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
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
我刚刚解决了这样一个问题,我参考了大量的解决方案通过谷歌和堆栈溢出。
首先,请确保你已经为UIScrollView设置了IBOutlet, 那么请仔细看看Apple Doc: Keyboard Management。 最后,如果你可以滚动背景,但键盘仍然覆盖文本字段,请看看这段代码:
// If active text field is hidden by keyboard, scroll it so it's visible
// Your application might not need or want this behavior.
CGRect aRect = self.view.frame;
aRect.size.height -= kbSize.height;
if (aRect.size.height < activeField.frame.origin.y+activeField.frame.size.height) {
CGPoint scrollPoint = CGPointMake(0.0, activeField.frame.origin.y+activeField.frame.size.height-aRect.size.height);
[scrollView setContentOffset:scrollPoint animated:YES];
这款游戏与苹果游戏的主要区别在于if条件。我认为apple计算滚动距离和键盘是否覆盖文本字段的条件不准确,所以我做了如上修改。
如果有用请告诉我
如果你使用UITableViewController而不是UIViewController,它会自动这样做。
这个解决方案为我工作,请注意这一行
[tableView setContentOffset:CGPointMake(0.0, activeField.frame.origin.y-kbSize.height+160) animated:YES];
您可以更改160值以使其与您的工作相匹配
- (void)keyboardWasShown:(NSNotification*)aNotification
{
NSDictionary* info = [aNotification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
CGRect bkgndRect = activeField.superview.frame;
bkgndRect.size.height += kbSize.height;
[activeField.superview setFrame:bkgndRect];
[tableView setContentOffset:CGPointMake(0.0, activeField.frame.origin.y-kbSize.height+160) animated:YES];
}
- (void)textFieldDidBeginEditing:(UITextField *)textField
{
activeField = textField;
}
-(void)textFieldDidEndEditing:(UITextField *)textField
{
activeField = nil;
}
// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
UIEdgeInsets contentInsets = UIEdgeInsetsZero;
tableView.contentInset = contentInsets;
tableView.scrollIndicatorInsets = contentInsets;
NSDictionary* info = [aNotification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
CGRect bkgndRect = activeField.superview.frame;
//bkgndRect.size.height += kbSize.height;
[activeField.superview setFrame:bkgndRect];
[tableView setContentOffset:CGPointMake(0.0, activeField.frame.origin.y-kbSize.height) animated:YES];
}
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。