ios - UITableViewCell 不自动调整大小
问题描述
我在 UITableViewCell 子类中有两个标签。我希望两个标签都是多行标签,所以我将它们的行数设置为零。但问题是我的表格视图单元格没有扩展。事实上,即使我将两个标签的抗压优先级设置为 1000,标签也会被压扁。
我已将 UILabel 属性的背景设置firstLabel
为橙色,并将 UILabel 属性的背景设置secondLabel
为黄色,以便更容易查看标签。每行之间还有一个分隔线,以便更容易看到高度。
这是在设备上运行时视图的外观。标签全部被压缩,无论我在约束中添加多少填充或在标签中放入多少内容,行的大小都不会增加。此外,第一行中的第一个标签有足够的内容,它应该不止一行,但它会被截断...
。
这是我为此使用的代码。第一部分是具有两个标签的表格视图单元子类 - firstLabel(左侧)和 secondLabel(右侧)。接下来,我有包含表格视图的视图的代码,并显示了表格视图的配置方式。最后,还有一个 UITableView 子类,将 table 的 intrinsicContentSize 设置为 table 的内容大小。我添加了这个,因为没有这个表格框架总是保持为零,所以表格视图数据源方法不会被调用。如果有人也知道更好的方法来做到这一点,那将不胜感激。
UITableViewCell 子类
这是我的 UITableViewCell 的实现。它以编程方式使用,所以我是
@interface MyTableViewCell ()
@property (strong, nonatomic) UILabel *firstLabel;
@property (strong, nonatomic) UILabel *secondLabel;
@end
@implementation MyTableViewCell
- (instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier {
if (self = [super initWithStyle:style reuseIdentifier:reuseIdentifier]) {
[self initialize];
}
return self;
}
- (void)initialize {
[self.contentView setBackgroundColor:[UIColor systemTealColor]];
[self.backgroundView setBackgroundColor:[UIColor systemGrayColor]];
[self addSubview:self.firstLabel];
[self addSubview:self.secondLabel];
NSLayoutConstraint *heightConstraint = [self.heightAnchor constraintEqualToConstant:1.0f];
[heightConstraint setPriority:50];
[NSLayoutConstraint activateConstraints:@[
[self.firstLabel.leadingAnchor constraintEqualToAnchor:self.contentView.layoutMarginsGuide.leadingAnchor],
[self.firstLabel.topAnchor constraintEqualToAnchor:self.contentView.layoutMarginsGuide.topAnchor],
[self.firstLabel.trailingAnchor constraintEqualToAnchor:self.centerXAnchor constant:-4.0f],
[self.secondLabel.leadingAnchor constraintEqualToAnchor:self.centerXAnchor constant:4.0f],
[self.secondLabel.topAnchor constraintEqualToAnchor:self.contentView.layoutMarginsGuide.topAnchor],
[self.secondLabel.trailingAnchor constraintEqualToAnchor:self.contentView.layoutMarginsGuide.trailingAnchor],
[self.contentView.layoutMarginsGuide.bottomAnchor constraintGreaterThanOrEqualToAnchor:self.firstLabel.bottomAnchor constant:20.0f],
[self.contentView.layoutMarginsGuide.bottomAnchor constraintGreaterThanOrEqualToAnchor:self.secondLabel.bottomAnchor constant:20.0f],
heightConstraint
]];
}
- (UILabel *)firstLabel {
if (!self->_firstLabel) {
self->_firstLabel = [[UILabel alloc] init];
self->_firstLabel.translatesAutoresizingMaskIntoConstraints = NO;
self->_firstLabel.numberOfLines = 0;
self->_firstLabel.userInteractionEnabled = NO;
self->_firstLabel.contentMode = UIViewContentModeScaleToFill;
[self->_firstLabel setContentHuggingPriority:251 forAxis:UILayoutConstraintAxisHorizontal];
[self->_firstLabel setContentHuggingPriority:251 forAxis:UILayoutConstraintAxisVertical];
[self->_firstLabel setContentCompressionResistancePriority:UILayoutPriorityRequired forAxis:UILayoutConstraintAxisHorizontal];
[self->_firstLabel setContentCompressionResistancePriority:UILayoutPriorityRequired forAxis:UILayoutConstraintAxisVertical];
self->_firstLabel.textAlignment = NSTextAlignmentNatural;
