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];
}
其他回答
我希望你们读了这些已经找到了答案。但我找到了我的解决方案如下。我期待你已经有一个单元与UITextField。在准备时,保持行索引到文本字段的标签中。
cell.textField.tag = IndexPath.row;
创建一个activeTextField, UITextField实例的全局作用域如下所示:
@interface EditViewController (){
UITextField *activeTextField;
}
现在你只需要在最后复制粘贴我的代码。别忘了添加UITextFieldDelegate
#pragma mark - TextField Delegation
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField{
activeTextField = textField;
return YES;
}
- (void)textFieldDidEndEditing:(UITextField *)textField{
activeTextField = nil;
}
注册键盘通知
#pragma mark - Keyboard Activity
- (void)registerForKeyboardNotifications
{
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWasShown:)
name:UIKeyboardDidShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillBeHidden:)
name:UIKeyboardWillHideNotification object:nil];
}
处理键盘通知:
当发送UIKeyboardDidShowNotification时调用。
- (void)keyboardWasShown:(NSNotification*)aNotification
{
NSDictionary* info = [aNotification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
[self.tableView setContentInset:contentInsets];
[self.tableView setScrollIndicatorInsets:contentInsets];
NSIndexPath *currentRowIndex = [NSIndexPath indexPathForRow:activeTextField.tag inSection:0];
[self.tableView scrollToRowAtIndexPath:currentRowIndex atScrollPosition:UITableViewScrollPositionTop animated:YES];
}
当UIKeyboardWillHideNotification被发送时调用
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
UIEdgeInsets contentInsets = UIEdgeInsetsZero;
[self.tableView setContentInset:contentInsets];
[self.tableView setScrollIndicatorInsets:contentInsets];
}
现在还剩下一件事,在ViewDidLoad方法中调用registerForKeyboardNotifications方法,如下所示:
- (void)viewDidLoad {
[super viewDidLoad];
// Registering keyboard notification
[self registerForKeyboardNotifications];
// Your codes here...
}
你完成了,希望你的文本字段将不再隐藏在键盘。
我将把我的解决方案(或者QuickDialog的)扔进帽子里。基本上是等待动画到滚动。获得键盘动画JIT而不是神奇的数字会很好。
-(void)textFieldDidBeginEditing:(UITextField *)textField
{
if (textField == self.emailTextField) {
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, 50 * USEC_PER_SEC);
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
[self.tableView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionTop animated:YES];
});
}
}
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;
}
在viewdidload
-(void)viewdidload{
[super viewdidload];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillChange:) name:UIKeyboardWillChangeFrameNotification object:nil];
}
-(void)keyboardWillChange:(NSNotification*)sender{
NSLog(@"keyboardwillchange sender %@",sender);
float margin=0 // set your own topmargin
CGFloat originY = [[sender.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].origin.y;
if (originY >= self.view.frame.size.height){
NSLog(@"keyboardclose");
[tb_ setFrame:CGRectMake(0, margin, self.view.frame.size.width, self.view.frame.size.height-margin)];
}else{
NSLog(@"keyobard on");
float adjustedHeight = self.view.frame.size.height - margin - (self.view.frame.size.height-originY);
[tb_ setFrame:CGRectMake(0, margin, self.view.frame.size.width, adjustedHeight)];
}
}
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