我也有同样的问题。对我来说，误差是0.5像素。

2020-08-06 21:33:20.947369+0530 DemoNestedTableView[4181:384993] [LayoutConstraints] Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want. 
    Try this: 
        (1) look at each constraint and try to figure out which you don't expect; 
        (2) find the code that added the unwanted constraint or constraints and fix it. 
(

        "<NSLayoutConstraint:0x600000a3abc0 UICollectionView:0x7fde0780c200.height == 326   (active)>",
        "<NSLayoutConstraint:0x600000a3ae40 V:|-(0)-[UICollectionView:0x7fde0780c200]   (active, names: '|':UITableViewCellContentView:0x7fde05e0cb10 )>",
        "<NSLayoutConstraint:0x600000a3af30 V:[UICollectionView:0x7fde0780c200]-(0)-|   (active, names: '|':UITableViewCellContentView:0x7fde05e0cb10 )>",
        "<NSLayoutConstraint:0x600000a2a4e0 'UIView-Encapsulated-Layout-Height' UITableViewCellContentView:0x7fde05e0cb10.height == 326.5   (active)>"
    )

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600000a3abc0 UICollectionView:0x7fde0780c200.height == 326   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.

只要加上这个就行了。

self.tableView.separatorStyle = .none

99.9%的情况下，当使用自定义单元格或标头时，UITableViews的所有冲突都发生在表第一次加载时。一旦加载，你通常不会再看到冲突。

This happens because most developers typically use a fixed height or anchor constraint of some sort to layout an element in the cell/header. The conflict occurs because when the UITableView first loads/being laid out, it sets the height of its cells to 0. This obviously conflicts with your own constraints. To solve this, simply set any fixed height constraints to a lower priority (.defaultHigh). Read carefully the console message and see which constraint the layout system decided to break. Usually this is the one that needs its priority changed. You can change the priority like this:

let companyNameTopConstraint = companyNameLabel.topAnchor.constraint(equalTo: companyImageView.bottomAnchor, constant: 15)
    companyNameTopConstraint.priority = .defaultHigh

NSLayoutConstraint.activate([
            companyNameTopConstraint,
           the rest of your constraints here
            ])

设置该视图。translatesAutoresizingMaskIntoConstraints = NO;应该能解决这个问题。

试着降低你的_collapsedtextHeightConstraint的优先级到999。这样，系统提供的uiview - encapsulation - layout - height约束总是优先的。

它基于你在-tableView: highightforrowatindexpath:中返回的内容。确保返回正确的值和你自己的约束，生成的值应该是相同的。您自己的约束的较低优先级只是暂时需要，以防止折叠/展开动画运行时发生冲突。

补充:虽然系统提供的约束是否正确是有争议的，但与框架争论是没有意义的。简单地接受系统约束优先。如果您认为系统约束是错误的，请确保从委托返回正确的rowHeight。

在我的案例中，我通过设置Xcode抱怨的约束的优先级为750来设法摆脱警告，但在删除并重新插入到表后，单元格仍然使用错误的高度。

问题来自于对beginUpdates()和endpdates()的调用(在我做删除和插入的地方之间)方法被封装在UIView.animate(withDuration:)动画块中，我想在更新表时控制动画的持续时间。 删除对动画块的调用为我解决了这个问题。

与其通知表视图更新它的约束，不如尝试重新加载单元格:

[tableView beginUpdates];

[_briefCell collapse:!_showFullBriefText];

[tableView reloadRowsAtIndexPaths:@[[tableView indexPathForCell:_briefCell]] withRowAnimation:UITableViewRowAnimationNone];

[tableView endUpdates];

uiview - encapsulation - layout - height可能是表格视图在初始加载期间为单元格计算的高度，基于单元格当时的约束。