curve: curve)
}
}
}
func keyboardWillHide(notification: NSNotification) {
let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber
adjustTableViewInsets(keyboardHeight: 0, duration: duration, curve: curve)
}
func keyboardWillChangeFrame(notification: NSNotification) {
if isKeyboardShowing {
let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber
if let newKeyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
let keyboardHeight = newKeyboardSize.height
adjustTableViewInsets(keyboardHeight: keyboardHeight, duration: duration, curve: curve)
}
}
}
最后，不要忘记在deinit或viewWillDisappear中删除观察者:
deinit {
NotificationCenter.default.removeObserver(self)
}
其他回答
如果你使用Three20，那么使用autoresizesForKeyboard属性。只要在视图控制器的-initWithNibName:bundle方法中设置
self.autoresizesForKeyboard = YES
这涉及到:
监听键盘通知并调整表视图的框架 滚动到第一个响应器
搞定了。
因为你在一个表格中有文本字段，最好的方法是调整表格的大小——你需要设置tableView.frame的高度比键盘的大小小(我认为大约165像素)，然后当键盘被关闭时再次展开它。
如果你不想让用户滚动，你也可以选择在那个时候禁用tableView的用户交互。
Swift 3-4动画和键盘帧改变的解决方案:
首先，创建Bool类型:
// MARK: - Private Properties
private var isKeyboardShowing = false
其次，在系统键盘通知中添加观察者:
// MARK: - Overriding ViewController Life Cycle Methods
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: .UIKeyboardWillHide, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChangeFrame), name: .UIKeyboardWillChangeFrame, object: nil)
}
第三，准备动画功能:
func adjustTableViewInsets(keyboardHeight: CGFloat, duration: NSNumber, curve: NSNumber){
var extraHeight: CGFloat = 0
if keyboardHeight > 0 {
extraHeight = 20
isKeyboardShowing = true
} else {
isKeyboardShowing = false
}
let contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardHeight + extraHeight, right: 0)
func animateFunc() {
//refresh constraints
//self.view.layoutSubviews()
tableView.contentInset = contentInset
}
UIView.animate(withDuration: TimeInterval(duration), delay: 0, options: [UIViewAnimationOptions(rawValue: UInt(curve))], animations: animateFunc, completion: nil)
}
然后添加target/action方法(由观察者调用):
// MARK: - Target/Selector Actions
func keyboardWillShow(notification: NSNotification) {
if !isKeyboardShowing {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
let keyboardHeight = keyboardSize.height
let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber
adjustTableViewInsets(keyboardHeight: keyboardHeight, duration: duration, curve: curve)
}
}
}
func keyboardWillHide(notification: NSNotification) {
let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber
adjustTableViewInsets(keyboardHeight: 0, duration: duration, curve: curve)
}
func keyboardWillChangeFrame(notification: NSNotification) {
if isKeyboardShowing {
let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber
if let newKeyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
let keyboardHeight = newKeyboardSize.height
adjustTableViewInsets(keyboardHeight: keyboardHeight, duration: duration, curve: curve)
}
}
}
最后，不要忘记在deinit或viewWillDisappear中删除观察者:
deinit {
NotificationCenter.default.removeObserver(self)
}
我想我已经想出了与苹果应用程序行为相匹配的解决方案。
首先，在viewWillAppear:订阅键盘通知，这样你就知道什么时候键盘会显示和隐藏，系统会告诉你键盘的大小，但不要忘记在viewWillDisappear:中取消注册。
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:@selector(keyboardWillShow:)
name:UIKeyboardWillShowNotification
object:nil];
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:@selector(keyboardWillHide:)
name:UIKeyboardWillHideNotification
object:nil];
实现类似于下面的方法，以便在键盘显示时调整tableView的大小以匹配可见区域。这里我单独跟踪键盘的状态，所以我可以自己选择何时将tableView设置为全高度，因为你在每个字段更改时都会收到这些通知。不要忘记实现keyboardWillHide:并选择适当的地方来修复你的tableView大小。
-(void) keyboardWillShow:(NSNotification *)note
{
CGRect keyboardBounds;
[[note.userInfo valueForKey:UIKeyboardBoundsUserInfoKey] getValue: &keyboardBounds];
keyboardHeight = keyboardBounds.size.height;
if (keyboardIsShowing == NO)
{
keyboardIsShowing = YES;
CGRect frame = self.view.frame;
frame.size.height -= keyboardHeight;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:0.3f];
self.view.frame = frame;
[UIView commitAnimations];
}
}
现在这是滚动位，我们先计算出一些大小，然后我们看到我们在可见区域中的位置，并设置我们想要滚动的矩形，根据它在视图中的位置，将它设置为文本字段中间上方或下方的半视图。在本例中，我们有一个UITextFields数组和一个用于跟踪它们的enum，因此用rowHeight乘以行号就得到了这个外部视图中帧的实际偏移量。
- (void) textFieldDidBeginEditing:(UITextField *)textField
{
CGRect frame = textField.frame;
CGFloat rowHeight = self.tableView.rowHeight;
if (textField == textFields[CELL_FIELD_ONE])
{
frame.origin.y += rowHeight * CELL_FIELD_ONE;
}
else if (textField == textFields[CELL_FIELD_TWO])
{
frame.origin.y += rowHeight * CELL_FIELD_TWO;
}
else if (textField == textFields[CELL_FIELD_THREE])
{
frame.origin.y += rowHeight * CELL_FIELD_THREE;
}
else if (textField == textFields[CELL_FIELD_FOUR])
{
frame.origin.y += rowHeight * CELL_FIELD_FOUR;
}
CGFloat viewHeight = self.tableView.frame.size.height;
CGFloat halfHeight = viewHeight / 2;
CGFloat midpoint = frame.origin.y + (textField.frame.size.height / 2);
if (midpoint < halfHeight)
{
frame.origin.y = 0;
