相关疑难解决方法(0)

如何UITableViewCell在表格视图中使用s 内的自动布局,让每个单元格的内容和子视图确定行高(本身/自动),同时保持平滑的滚动性能？

我正在使用Xcode 6 Beta 3,iOS 8 SDK.使用Swift构建目标iOS 7.0.请通过以下屏幕截图逐步查看我的问题.

我在Storyboard中有一个UICollectionView.1原型UICollectionViewCell,中心包含1个标签(无自动调整规则).紫色背景是标记我在运行时由Cell生成的contentView.该视图最终将基于我的UICollectionViewLayoutDelegate正确调整大小,但不会在iOS 7上调整大小.请注意,我使用的是Xcode 6,问题只发生在iOS 7上.

当我在iOS 8上构建应用程序时.一切都很好.

注意:紫色是contentView,蓝色是我的带有圆角的UIButton.

但是,在iOS 7上,Cell中的所有子视图突然缩小到(0,0,50,50)的帧,并且永远不再符合我的自动调整规则.

我认为这是iOS 8 SDK或Swift或Xcode中的错误？

更新1:官方Xcode 6.0.1中仍存在此问题!最好的解决方法就像KoCMoHaBTa在下面通过设置单元格的cellForItem中的框架所建议的那样(你必须为你的单元子类化).事实证明,这是iOS 8 SDK和iOS 7之间的不兼容性(请查看Apple引用的ecotax的答案).

更新2: 将此代码粘贴到cellForItem的开头,事情应该没问题:

/** Xcode 6 on iOS 7 hot fix **/
cell.contentView.frame = cell.bounds;
cell.contentView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
/** End of Xcode 6 on iOS 7 hot fix **/

我在UITableView上遇到了一个非常奇怪的问题.我有一些不同的单元格,我想在类似新闻源的表视图上显示.

我重用后我的细胞有问题.单元格包含两个图像,两个标签和一个带共享/喜欢/注释按钮的视图.我会尝试绘制它,但我不确定它会漂亮:

-------------------------------------------------
|       |   __    ____________________________  |
|       |  |_2|  |                            | |
|       |        |              3             | |
|       |        |                            | |
|   1   |        |____________________________| |
|       |                                       |
|       |_______________________________________|
|       |                                       |
|       |                  4                    |
|_______|_______________________________________|
|                                               |
|                       5                       |
|_______________________________________________|

1 : objectImage
2 : subjectImage
3 : titleLabel
4 : commentLabel
5 : actionsView

我的约束是:

"H:|-0-[objectImage(60)]-7-[subjectImage(30)]-7-[titleLabel]-7-|"
"H:|-0-[objectImage(60)]-0-[commentLabel]-0-|"
"H:|-0-[actionsView]-0-|"
"V:|-0-[objectImage(>=35)]-0-[actionsView(44)]-0-|"
"V:|-7-[subjectImage(30)]"
"V:|-7-[titleLabel(>=46)]-7-[commentLabel(>=35)]-0-[actionsView(44)]-0-|"

每次绘制单元格时,我都会更改此约束:

"V:[commentLabel(%0.2f)]"

细胞第一次完美展示.

但是,我遇到的问题是,在某些时候,经过一些重用(我不能每次都重现它),应用程序因为一个约束问题而崩溃.这是一个例外:

"<NSLayoutConstraint:0x205a75b0 V:[UILabel:0x1ef31430(105)]>",
"<NSLayoutConstraint:0x1ef34440 V:[UILabel:0x1ef31430]-(0)-[UIView:0x1ef2fe50]>",
"<NSLayoutConstraint:0x1ef34380 …

我正在尝试将自动布局合并到我的UITableViewHeaderFooterView子类中.这个课程非常基础,只有两个标签.这是完整的子类:

@implementation MBTableDetailStyleFooterView

static void MBTableDetailStyleFooterViewCommonSetup(MBTableDetailStyleFooterView *_self) {
    UILabel *rightLabel = [[UILabel alloc] init];
    _self.rightLabel = rightLabel;
    rightLabel.translatesAutoresizingMaskIntoConstraints = NO;
    [_self.contentView addSubview:rightLabel];

    UILabel *leftLabel = [[UILabel alloc] init];
    _self.leftLabel = leftLabel;
    leftLabel.translatesAutoresizingMaskIntoConstraints = NO;
    [_self.contentView addSubview:leftLabel];

    NSDictionary *views = NSDictionaryOfVariableBindings(rightLabel, leftLabel);

    NSArray *horizontalConstraints = [NSLayoutConstraint constraintsWithVisualFormat:@"|-10-[leftLabel]-(>=10)-[rightLabel]-10-|" options:0 metrics:nil views:views];
    [_self.contentView addConstraints:horizontalConstraints];

    // center views vertically in super view
    NSLayoutConstraint *leftCenterYConstraint = [NSLayoutConstraint constraintWithItem:leftLabel attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:_self.contentView attribute:NSLayoutAttributeCenterY multiplier:1 constant:0];
    [_self.contentView addConstraint:leftCenterYConstraint];
    NSLayoutConstraint *rightCenterYConstraint = [NSLayoutConstraint constraintWithItem:rightLabel attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:_self.contentView attribute:NSLayoutAttributeCenterY …

我正在以编程方式使用自动布局约束,并且我经常在我的应用程序中看到同样的错误,通常与看起来像这样的约束相关:

"<NSAutoresizingMaskLayoutConstraint:0x82da910 h=--& v=--& V:[UITableViewCellContentView:0x82d9fb0(99)]>"

我在https://github.com/nicolasccit/AutoLayoutCellWarning上放了一些示例代码来重现

在这个例子中,我创建了一个包含2个UI元素的非常简单的视图:一个名为imageThumbnail的图像视图和一个名为labelName的标签,带有一些约束:

"H:|-padding-[_imageThumbnail(==imageWidth)]-[_labelName]";
"V:|-padding-[_imageThumbnail(==imageHeight)]-padding-|";
"V:|-padding-[_labelName]";

在这两个元素上,我将AutoresizingMaskIntoConstraints设置为NO.

我得到以下例外:

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:0xa6e4f90 …

当我在iPhone上运行我的应用程序时,我收到以下错误.当我在模拟器中运行它时,我没有.如果我把它-12-|带走,那么单元格的高度就会崩溃到30像素.用户界面打破了.有人能帮帮我,告诉我为什么吗？

谢谢

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:0x170285ff0 V:|-(12)-[UIImageView:0x1741ec200]   (Names: '|':UITableViewCellContentView:0x17419c7d0 )>",
"<NSLayoutConstraint:0x170286040 …