显示键盘时，iOS UITableView contentOffset [英] iOS UITableView contentOffset when keyboard is shown

问题描述

我正在尝试在显示keyboard时设置tableView的contentOffset.实际代码位于CustomTableView : UITableView <UIScrollViewDelegate>内部，因为该代码在整个应用程序中得到了广泛使用，因此将self用作tableView. 我的代码如下:

I am trying to set the contentOffset of a tableView when the keyboard is presented. The actual code is inside a CustomTableView : UITableView <UIScrollViewDelegate>, as it is used widely throughout the app, hence the use of self as the tableView. My code looks like this:

- (void)keyboadDidAppear:(NSNotification *)notification {
    NSTimeInterval animationDuration = [[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    CGRect keyboardBeginFrame = [[[notification userInfo] objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue];
    CGFloat keyboardHeight = CGRectGetHeight(keyboardBeginFrame);
    CGPoint contentOffset = self.contentOffset;
    originalContentOffset = self.contentOffset;//hold reference to reset it when keyboard is hidden
    contentOffset.y += keyboardHeight;
    [UIView animateWithDuration:animationDuration animations:^{
        [self layoutIfNeeded];
    } completion:^(BOOL finished) {
        if (finished) {
            [self setContentOffset:contentOffset animated:YES];
        }
    }];
}

问题在于，它总是使内容偏移键盘的高度，这是错误的，当用户点击靠近tableView顶部的tableCell时. 理想情况下，我想偏移内容，以便点击的tableCell恰好在键盘上方. 问题是我不知道该怎么做.我有一个大概的想法，我需要这样的东西:

The problem is that, it always offsets the content by the keyboard's height, which is wrong, when the user taps a tableCell that is near the top of the tableView. Ideally, I would want to offset the content so the tapped tableCell is just above the keyboard. The problem is that I don't know how to do it. I have a rough idea that I would need something like:

distanceBetweenTappedCellAndTableBottom > keyboardHeight ? do nothing : offsetContentBy keyboardHeight + tappedCellHeight.

关于如何得出这些数字的任何建议?还是有更好的解决方案?

Any suggestions on how could I come up with the numbers? or is there a better solution?

以后

我不能使用contentInset，因为tableView具有sectionHeaders，并且设置contentInset会导致sectionHeaders保持固定，而rows向上移动.

I can't use the contentInset as the tableView has sectionHeaders, and setting the contentInset causes the sectionHeaders to stay fixes, while the rows move up.

解决方案，基于以下建议:

CGSize kbSize = [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
    NSTimeInterval duration = [[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];

    CGFloat height = UIDeviceOrientationIsPortrait([[UIDevice currentDevice] orientation]) ? kbSize.width : kbSize.height;

    height += 10.0;//it needs to be slightly higher so the textField is clearly visible.
    originalEdgeInset = self.contentInset;
    __weak typeof (self) block = self;
    [UIView animateWithDuration:duration animations:^{
        UIEdgeInsets edgeInsets = block.contentInset;
        edgeInsets.bottom += height;
        block.contentInset = edgeInsets;
        edgeInsets = block.scrollIndicatorInsets;
        edgeInsets.bottom += height;
        block.scrollIndicatorInsets = edgeInsets;
    }];

推荐答案

当您将键盘高度也添加到edgeInset中时，我认为键盘不会移动

I think keyboard will not move when you add keyboard height into edgeInset as well

  CGSize kbSize = [[[sender userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
NSTimeInterval duration = [[[sender userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];

CGFloat height = UIDeviceOrientationIsPortrait([[UIDevice currentDevice] orientation]) ? kbSize.width : kbSize.height;

[UIView animateWithDuration:duration animations:^{
    UIEdgeInsets edgeInsets = _generalTableView.contentInset;
    edgeInsets.bottom += height;
    _generalTableView.contentInset = edgeInsets;
    edgeInsets = _generalTableView.scrollIndicatorInsets;
    edgeInsets.bottom += height;
    _generalTableView.scrollIndicatorInsets = edgeInsets;
}];

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