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
结合并填写几个答案(特别是Ortwin Gentz，用户98013)和另一篇文章中的空白，这将适用于iPad上的SDK 4.3的纵向或横向模式:
@implementation UIView (FindFirstResponder)
- (UIResponder *)findFirstResponder
{
if (self.isFirstResponder) {
return self;
}
for (UIView *subView in self.subviews) {
UIResponder *firstResponder = [subView findFirstResponder];
if (firstResponder != nil) {
return firstResponder;
}
}
return nil;
}
@end
@implementation MyViewController
- (UIResponder *)currentFirstResponder {
return [self.view findFirstResponder];
}
- (IBAction)editingEnded:sender {
[sender resignFirstResponder];
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
[textField resignFirstResponder];
return NO;
}
- (void)textFieldDidBeginEditing:(UITextField *)textField {
UITableViewCell *cell = (UITableViewCell*) [[textField superview] superview];
[_tableView scrollToRowAtIndexPath:[_tableView indexPathForCell:cell] atScrollPosition:UITableViewScrollPositionTop animated:YES];
}
- (void)keyboardWillShow:(NSNotification*)notification {
if ([self currentFirstResponder] != nil) {
NSDictionary* userInfo = [notification userInfo];
// we don't use SDK constants here to be universally compatible with all SDKs ≥ 3.0
NSValue* keyboardFrameValue = [userInfo objectForKey:@"UIKeyboardBoundsUserInfoKey"];
if (!keyboardFrameValue) {
keyboardFrameValue = [userInfo objectForKey:@"UIKeyboardFrameEndUserInfoKey"];
}
// Reduce the tableView height by the part of the keyboard that actually covers the tableView
CGRect windowRect = [[UIApplication sharedApplication] keyWindow].bounds;
CGRect viewRectAbsolute = [_tableView convertRect:_tableView.bounds toView:[[UIApplication sharedApplication] keyWindow]];
CGRect frame = _tableView.frame;
if (UIInterfaceOrientationLandscapeLeft == self.interfaceOrientation ||UIInterfaceOrientationLandscapeRight == self.interfaceOrientation ) {
windowRect = CGRectMake(windowRect.origin.y, windowRect.origin.x, windowRect.size.height, windowRect.size.width);
viewRectAbsolute = CGRectMake(viewRectAbsolute.origin.y, viewRectAbsolute.origin.x, viewRectAbsolute.size.height, viewRectAbsolute.size.width);
}
frame.size.height -= [keyboardFrameValue CGRectValue].size.height - CGRectGetMaxY(windowRect) + CGRectGetMaxY(viewRectAbsolute);
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
[UIView setAnimationCurve:[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
_tableView.frame = frame;
[UIView commitAnimations];
UITableViewCell *textFieldCell = (id)((UITextField *)self.currentFirstResponder).superview.superview;
NSIndexPath *textFieldIndexPath = [_tableView indexPathForCell:textFieldCell];
// iOS 3 sends hide and show notifications right after each other
// when switching between textFields, so cancel -scrollToOldPosition requests
[NSObject cancelPreviousPerformRequestsWithTarget:self];
_topmostRowBeforeKeyboardWasShown = [[_tableView indexPathsForVisibleRows] objectAtIndex:0];
[_tableView scrollToRowAtIndexPath:textFieldIndexPath atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
}
}
- (void) scrollToOldPosition {
[_tableView scrollToRowAtIndexPath:_topmostRowBeforeKeyboardWasShown atScrollPosition:UITableViewScrollPositionTop animated:YES];
}
- (void)keyboardWillHide:(NSNotification*)notification {
if ([self currentFirstResponder] != nil) {
NSDictionary* userInfo = [notification userInfo];
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
[UIView setAnimationCurve:[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
_tableView.frame = self.view.bounds;
[UIView commitAnimations];
[self performSelector:@selector(scrollToOldPosition) withObject:nil afterDelay:0.1];
}
}
@end
其他回答
Swift 4.2完整解决方案
我用一组协议创建了GIST，它简化了显示、隐藏或更改键盘时添加额外空间的工作。
特点:
正确使用键盘帧变化(例如，键盘高度变化，如emojii→普通键盘)。 标签栏和工具栏支持UITableView的例子(在其他例子你收到不正确的插入)。 动态动画持续时间(非硬编码)。 面向协议的方法，可以很容易地为您的目的进行修改。
使用
包含一些滚动视图(当然也支持表格视图)的视图控制器的基本用法示例。
class SomeViewController: UIViewController {
@IBOutlet weak var scrollView: UIScrollView!
