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
我的方法:
我首先子类化UITextField并添加一个indexPath属性。在牢房里因为…方法我交出indexPath属性。
然后我添加以下代码:
UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:textField.indexPath];
CGPoint cellPoint = [cell convertPoint:textField.center toView:self.tableView];
[UIView animateWithDuration:0.3 animations:^(void){self.tableView.contentOffset = CGPointMake(0, cellPoint.y-50);}];
textFieldShould/WillBegin…等等。
当键盘消失时，你必须反转它:
[UIView animateWithDuration:0.3 animations:^(void){self.tableView.contentOffset = CGPointMake(0, 0);}];
其他回答
我想我已经想出了与苹果应用程序行为相匹配的解决方案。
首先，在viewWillAppear:订阅键盘通知，这样你就知道什么时候键盘会显示和隐藏，系统会告诉你键盘的大小，但不要忘记在viewWillDisappear:中取消注册。
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:@selector(keyboardWillShow:)
name:UIKeyboardWillShowNotification
object:nil];
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:@selector(keyboardWillHide:)
name:UIKeyboardWillHideNotification
object:nil];
实现类似于下面的方法，以便在键盘显示时调整tableView的大小以匹配可见区域。这里我单独跟踪键盘的状态，所以我可以自己选择何时将tableView设置为全高度，因为你在每个字段更改时都会收到这些通知。不要忘记实现keyboardWillHide:并选择适当的地方来修复你的tableView大小。
-(void) keyboardWillShow:(NSNotification *)note
{
CGRect keyboardBounds;
[[note.userInfo valueForKey:UIKeyboardBoundsUserInfoKey] getValue: &keyboardBounds];
keyboardHeight = keyboardBounds.size.height;
if (keyboardIsShowing == NO)
{
keyboardIsShowing = YES;
CGRect frame = self.view.frame;
frame.size.height -= keyboardHeight;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:0.3f];
self.view.frame = frame;
[UIView commitAnimations];
}
}
现在这是滚动位，我们先计算出一些大小，然后我们看到我们在可见区域中的位置，并设置我们想要滚动的矩形，根据它在视图中的位置，将它设置为文本字段中间上方或下方的半视图。在本例中，我们有一个UITextFields数组和一个用于跟踪它们的enum，因此用rowHeight乘以行号就得到了这个外部视图中帧的实际偏移量。
- (void) textFieldDidBeginEditing:(UITextField *)textField
{
CGRect frame = textField.frame;
CGFloat rowHeight = self.tableView.rowHeight;
if (textField == textFields[CELL_FIELD_ONE])
{
frame.origin.y += rowHeight * CELL_FIELD_ONE;
}
else if (textField == textFields[CELL_FIELD_TWO])
{
frame.origin.y += rowHeight * CELL_FIELD_TWO;
}
else if (textField == textFields[CELL_FIELD_THREE])
{
frame.origin.y += rowHeight * CELL_FIELD_THREE;
}
else if (textField == textFields[CELL_FIELD_FOUR])
{
frame.origin.y += rowHeight * CELL_FIELD_FOUR;
}
CGFloat viewHeight = self.tableView.frame.size.height;
CGFloat halfHeight = viewHeight / 2;
CGFloat midpoint = frame.origin.y + (textField.frame.size.height / 2);
if (midpoint < halfHeight)
{
frame.origin.y = 0;
frame.size.height = midpoint;
}
else
{
frame.origin.y = midpoint;
frame.size.height = midpoint;
}
[self.tableView scrollRectToVisible:frame animated:YES];
}
这似乎工作得很好。
Swift最简单的解决方案:
override func viewDidLoad() {
super.viewDidLoad()
searchBar?.becomeFirstResponder()
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(MyViewController.keyboardWillShow(_:)), name: UIKeyboardDidShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(MyViewController.keyboardWillHide(_:)), name: UIKeyboardDidHideNotification, object: nil)
}
deinit {
NSNotificationCenter.defaultCenter().removeObserver(self)
}
func keyboardWillShow(notification: NSNotification) {
if let userInfo = notification.userInfo {
if let keyboardHeight = userInfo[UIKeyboardFrameEndUserInfoKey]?.CGRectValue.size.height {
tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardHeight, 0)
}
}
}
func keyboardWillHide(notification: NSNotification) {
UIView.animateWithDuration(0.2, animations: { self.table_create_issue.contentInset = UIEdgeInsetsMake(0, 0, 0, 0) })
// For some reason adding inset in keyboardWillShow is animated by itself but removing is not, that's why we have to use animateWithDuration here
}
Swift 4.2或更高版本
override func viewDidLoad() {
super.viewDidLoad()
searchBar?.becomeFirstResponder()
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: UIResponder.keyboardDidShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: UIResponder.keyboardDidHideNotification, object: nil)
}
deinit {
NotificationCenter.default.removeObserver(self)
}
@objc func keyboardWillShow(notification: NSNotification) {
if let userInfo = notification.userInfo {
let keyboardHeight = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as AnyObject).cgRectValue.size.height
accountSettingsTableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardHeight, right: 0)
}
}
@objc func keyboardWillHide(notification: NSNotification) {
UIView.animate(withDuration: 0.2, animations: { self.accountSettingsTableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0) })}
}
这非常有效，在iPad上也是如此。
- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
if(textField == textfield1){
[accountName1TextField becomeFirstResponder];
}else if(textField == textfield2){
[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
[textfield3 becomeFirstResponder];
}else if(textField == textfield3){
[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:1 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
[textfield4 becomeFirstResponder];
}else if(textField == textfield4){
[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:2 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
[textfield5 becomeFirstResponder];
}else if(textField == textfield5){
[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:3 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
[textfield6 becomeFirstResponder];
}else if(textField == textfield6){
[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:4 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
[textfield7 becomeFirstResponder];
}else if(textField == textfield7){
[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:5 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
[textfield8 becomeFirstResponder];
}else if(textField == textfield8){
[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:6 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
[textfield9 becomeFirstResponder];
}else if(textField == textfield9){
[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:7 inSection:1] atScrollPosition:UITableViewScrollPositionTop animated:YES];
[textField resignFirstResponder];
}
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)];
}
}
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