UICollectionViewCell自动布局

Question

我在我的故事板中创建了一个简单的自定义UICollectionViewCell，我也通过编程实现了这一点，得到了相同的结果。

它有一个单独的UIImageView和两个UILabels，如下所示：

          <--UIIMAGEVIEW-->          <--UILABEL-------->
|-(10px)- |               | -(10px)-                     -(10px)-|
          <--------------->          <--UILABEL-------->

图像位于左侧，然后在其右侧是彼此上下的两个标签。

每一个都有10个像素的间隔，并且都以单元格Y轴为中心。然后，标签有一个常数来从中心(向上和向下)偏移它们。

图像的高度和宽度固定为44px，标签的高度固定为20px (宽度灵活)。

约束按照预期工作，并且不会破坏应用程序，但它们总是在下面吐出恼人的控制台日志信息，因为它们显然正在破坏。

如果我将这一行添加到我的UICollectionViewCell子类中，约束将不再破坏并发出控制台错误，但它们在屏幕上完全被破坏。

[self.contentView setTranslatesAutoresizingMaskIntoConstraints:NO];

有什么线索吗？这看起来太不合逻辑了！

以下是控制台错误代码：

2014-10-25 18:28:14.273 Air Plan[1579:580797] 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. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x17009edc0 H:[UIImageView:0x1701f7d00(44)]>",
    "<NSLayoutConstraint:0x17009f130 H:|-(10)-[UIImageView:0x1701f7d00]   (Names: '|':UIView:0x170183810 )>",
    "<NSLayoutConstraint:0x17009f270 H:[UIImageView:0x1701f7d00]-(10)-[UILabel:0x155e59970'detailLbl']>",
    "<NSLayoutConstraint:0x17009f310 H:[UILabel:0x155e59970'detailLbl']-(10)-|   (Names: '|':UIView:0x170183810 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x17409eff0 h=--& v=--& H:[UIView:0x170183810(50)]>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x17009edc0 H:[UIImageView:0x1701f7d00(44)]>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
2014-10-25 18:28:14.276 Air Plan[1579:580797] 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. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x17009fcc0 H:[UIImageView:0x1701fa800(44)]>",
    "<NSLayoutConstraint:0x17009ff40 H:|-(10)-[UIImageView:0x1701fa800]   (Names: '|':UIView:0x170180a90 )>",
    "<NSLayoutConstraint:0x1702800a0 H:[UIImageView:0x1701fa800]-(10)-[UILabel:0x155e5b440'detailLbl']>",
    "<NSLayoutConstraint:0x170280140 H:[UILabel:0x155e5b440'detailLbl']-(10)-|   (Names: '|':UIView:0x170180a90 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x17409ea00 h=--& v=--& H:[UIView:0x170180a90(50)]>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x17009fcc0 H:[UIImageView:0x1701fa800(44)]>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
2014-10-25 18:28:14.278 Air Plan[1579:580797] 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. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x170280a00 H:[UIImageView:0x1701fab00(44)]>",
    "<NSLayoutConstraint:0x170280c80 H:|-(10)-[UIImageView:0x1701fab00]   (Names: '|':UIView:0x1701822f0 )>",
    "<NSLayoutConstraint:0x170280dc0 H:[UIImageView:0x1701fab00]-(10)-[UILabel:0x155e5cd10'detailLbl']>",
    "<NSLayoutConstraint:0x170280e60 H:[UILabel:0x155e5cd10'detailLbl']-(10)-|   (Names: '|':UIView:0x1701822f0 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x17409f180 h=--& v=--& H:[UIView:0x1701822f0(50)]>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x170280a00 H:[UIImageView:0x1701fab00(44)]>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
2014-10-25 18:28:14.280 Air Plan[1579:580797] 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. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x170281090 H:[UIImageView:0x1701fae00(44)]>",
    "<NSLayoutConstraint:0x170281310 H:|-(10)-[UIImageView:0x1701fae00]   (Names: '|':UIView:0x170182220 )>",
    "<NSLayoutConstraint:0x1702813b0 H:[UIImageView:0x1701fae00]-(10)-[UILabel:0x155e5d620'titleLbl']>",
    "<NSLayoutConstraint:0x170281400 H:[UILabel:0x155e5d620'titleLbl']-(10)-|   (Names: '|':UIView:0x170182220 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x17409fd60 h=--& v=--& H:[UIView:0x170182220(50)]>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x170281090 H:[UIImageView:0x1701fae00(44)]>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
2014-10-25 18:28:14.282 Air Plan[1579:580797] 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. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x170281b80 H:[UIImageView:0x1701fb100(44)]>",
    "<NSLayoutConstraint:0x17409f4a0 H:|-(10)-[UIImageView:0x1701fb100]   (Names: '|':UIView:0x170182150 )>",
    "<NSLayoutConstraint:0x17409f5e0 H:[UIImageView:0x1701fb100]-(10)-[UILabel:0x155d64210'detailLbl']>",
    "<NSLayoutConstraint:0x17409f680 H:[UILabel:0x155d64210'detailLbl']-(10)-|   (Names: '|':UIView:0x170182150 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x1742800f0 h=--& v=--& H:[UIView:0x170182150(50)]>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x170281b80 H:[UIImageView:0x1701fb100(44)]>

