在编辑时防止缩进UITableViewCell（contentView） [英] Prevent indentation of UITableViewCell (contentView) while editing

问题描述

是否可以保持 contentView.frame 始终相同，而不管 tableView.editing ？我已经尝试重写 layoutSubviews 和 willTransitionToState 但这些选项也失败了。我似乎不能够改变contentView的宽度。或者也许我的方法根本不可能...
也许还有另一种方法来解决这个问题。

Is it possible to keep the contentView.frame always the same, regardless of tableView.editing? I already tried to override layoutSubviews and willTransitionToState but those options fizzled out too. I can't seem to be able to change the width of the contentView. Or maybe my approach ist just plain impossible ... Maybe there is another way to solve this.

我想实现的行为如下：希望始终缩进的 UITableViewCell 的标准 textLabel tableView进入编辑模式。我可能会面临的问题是 detailTextLabel 的行为将必须更正（例如截断文本，如果 textLabel 内容太长）。我不想实现我自己的 UILabel 的原因是因为自定义子视图会大幅降低滚动性能。

The behaviour I want to achieve is the following: I want the standard textLabel of a UITableViewCell to be always indented and not change position when the tableView enters editing mode. The problem I will probably face is that the behaviour of the detailTextLabel will have to be corrected (e.g. truncation of text if textLabelcontent is too long). The reason why I don't want to implement my own UILabelis because a custom subviews will decrease the scrolling performance by a significant amount.

我希望任何人已经在他们的 UITableView 中实现了这样的东西，并可以给我一个解决这个冗长的问题的解决方案。提前感谢！

I hope that anyone already implemented something like this in their UITableViewand could show me a solution to this tedious problem. Thanks in advance!

编辑：我处理的是一个 UITableView p>

I'm dealing with a UITableView in plain and not grouped style.

推荐答案

幸运的是，iOS完全可以保持任何值不变。

Luckily, iOS is perfectly equipped to keep whatever value constant.

这个（丑陋的）代码段将框架固定为 origin.x == 0 的任何值。

This (ugly) piece of code will keep the frame fixed to whatever value has origin.x==0. This is easily adapted to your particular needs.

// put this in your UITableViewCell subclass
-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
    NSLog(@"observed value for kp %@ changed: %@",keyPath,change);
    if ( [keyPath isEqual:@"frame"] && object == self.contentView )
    {
        CGRect newFrame = self.contentView.frame;
        CGRect oldFrame = [[change objectForKey:NSKeyValueChangeOldKey] CGRectValue];
        NSLog(@"frame old: %@  new: %@",NSStringFromCGRect(oldFrame),NSStringFromCGRect(newFrame));

        if ( newFrame.origin.x != 0 ) self.contentView.frame = oldFrame;
    }
}

// add the cell as an observer for frame changes, somewhere in initialization:
[self.contentView addObserver:self forKeyPath:@"frame" options:NSKeyValueObservingOptionOld context:nil];

// IMPORTANT: remove the cell as an observer in -dealloc:
[self.contentView removeObserver:self forKeyPath:@"frame"];

这将只允许框架更改为 origin.x == 0 。删除发布版本的 NSLog（）行。

This will only allow the frame to change to values with an origin.x==0. Remove the NSLog() lines for Release builds.

我已经测试了几分钟，见到任何副作用。

I have tested this for a few minutes and haven't seen any side effect.

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