self->_firstLabel.lineBreakMode = NSLineBreakByTruncatingTail;
self->_firstLabel.baselineAdjustment = UIBaselineAdjustmentAlignBaselines;
self->_firstLabel.adjustsFontSizeToFitWidth = NO;
self->_firstLabel.backgroundColor = [UIColor orangeColor];
}
return self->_firstLabel;
}
- (UILabel *)secondLabel {
if (!self->_secondLabel) {
self->_secondLabel = [[UILabel alloc] init];
self->_secondLabel.translatesAutoresizingMaskIntoConstraints = NO;
self->_secondLabel.numberOfLines = 0;
self->_secondLabel.userInteractionEnabled = NO;
self->_secondLabel.contentMode = UIViewContentModeScaleToFill;
[self->_secondLabel setContentHuggingPriority:251 forAxis:UILayoutConstraintAxisHorizontal];
[self->_secondLabel setContentHuggingPriority:251 forAxis:UILayoutConstraintAxisVertical];
[self->_secondLabel setContentCompressionResistancePriority:UILayoutPriorityRequired forAxis:UILayoutConstraintAxisHorizontal];
[self->_secondLabel setContentCompressionResistancePriority:UILayoutPriorityRequired forAxis:UILayoutConstraintAxisVertical];
self->_secondLabel.textAlignment = NSTextAlignmentNatural;
self->_secondLabel.lineBreakMode = NSLineBreakByTruncatingTail;
self->_secondLabel.baselineAdjustment = UIBaselineAdjustmentAlignBaselines;
self->_secondLabel.adjustsFontSizeToFitWidth = NO;
self->_secondLabel.backgroundColor = [UIColor yellowColor];
}
return self->_secondLabel;
}
- (void)setData:(MyModel *)data {
self.firstLabel.text = data.first;
self.secondLabel.text = data.second;
[self invalidateIntrinsicContentSize];
}
@end
Primary View - 有一个表视图作为子视图
这是显示的实际视图。作为较大应用程序的一部分,此视图随后显示在垂直 UIStackView 中。
此视图有一个表视图作为唯一的子视图,并且表视图使用 AutoLayout 固定到此视图的边缘。UITableView 实际上是另一个名为“AutosizingTableView”的类的实例,用于使表格视图自动调整大小(没有这个,表格的框架保持为零,并且表格视图数据源方法,tableView:cellForRowAtIndexPath:
因为表格高度为零。此表视图的代码包含在本节之后。
@interface MyView ()
@property (strong, nonatomic) AutosizingTableView *tableView;
@end
@implementation MyView
- (instancetype)init {
return [self initWithFrame:CGRectZero];
}
- (instancetype)initWithCoder:(NSCoder *)coder {
if (self = [super initWithCoder:coder]) {
[self initialize];
}
return self;
}
- (instancetype)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
[self initialize];
}
return self;
}
- (void)initialize {
[self addSubview:self.tableView];
[NSLayoutConstraint activateConstraints:@[
[self.tableView.leadingAnchor constraintEqualToAnchor:self.leadingAnchor],
[self.tableView.topAnchor constraintEqualToAnchor:self.topAnchor],
[self.tableView.trailingAnchor constraintEqualToAnchor:self.trailingAnchor],
[self.tableView.bottomAnchor constraintEqualToAnchor:self.bottomAnchor],
[self.tableView.widthAnchor constraintEqualToAnchor:self.widthAnchor]
]];
}
- (UITableView *)tableView {
if (!self->_tableView) {
self->_tableView = [[AutosizingTableView alloc] initWithFrame:CGRectZero style:UITableViewStylePlain];
self->_tableView.translatesAutoresizingMaskIntoConstraints = NO;
self->_tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
self->_tableView.rowHeight = UITableViewAutomaticDimension;
