通用 UITableView 键盘调整大小算法

我搜索了很多调整表视图大小以适应键盘显示和隐藏的代码，但我遇到的几乎每一篇文章都假设表视图正在获取其视图控制器的整个视图。我有一个 iPad 应用程序，其中表格视图仅占据屏幕的一部分。在这种情况下调整表视图大小的正确方法是什么？ （我上面提到的帖子中的所有代码都失败了）

以下代码可以满足您的需求，并且适用于任何设备和任何布局。该代码是由明智的TableView框架（经许可复制和使用）。

- (void)keyboardWillShow:(NSNotification *)aNotification
{
if(keyboardShown) 
    return;

keyboardShown = YES;

// Get the keyboard size
UIScrollView *tableView;
if([self.tableView.superview isKindOfClass:[UIScrollView class]])
    tableView = (UIScrollView *)self.tableView.superview;
else
    tableView = self.tableView;
NSDictionary *userInfo = [aNotification userInfo];
NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
CGRect keyboardRect = [tableView.superview convertRect:[aValue CGRectValue] fromView:nil];

// Get the keyboard's animation details
NSTimeInterval animationDuration;
[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] getValue:&animationDuration];
UIViewAnimationCurve animationCurve;
[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] getValue:&animationCurve];

// Determine how much overlap exists between tableView and the keyboard
CGRect tableFrame = tableView.frame;
CGFloat tableLowerYCoord = tableFrame.origin.y + tableFrame.size.height;
keyboardOverlap = tableLowerYCoord - keyboardRect.origin.y;
if(self.inputAccessoryView && keyboardOverlap>0)
{
    CGFloat accessoryHeight = self.inputAccessoryView.frame.size.height;
    keyboardOverlap -= accessoryHeight;

    tableView.contentInset = UIEdgeInsetsMake(0, 0, accessoryHeight, 0);
    tableView.scrollIndicatorInsets = UIEdgeInsetsMake(0, 0, accessoryHeight, 0);
}

if(keyboardOverlap < 0)
    keyboardOverlap = 0;

if(keyboardOverlap != 0)
{
    tableFrame.size.height -= keyboardOverlap;

    NSTimeInterval delay = 0;
    if(keyboardRect.size.height)
    {
        delay = (1 - keyboardOverlap/keyboardRect.size.height)*animationDuration;
        animationDuration = animationDuration * keyboardOverlap/keyboardRect.size.height;
    }

    [UIView animateWithDuration:animationDuration delay:delay 
                        options:UIViewAnimationOptionBeginFromCurrentState 
                     animations:^{ tableView.frame = tableFrame; } 
                     completion:^(BOOL finished){ [self tableAnimationEnded:nil finished:nil contextInfo:nil]; }];
}
}

- (void)keyboardWillHide:(NSNotification *)aNotification
{
if(!keyboardShown)
    return;

keyboardShown = NO;

UIScrollView *tableView;
if([self.tableView.superview isKindOfClass:[UIScrollView class]])
    tableView = (UIScrollView *)self.tableView.superview;
else
    tableView = self.tableView;
if(self.inputAccessoryView)
{
    tableView.contentInset = UIEdgeInsetsZero;
    tableView.scrollIndicatorInsets = UIEdgeInsetsZero;
}

if(keyboardOverlap == 0)
    return;

// Get the size & animation details of the keyboard
NSDictionary *userInfo = [aNotification userInfo];
NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
CGRect keyboardRect = [tableView.superview convertRect:[aValue CGRectValue] fromView:nil];

NSTimeInterval animationDuration;
[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] getValue:&animationDuration];
UIViewAnimationCurve animationCurve;
[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] getValue:&animationCurve];

CGRect tableFrame = tableView.frame; 
tableFrame.size.height += keyboardOverlap;

if(keyboardRect.size.height)
    animationDuration = animationDuration * keyboardOverlap/keyboardRect.size.height;

[UIView animateWithDuration:animationDuration delay:0 
                    options:UIViewAnimationOptionBeginFromCurrentState 
                 animations:^{ tableView.frame = tableFrame; } 
                 completion:nil];
}

- (void) tableAnimationEnded:(NSString*)animationID finished:(NSNumber *)finished contextInfo:(void *)context
{
// Scroll to the active cell
if(self.activeCellIndexPath)
{
    [self.tableView scrollToRowAtIndexPath:self.activeCellIndexPath atScrollPosition:UITableViewScrollPositionNone animated:YES];
    [self.tableView selectRowAtIndexPath:self.activeCellIndexPath animated:NO scrollPosition:UITableViewScrollPositionNone];
}
}

Notes:

A。以上两种方法均已添加到通知中心，代码如下：

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];

b.上面使用的 ivars 声明如下：

BOOL keyboardShown;
CGFloat keyboardOverlap;

C。 'self.activeCellIndexPath' 始终设置为拥有当前活动 UITextField/UITextView 的单元格的索引路径。

享受！ :)