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
我遇到了同样的问题,但注意到它只出现在一个视图中。所以我开始寻找不同的控制器。
我发现滚动行为设置在- (void)viewWillAppear:(BOOL)动画的超级实例。
所以一定要像这样实现:
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
// your code
}
不管你用的是UIViewController还是UITableViewController;通过将UITableView作为self的子视图来检查它。UIViewController中的视图。这是相同的行为。视图不允许滚动,如果调用[super viewWillAppear:animated];失踪了。
其他回答
因此,经过数小时的艰苦工作,尝试使用这些当前的解决方案(完全失败),我终于让事情正常工作,并更新它们以使用新的动画块。我的回答完全基于Ortwin上面的回答。
所以不管出于什么原因,上面的代码就是不适合我。我的设置似乎和其他人的很相似,但可能是因为我用的是iPad或4.3……不知道。它在做一些古怪的数学运算然后把我的tableview从屏幕上拍下来。
见我的解决方案的最终结果:http://screencast.com/t/hjBCuRrPC(请忽略照片。: - p)
所以我沿用了Ortwin的基本原理,但改变了计算原点的方法。Y和尺寸。我的表格视图的高度和键盘的高度。当我从结果中减去窗口的高度时,它告诉我有多少交集。如果它大于0(也就是有一些重叠),我执行帧高度的动画。
此外,还有一些重绘问题得到了解决,1)等待滚动到单元格直到动画完成,2)使用UIViewAnimationOptionBeginFromCurrentState选项隐藏键盘。
有几件事需要注意。
_topmostrowbeforekeyboardwasshow & _originalFrame是在头文件中声明的实例变量。 自我。guestEntryTableView是我的tableView(我在外部文件中) iaskcgrecswap是Ortwin用于翻转帧坐标的方法 我只更新tableView的高度如果它至少有50px会显示 因为我不在UIViewController中,所以我没有self。视图,我只是把tableView返回到它的原始框架
同样,如果我Ortwin没有提供关键,我也不会得到这个答案。代码如下:
- (IBAction)textFieldDidBeginEditing:(UITextField *)textField
{
self.activeTextField = textField;
if ([self.guestEntryTableView indexPathsForVisibleRows].count) {
_topmostRowBeforeKeyboardWasShown = (NSIndexPath*)[[self.guestEntryTableView indexPathsForVisibleRows] objectAtIndex:0];
} else {
// this should never happen
_topmostRowBeforeKeyboardWasShown = [NSIndexPath indexPathForRow:0 inSection:0];
[textField resignFirstResponder];
}
}
- (IBAction)textFieldDidEndEditing:(UITextField *)textField
{
self.activeTextField = nil;
}
- (void)keyboardWillShow:(NSNotification*)notification {
NSDictionary* userInfo = [notification userInfo];
NSValue* keyboardFrameValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
// Reduce the tableView height by the part of the keyboard that actually covers the tableView
UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
CGRect windowRect = [[UIApplication sharedApplication] keyWindow].bounds;
CGRect viewRectAbsolute = [self.guestEntryTableView convertRect:self.guestEntryTableView.bounds toView:[[UIApplication sharedApplication] keyWindow]];
CGRect keyboardFrame = [keyboardFrameValue CGRectValue];
if (UIInterfaceOrientationLandscapeLeft == orientation ||UIInterfaceOrientationLandscapeRight == orientation ) {
windowRect = IASKCGRectSwap(windowRect);
viewRectAbsolute = IASKCGRectSwap(viewRectAbsolute);
keyboardFrame = IASKCGRectSwap(keyboardFrame);
}
// fix the coordinates of our rect to have a top left origin 0,0
viewRectAbsolute = FixOriginRotation(viewRectAbsolute, orientation, windowRect.size.width, windowRect.size.height);
CGRect frame = self.guestEntryTableView.frame;
_originalFrame = self.guestEntryTableView.frame;
int remainder = (viewRectAbsolute.origin.y + viewRectAbsolute.size.height + keyboardFrame.size.height) - windowRect.size.height;
if (remainder > 0 && !(remainder > frame.size.height + 50)) {
frame.size.height = frame.size.height - remainder;
float duration = [[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
[UIView animateWithDuration: duration
animations:^{
self.guestEntryTableView.frame = frame;
}
completion:^(BOOL finished){
UITableViewCell *textFieldCell = (UITableViewCell*) [[self.activeTextField superview] superview];
NSIndexPath *textFieldIndexPath = [self.guestEntryTableView indexPathForCell:textFieldCell];
[self.guestEntryTableView scrollToRowAtIndexPath:textFieldIndexPath atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
}];
}
}
- (void)keyboardWillHide:(NSNotification*)notification {
NSDictionary* userInfo = [notification userInfo];
float duration = [[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
[UIView animateWithDuration: duration
delay: 0.0
options: (UIViewAnimationOptionBeginFromCurrentState)
animations:^{
self.guestEntryTableView.frame = _originalFrame;
}
completion:^(BOOL finished){
[self.guestEntryTableView scrollToRowAtIndexPath:_topmostRowBeforeKeyboardWasShown atScrollPosition:UITableViewScrollPositionTop animated:YES];
}];
}
#pragma mark CGRect Utility function
CGRect IASKCGRectSwap(CGRect rect) {
CGRect newRect;
newRect.origin.x = rect.origin.y;
newRect.origin.y = rect.origin.x;
newRect.size.width = rect.size.height;
newRect.size.height = rect.size.width;
return newRect;
}
CGRect FixOriginRotation(CGRect rect, UIInterfaceOrientation orientation, int parentWidth, int parentHeight) {
CGRect newRect;
switch(orientation)
{
case UIInterfaceOrientationLandscapeLeft:
newRect = CGRectMake(parentWidth - (rect.size.width + rect.origin.x), rect.origin.y, rect.size.width, rect.size.height);
break;
case UIInterfaceOrientationLandscapeRight:
newRect = CGRectMake(rect.origin.x, parentHeight - (rect.size.height + rect.origin.y), rect.size.width, rect.size.height);
break;
case UIInterfaceOrientationPortrait:
newRect = rect;
break;
case UIInterfaceOrientationPortraitUpsideDown:
newRect = CGRectMake(parentWidth - (rect.size.width + rect.origin.x), parentHeight - (rect.size.height + rect.origin.y), rect.size.width, rect.size.height);
break;
}
return newRect;
}
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()
}
}
}
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;
}
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;
}