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?
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
键盘通知可以工作,但苹果的示例代码假设滚动视图是窗口的根视图。通常情况并非如此。您必须补偿标签栏等,以获得正确的偏移量。
这比听起来容易。下面是我在UITableViewController中使用的代码。它有两个实例变量,hiddenRect和keyboardshow。
// Called when the UIKeyboardDidShowNotification is sent.
- (void)keyboardWasShown:(NSNotification*)aNotification {
if (keyboardShown)
return;
NSDictionary* info = [aNotification userInfo];
// Get the frame of the keyboard.
NSValue *centerValue = [info objectForKey:UIKeyboardCenterEndUserInfoKey];
NSValue *boundsValue = [info objectForKey:UIKeyboardBoundsUserInfoKey];
CGPoint keyboardCenter = [centerValue CGPointValue];
CGRect keyboardBounds = [boundsValue CGRectValue];
CGPoint keyboardOrigin = CGPointMake(keyboardCenter.x - keyboardBounds.size.width / 2.0,
keyboardCenter.y - keyboardBounds.size.height / 2.0);
CGRect keyboardScreenFrame = { keyboardOrigin, keyboardBounds.size };
// Resize the scroll view.
UIScrollView *scrollView = (UIScrollView *) self.tableView;
CGRect viewFrame = scrollView.frame;
CGRect keyboardFrame = [scrollView.superview convertRect:keyboardScreenFrame fromView:nil];
hiddenRect = CGRectIntersection(viewFrame, keyboardFrame);
CGRect remainder, slice;
CGRectDivide(viewFrame, &slice, &remainder, CGRectGetHeight(hiddenRect), CGRectMaxYEdge);
scrollView.frame = remainder;
// Scroll the active text field into view.
CGRect textFieldRect = [/* selected cell */ frame];
[scrollView scrollRectToVisible:textFieldRect animated:YES];
keyboardShown = YES;
}
// Called when the UIKeyboardDidHideNotification is sent
- (void)keyboardWasHidden:(NSNotification*)aNotification
{
// Reset the height of the scroll view to its original value
UIScrollView *scrollView = (UIScrollView *) self.tableView;
CGRect viewFrame = [scrollView frame];
scrollView.frame = CGRectUnion(viewFrame, hiddenRect);
keyboardShown = NO;
}
其他回答
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
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 }
一个更加流线型的解决方案。它滑入UITextField委托方法,所以它不需要搞砸/ UIKeyboard通知。
实现注意事项:
kSettingsRowHeight——UITableViewCell的高度。
offsetTarget和offsetThreshold基于kSettingsRowHeight。如果使用不同的行高,则将这些值设置为point的y属性。[alt:以不同的方式计算行偏移量。]
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {
CGFloat offsetTarget = 113.0f; // 3rd row
CGFloat offsetThreshold = 248.0f; // 6th row (i.e. 2nd-to-last row)
CGPoint point = [self.tableView convertPoint:CGPointZero fromView:textField];
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.2];
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
CGRect frame = self.tableView.frame;
if (point.y > offsetThreshold) {
self.tableView.frame = CGRectMake(0.0f,
offsetTarget - point.y + kSettingsRowHeight,
frame.size.width,
frame.size.height);
} else if (point.y > offsetTarget) {
self.tableView.frame = CGRectMake(0.0f,
offsetTarget - point.y,
frame.size.width,
frame.size.height);
} else {
self.tableView.frame = CGRectMake(0.0f,
0.0f,
frame.size.width,
frame.size.height);
}
[UIView commitAnimations];
return YES;
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
[textField resignFirstResponder];
[UIView beginAnimations:nil context:nil];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:0.2];
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
CGRect frame = self.tableView.frame;
self.tableView.frame = CGRectMake(0.0f,
0.0f,
frame.size.width,
frame.size.height);
[UIView commitAnimations];
return YES;
}
另一个简单的方法(只适用于一个部分)
//cellForRowAtIndexPath
UItextField *tf;
[cell addSubview:tf];
tf.tag = indexPath.row;
tf.delegate = self;
//textFieldDidBeginEditing:(UITextField *)text
[[self.tableView scrollToRowsAtIndexPath:[NSIndexPath indexPathForRow:text.tag in section:SECTIONINTEGER] animated:YES];