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
addKeyboardFrameChangesObserver()
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
removeKeyboardFrameChangesObserver()
}
}
extension SomeViewController: ModifableInsetsOnKeyboardFrameChanges {
var scrollViewToModify: UIScrollView { return scrollView }
}
核心:帧改变观察者
协议KeyboardChangeFrameObserver将在每次键盘帧被改变时触发事件(包括显示，隐藏，帧改变)。
在viewWillAppear()或类似方法调用addKeyboardFrameChangesObserver()。 在viewWillDisappear()或类似的方法调用removeKeyboardFrameChangesObserver()。
实现:滚动视图
ModifableInsetsOnKeyboardFrameChanges协议将UIScrollView支持添加到核心协议。当键盘帧改变时，它改变滚动视图的嵌入。
你的类需要设置滚动视图，一个人的插入将增加/减少键盘帧的变化。
var scrollViewToModify: UIScrollView { get }
以下是我的解决方案，灵感来自iOS7日历应用程序的“事件编辑”屏幕。
该解决方案的关键之一是当用户滚动表格时键盘被取消。
实现:
1)添加属性，将存储选定的文本字段:
@property (strong) UITextField *currentTextField;
和BOOL变量，我们将使用它来检查当用户滚动表时是否需要隐藏键盘。
BOOL hideKeyboardOnScroll;
2)处理UITextField委托回调:
#pragma mark - UITextFieldDelegate
- (void) textFieldDidBeginEditing: (UITextField *) textField {
self.currentTextField = textField;
}
- (void) textFieldDidEndEditing: (UITextField *) textField {
self.currentTextField = nil;
}
- (BOOL) textFieldShouldReturn: (UITextField *) textField {
[textField resignFirstResponder];
CGPoint newContentOffset = CGPointZero;
if (tableView.contentSize.height > tableView.frame.size.height) {
newContentOffset.y = MIN(tableView.contentOffset.y, tableView.contentSize.height - tableView.frame.size.height);
}
[tableView setContentOffset: newContentOffset animated: YES];
return YES;
}
3)处理UIScrollViewDelegate方法来检查用户滚动视图。
#pragma mark - UIScrollViewDelegate
- (void) scrollViewDidScroll: (UIScrollView *) scrollView {
if (hideKeyboardOnScroll == YES) {
[self.currentTextField resignFirstResponder];
}
}
4)在视图控制器的[viewWillAppear]方法中订阅键盘通知，并在[viewWillDisappear]方法中取消订阅。
- (void) viewWillAppear: (BOOL) animated {
[super viewWillAppear: animated];
[ [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];
[ [NSNotificationCenter defaultCenter] removeObserver: self name: UIKeyboardDidShowNotification object: nil];
[ [NSNotificationCenter defaultCenter] removeObserver: self name: UIKeyboardWillHideNotification object: nil];
}
5)处理键盘通知:
- (void) keyboardWillShow: (NSNotification *) notification {
CGRect keyboardFrame = [ [ [notification userInfo] objectForKey: UIKeyboardFrameBeginUserInfoKey] CGRectValue];
// Find cell with textfield.
CGRect textFieldFrame = [tableView convertRect: self.currentTextField.frame fromView: self.currentTextField];
NSIndexPath *indexPath = [tableView indexPathForRowAtPoint: textFieldFrame.origin];
UITableViewCell *cell = [tableView cellForRowAtIndexPath: indexPath];
//
// Shrink tableView size.
CGRect tableViewFrame = tableView.frame;
tableView.frame = CGRectMake(tableView.frame.origin.x, tableView.frame.origin.y, tableView.frame.size.width,
self.view.frame.size.height - tableView.frame.origin.y - keyboardFrame.size.height);
//
// Check if cell is visible in shrinked table size.
BOOL cellIsFullyVisible = YES;
if ( cell.frame.origin.y < tableView.contentOffset.y ||
(cell.frame.origin.y + cell.frame.size.height) > (tableView.contentOffset.y + tableView.frame.size.height) ) {
cellIsFullyVisible = NO;
}
//
// If cell is not fully visible when scroll table to show cell;
if (cellIsFullyVisible == NO) {
CGPoint contentOffset = CGPointMake(tableView.contentOffset.x, CGRectGetMaxY(cell.frame) - tableView.frame.size.height);
if (cell.frame.origin.y < tableView.contentOffset.y) {
contentOffset.y = cell.frame.origin.y;
}
contentOffset.y = MAX(0, contentOffset.y);
// For some reason [setContentOffset] is called without delay then
// this code may not work for some cells. That why we call it with brief delay.
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC));
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
[UIView animateWithDuration: 0.5 animations:^{
[tableView setContentOffset: contentOffset animated: NO];
} completion: ^(BOOL finished) {
hideKeyboardOnScroll = YES;
}];
});
} else {
hideKeyboardOnScroll = YES;
}
//
// Finally restore original table frame.
