I'm working on making a custom list cell (collection view list cell), based on

So, to clarify where the LiveChannelContentView is, I just add the yellow background to the view. There are two things I don't get. First, even Xcode tells me that

    Will attempt to recover by breaking constraint 

    <NSLayoutConstraint:0x2812371b0 UIView:0x128c136b0.height == 60   (active)>

when I take a screenshot of the app and measure the yellow background UIView's height, it is still 60. I thought breaking constraint means that using other height constraints instead of 60, but is that wrong?

Another thing is I was curious where the

"<NSAutoresizingMaskLayoutConstraint:0x281209220 h=--& v=--& liveTest.LiveChannelContentView:0x128c13430.height == 44 (active)>" is used in my code. I searched the file contains 44 in my workspace but I got nothing.

Not really sure, but I thought the height of 44 and 60 is applied to the same UIView and Xcode got rid of the 60's height anchor or something. However, when I delete the height anchor for the contentsView, contentsView.heightAnchor.constraint(equalToConstant: 60), the app crashed like below.

I also tried deleting the top or the bottom anchor of the contentsView, but it also crushed the app.

contentsView.topAnchor.constraint(equalTo: layoutMarginsGuide.topAnchor),

or

contentsView.bottomAnchor.constraint(equalTo: layoutMarginsGuide.bottomAnchor),

So can anyone tell me which constraint should I fix to get rid of the waring please?

CodePudding user response：

Change this part

    contentsView.translatesAutoresizingMaskIntoConstraints = false
    NSLayoutConstraint.activate([
        contentsView.leadingAnchor.constraint(equalTo: layoutMarginsGuide.leadingAnchor),
        contentsView.trailingAnchor.constraint(equalTo: layoutMarginsGuide.trailingAnchor),
        contentsView.topAnchor.constraint(equalTo: layoutMarginsGuide.topAnchor),
        contentsView.bottomAnchor.constraint(equalTo: layoutMarginsGuide.bottomAnchor),
        contentsView.heightAnchor.constraint(equalToConstant: 60)
    ])

to

contentsView.translatesAutoresizingMaskIntoConstraints = false

let con = contentsView.bottomAnchor.constraint(equalTo: layoutMarginsGuide.bottomAnchor)
con.priority = UILayoutPriority(rawValue: 999)  
    NSLayoutConstraint.activate([
        contentsView.leadingAnchor.constraint(equalTo: layoutMarginsGuide.leadingAnchor),
        contentsView.trailingAnchor.constraint(equalTo: layoutMarginsGuide.trailingAnchor),
        contentsView.topAnchor.constraint(equalTo: layoutMarginsGuide.topAnchor),
        con,
        contentsView.heightAnchor.constraint(equalToConstant: 60)
    ])