iphone - 通用 UITableView 键盘大小调整算法

Question

我搜索了很多代码来调整 TableView 的大小以适应键盘的显示和隐藏，但几乎我遇到的每一篇文章都假设 TableView 正在使用其 View Controller 的整个 View 。我有一个 iPad 应用程序，其中表格 View 仅占据屏幕的一部分。在这种情况下调整 TableView 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)

Answer 1

以下代码可满足您的需求，适用于任何设备和任何布局。代码由 Sensible TableView framework 提供(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];
}
}

注意事项:

一个。以上两种方法已经使用以下代码添加到通知中心:

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

上面使用的 ivars 声明如下:

BOOL keyboardShown;
CGFloat keyboardOverlap;

“self.activeCellIndexPath”始终设置为拥有当前事件的 UITextField/UITextView 的单元格的索引路径。

尽情享受吧! :)