frame.size.height = midpoint;
}
else
{
frame.origin.y = midpoint;
frame.size.height = midpoint;
}
[self.tableView scrollRectToVisible:frame animated:YES];
}
这似乎工作得很好。
我在做一些非常相似的事情它是通用的，不需要为你的代码计算特定的东西。 只需检查代码上的注释:
在MyUIViewController.h
@interface MyUIViewController: UIViewController <UITableViewDelegate, UITableViewDataSource>
{
UITableView *myTableView;
UITextField *actifText;
}
@property (nonatomic, retain) IBOutlet UITableView *myTableView;
@property (nonatomic, retain) IBOutlet UITextField *actifText;
- (IBAction)textFieldDidBeginEditing:(UITextField *)textField;
- (IBAction)textFieldDidEndEditing:(UITextField *)textField;
-(void) keyboardWillHide:(NSNotification *)note;
-(void) keyboardWillShow:(NSNotification *)note;
@end
在MyUIViewController.m
@implementation MyUIViewController
@synthesize myTableView;
@synthesize actifText;
- (void)viewDidLoad
{
// Register notification when the keyboard will be show
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillShow:)
name:UIKeyboardWillShowNotification
object:nil];
// Register notification when the keyboard will be hide
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillHide:)
name:UIKeyboardWillHideNotification
object:nil];
}
// To be link with your TextField event "Editing Did Begin"
// memoryze the current TextField
- (IBAction)textFieldDidBeginEditing:(UITextField *)textField
{
self.actifText = textField;
}
// To be link with your TextField event "Editing Did End"
// release current TextField
- (IBAction)textFieldDidEndEditing:(UITextField *)textField
{
self.actifText = nil;
}
-(void) keyboardWillShow:(NSNotification *)note
{
// Get the keyboard size
CGRect keyboardBounds;
[[note.userInfo valueForKey:UIKeyboardFrameBeginUserInfoKey] getValue: &keyboardBounds];
// Detect orientation
UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
CGRect frame = self.myTableView.frame;
// Start animation
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:0.3f];
// Reduce size of the Table view
if (orientation == UIInterfaceOrientationPortrait || orientation == UIInterfaceOrientationPortraitUpsideDown)
frame.size.height -= keyboardBounds.size.height;
else
frame.size.height -= keyboardBounds.size.width;
// Apply new size of table view
self.myTableView.frame = frame;
// Scroll the table view to see the TextField just above the keyboard
if (self.actifText)
{
CGRect textFieldRect = [self.myTableView convertRect:self.actifText.bounds fromView:self.actifText];
[self.myTableView scrollRectToVisible:textFieldRect animated:NO];
}
[UIView commitAnimations];
}
-(void) keyboardWillHide:(NSNotification *)note
{
// Get the keyboard size
CGRect keyboardBounds;
[[note.userInfo valueForKey:UIKeyboardFrameBeginUserInfoKey] getValue: &keyboardBounds];
// Detect orientation
UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
CGRect frame = self.myTableView.frame;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:0.3f];
// Increase size of the Table view
if (orientation == UIInterfaceOrientationPortrait || orientation == UIInterfaceOrientationPortraitUpsideDown)
frame.size.height += keyboardBounds.size.height;
else
frame.size.height += keyboardBounds.size.width;
// Apply new size of table view
self.myTableView.frame = frame;
[UIView commitAnimations];
}
@end
Swift 1.2+版本:
class ViewController: UIViewController, UITextFieldDelegate {
@IBOutlet weak var activeText: UITextField!
@IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
NSNotificationCenter.defaultCenter().addObserver(self,
selector: Selector("keyboardWillShow:"),
name: UIKeyboardWillShowNotification,
object: nil)
NSNotificationCenter.defaultCenter().addObserver(self,
selector: Selector("keyboardWillHide:"),
name: UIKeyboardWillHideNotification,
object: nil)
}
func textFieldDidBeginEditing(textField: UITextField) {
activeText = textField
}
func textFieldDidEndEditing(textField: UITextField) {
activeText = nil
}
func keyboardWillShow(note: NSNotification) {
if let keyboardSize = (note.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
var frame = tableView.frame
UIView.beginAnimations(nil, context: nil)
UIView.setAnimationBeginsFromCurrentState(true)
UIView.setAnimationDuration(0.3)
frame.size.height -= keyboardSize.height
tableView.frame = frame
if activeText != nil {
let rect = tableView.convertRect(activeText.bounds, fromView: activeText)
tableView.scrollRectToVisible(rect, animated: false)
}
UIView.commitAnimations()
}
}
func keyboardWillHide(note: NSNotification) {
if let keyboardSize = (note.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
var frame = tableView.frame
UIView.beginAnimations(nil, context: nil)
UIView.setAnimationBeginsFromCurrentState(true)
UIView.setAnimationDuration(0.3)
frame.size.height += keyboardSize.height
tableView.frame = frame
UIView.commitAnimations()
}
}
}
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