tableView.frame = tableViewFrame;
//
}
- (void) keyboardWillHide: (NSNotification *) notification {
[super keyboardWillHide: notification];
hideKeyboardOnScroll = NO;
}
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()
}
}
}
结合并填写几个答案(特别是Ortwin Gentz，用户98013)和另一篇文章中的空白，这将适用于iPad上的SDK 4.3的纵向或横向模式:
@implementation UIView (FindFirstResponder)
- (UIResponder *)findFirstResponder
{
if (self.isFirstResponder) {
return self;
}
for (UIView *subView in self.subviews) {
UIResponder *firstResponder = [subView findFirstResponder];
if (firstResponder != nil) {
return firstResponder;
}
}
return nil;
}
@end
@implementation MyViewController
- (UIResponder *)currentFirstResponder {
return [self.view findFirstResponder];
}
- (IBAction)editingEnded:sender {
[sender resignFirstResponder];
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
[textField resignFirstResponder];
return NO;
}
- (void)textFieldDidBeginEditing:(UITextField *)textField {
UITableViewCell *cell = (UITableViewCell*) [[textField superview] superview];
[_tableView scrollToRowAtIndexPath:[_tableView indexPathForCell:cell] atScrollPosition:UITableViewScrollPositionTop animated:YES];
}
- (void)keyboardWillShow:(NSNotification*)notification {
if ([self currentFirstResponder] != nil) {
NSDictionary* userInfo = [notification userInfo];
// we don't use SDK constants here to be universally compatible with all SDKs ≥ 3.0
NSValue* keyboardFrameValue = [userInfo objectForKey:@"UIKeyboardBoundsUserInfoKey"];
if (!keyboardFrameValue) {
keyboardFrameValue = [userInfo objectForKey:@"UIKeyboardFrameEndUserInfoKey"];
}
// Reduce the tableView height by the part of the keyboard that actually covers the tableView
CGRect windowRect = [[UIApplication sharedApplication] keyWindow].bounds;
CGRect viewRectAbsolute = [_tableView convertRect:_tableView.bounds toView:[[UIApplication sharedApplication] keyWindow]];
CGRect frame = _tableView.frame;
if (UIInterfaceOrientationLandscapeLeft == self.interfaceOrientation ||UIInterfaceOrientationLandscapeRight == self.interfaceOrientation ) {
windowRect = CGRectMake(windowRect.origin.y, windowRect.origin.x, windowRect.size.height, windowRect.size.width);
viewRectAbsolute = CGRectMake(viewRectAbsolute.origin.y, viewRectAbsolute.origin.x, viewRectAbsolute.size.height, viewRectAbsolute.size.width);
}
frame.size.height -= [keyboardFrameValue CGRectValue].size.height - CGRectGetMaxY(windowRect) + CGRectGetMaxY(viewRectAbsolute);
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
[UIView setAnimationCurve:[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
_tableView.frame = frame;
[UIView commitAnimations];
UITableViewCell *textFieldCell = (id)((UITextField *)self.currentFirstResponder).superview.superview;
NSIndexPath *textFieldIndexPath = [_tableView indexPathForCell:textFieldCell];
// iOS 3 sends hide and show notifications right after each other
// when switching between textFields, so cancel -scrollToOldPosition requests
[NSObject cancelPreviousPerformRequestsWithTarget:self];
_topmostRowBeforeKeyboardWasShown = [[_tableView indexPathsForVisibleRows] objectAtIndex:0];
[_tableView scrollToRowAtIndexPath:textFieldIndexPath atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
}
}
- (void) scrollToOldPosition {
[_tableView scrollToRowAtIndexPath:_topmostRowBeforeKeyboardWasShown atScrollPosition:UITableViewScrollPositionTop animated:YES];
}
- (void)keyboardWillHide:(NSNotification*)notification {
if ([self currentFirstResponder] != nil) {
NSDictionary* userInfo = [notification userInfo];
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
[UIView setAnimationCurve:[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
_tableView.frame = self.view.bounds;
[UIView commitAnimations];
[self performSelector:@selector(scrollToOldPosition) withObject:nil afterDelay:0.1];
}
}
@end
我认为没有“正确”的方法来做这件事。您必须为您的用例选择最合适的解决方案。 在我的iPad App中，我有一个UIViewController，它以UIModalPresentationFormSheet的形式呈现，由一个UITableView组成。这个表格每个单元格包含两个UITextFields。 只是调用scrollToRowAtIndexPath:atScrollPosition:animated:在textFieldDidBeginEditing:方法不为我工作。因此，我创建了一个tableFooterView:
- (void)viewDidLoad
{
[super viewDidLoad];
m_footerView = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, m_tableView.frame.size.width, 300.0f)];
[m_footerView setBackgroundColor:[UIColor clearColor]];
[m_tableView setTableFooterView:m_footerView];
[m_footerView release];
}
这个想法是键盘隐藏tableFooterView而不是UITextFields。tableFooterView必须足够高。之后，你可以在textFieldDidBeginEditing:方法中使用scrollToRowAtIndexPath:atScrollPosition:animated:。
我认为也可以通过添加键盘通知的观察者来动态地显示和隐藏tableFooterView，但我还没有尝试过:
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillShow:)
name:UIKeyboardWillShowNotification
object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillHide:)
name:UIKeyboardWillHideNotification
object:nil];
}
- (void)keyboardWillShow:(NSNotification *)notification
{
[m_tableView setTableFooterView:m_footerView];
}
- (void)keyboardWillHide:(NSNotification *)notification
{
[m_tableView setTableFooterView:nil];
}
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}
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