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

Answer 1

我也遇到了这个问题，并通过在UICollectionViewCell子类中添加以下代码来修复它：

SWIFT >= 4.2

override func awakeFromNib() {
    contentView.autoresizingMask = [UIView.AutoresizingMask.flexibleWidth, UIView.AutoresizingMask.flexibleHeight]
}

SWIFT 3

override func awakeFromNib() {
    contentView.autoresizingMask = [UIViewAutoresizing.flexibleWidth, UIViewAutoresizing.flexibleHeight]
}

对象

- (void)awakeFromNib{
    self.contentView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
}

Xcode 6.1 iOS 8.0.2，8.1

你也可以检查这个答案：UICollectionView Cell + UiLabel with AutoLayout

Answer 2

在创建之后，单元格和单元格的内容视图是50x50 (与集合布局设置的大小无关)。

自动布局在单元格大小正确但内容视图仍为50x50后首次生效。可能是iOS 8的问题。其他布局使用正确的内容视图大小。所以你可以看到一个正确的布局，但是日志输出是杂乱的。

只需在iOS 8的内容视图中设置任何大于最小单元格大小的框架即可。

在你的情况下

|-(10px)-UIImageView(44px)-(10px)-UILabel-(10px)-|

最小单元格宽度为74 -所有显式常量之和。

- (void)awakeFromNib {
    [super awakeFromNib];
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.) {
        self.contentView.frame = CGRectMake(0, 0, 200, 100);
    }
}

有相同的问题，但设置auoresizingMask不起作用。而设置框架解决了这个问题。

Answer 3

我也有这个问题。添加：

[self.contentView setTranslatesAutoresizingMaskIntoConstraints:NO];

破坏了我的视图布局。在我的例子中，我必须调整几个布局约束才能使视图返回到我想要的方式。在一种情况下，图像不是垂直居中的，因为单元的高度没有受到足够的约束。(在这里，我向单元格中最低的元素添加了一个底部约束)。在另一种情况下，另一个图像(在不同的单元格中)没有居中，我必须进行不同的约束更改。我在该图像上添加了高度约束，并删除了顶部约束，从而解决了问题。

在这两个单元格中，我也遇到了UILabel的问题，它们不再受集合视图单元格的宽度限制。也就是说，当文本太长时，文本不会很好地以"...“结尾在单元格中，它只会超过单元格的末尾。在这两种情况下，我能想到的唯一解决办法是向标签添加固定宽度约束，从而使标签的宽度不自适应。在将translatesAutoresizingMaskIntoConstraints设置为NO之前，有一些以前有效的尾随约束。