self->_tableView.estimatedRowHeight = UITableViewAutomaticDimension;
self->_tableView.allowsSelection = NO;
self->_tableView.scrollEnabled = NO;
self->_tableView.delegate = self;
self->_tableView.dataSource = self;
[self->_tableView registerClass:[MyTableViewCell class] forCellReuseIdentifier:@"myTableViewCell"];
}
return self->_tableView;
}
- (void)setdata:(NSArray<MyData *> *)data {
self->_data = data;
[self.tableView reloadData];
}
#pragma mark - UITableViewDataSource
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return self.data.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
MyTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"myTableViewCell" forIndexPath:indexPath];
MyData *data = self.data[indexPath.row];
cell.detail = detail;
return cell;
}
@end
自动调整表格视图
正如上一节中提到的,这只是为了让表格视图自动调整大小。没有这个,表格视图高度为零并保持为零,因为由于tableView:cellForRowAtIndexPath:
表格视图高度,该方法从未被调用。
@implementation AutosizingTableView
- (CGSize)intrinsicContentSize {
return self.contentSize;
}
- (void)setContentSize:(CGSize)contentSize {
[super setContentSize:contentSize];
[self invalidateIntrinsicContentSize];
}
@end
解决方案
尝试这个:
- (void)initialize {
[self.contentView setBackgroundColor:[UIColor systemTealColor]];
[self.backgroundView setBackgroundColor:[UIColor systemGrayColor]];
[self.contentView addSubview:self.firstLabel];
[self.contentView addSubview:self.secondLabel];
NSLayoutConstraint *heightConstraint = [self.heightAnchor constraintEqualToConstant:1.0f];
[heightConstraint setPriority:50];
[NSLayoutConstraint activateConstraints:@[
[self.firstLabel.leadingAnchor constraintEqualToAnchor:self.contentView.layoutMarginsGuide.leadingAnchor],
[self.firstLabel.topAnchor constraintEqualToAnchor:self.contentView.layoutMarginsGuide.topAnchor],
[self.firstLabel.trailingAnchor constraintEqualToAnchor:self.centerXAnchor constant:-4.0f],
[self.secondLabel.leadingAnchor constraintEqualToAnchor:self.centerXAnchor constant:4.0f],
[self.secondLabel.topAnchor constraintEqualToAnchor:self.contentView.layoutMarginsGuide.topAnchor],
[self.secondLabel.trailingAnchor constraintEqualToAnchor:self.contentView.layoutMarginsGuide.trailingAnchor],
[self.contentView.layoutMarginsGuide.bottomAnchor constraintGreaterThanOrEqualToAnchor:self.firstLabel.bottomAnchor constant:20.0f],
[self.contentView.layoutMarginsGuide.bottomAnchor constraintGreaterThanOrEqualToAnchor:self.secondLabel.bottomAnchor constant:20.0f],
heightConstraint
]];
}
您应该将标签添加到 contentView 而不是直接添加单元格。
推荐阅读
- c# - Newtonsoft json 将缺少的 int 值反序列化为空值而不是零
- python - How to properly configure a Service Account in Google AppEngine Flex w/ Python?
- javascript - Div 切换它的显示开/关,但能够单击输入
- visual-studio-code - How setup VSCode + Chrome Debugger + Docker in MacOS (Docker for Mac)
- html - 更改 submit_tag 上的文本
- mysql-error-1064 - #1045 - Access denied
- javascript - Will servlet filter for cache control can create out of memory issue?
- node.js - when unit testing shelljs doesn't use my mocked filesystem but the real one
- python - 如果没有返回异常,则传递异常并引发错误的方法
- java - Spring JPA - 具有相同ID的不同实体