Question

示例：

textLabel和descriptionLabel中的文本不为空

文字说明标签为空

可能会出现Autolayout，或者有必要覆盖某些方法。

Answer 1

如果是自定义标签，这里的简单修复就是只使用一个标签并添加1或2行属性文本。我只是把一个项目放在一起，它运作正常。我已经提供了比您需要更多的解释（您已经知道如何子类化表视图单元格，但对于可能需要它的人，我添加了很多细节）。基本上是：

子类UITableViewCell并添加单个标签。设置自动布局，使标签在单元格中垂直对齐，并设置左右边距。你可能不得不搞乱自动布局来添加填充到顶部或底部，但我会将摔跤与自动布局留给你lol
创建1或2个NSMutableAttributedStrings。如果您只有一个字符串，它将在一行的标签中居中，并在文本周围自动布局。如果您有两行，只需添加一个返回字符。

注意：此代码假定您始终至少拥有标题，副标题是可选的。

这是我使用的tableViewController.m代码

#import "MyTableViewController.h"
#import "CustomCell.h"

@implementation MyTableViewController

- (void)viewDidLoad 
{
    [super viewDidLoad];

    //1. Register custom nib
    [self.tableView registerNib:[UINib nibWithNibName:[CustomCell nibName] bundle:nil] forCellReuseIdentifier:[CustomCell resuseIdentifier]];

    //2. Set a suggested height for auto-layout
    self.tableView.estimatedRowHeight = 45;
}

#pragma mark - UITableView datasource
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView 
{ 
    return 1; 
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section 
{ 
    return 2; 
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    //1. Create an instance of the custom cell
    CustomCell *cell = (CustomCell*)[self.tableView dequeueReusableCellWithIdentifier:[CustomCell resuseIdentifier] forIndexPath:indexPath];

    //2. Setting some filler text (this would come from your data object)
    if (indexPath.row == 0) {
    cell.title = @"A cell with only title text";
    } else {
    cell.title = @"First we have the title";
    cell.subTitle = @"And here is the subtitle";
    }

    return cell;
}

这是自定义UITableViewCell的.h和.m。请记住将故事板中的原型单元子类化为此类。

//  CustomCell.h

#import <UIKit/UIKit.h>

@interface CustomCell : UITableViewCell

+ (NSString *)nibName;
+ (NSString *)resuseIdentifier;

@property (strong, nonatomic) NSString *title;
@property (strong, nonatomic) NSString *subTitle;

@end

最后是CustomCell.m。这很长，所以你必须滚动浏览。对于那个很抱歉。

//  CustomCell.m
#import "CustomCell.h"

//1. Created a typeDef to identify which label we are dealing with
typedef NS_ENUM(NSInteger, CustomLabelType) {
    CustomLabelTypeTitle = 0,
    CustomLabelTypeSubtitle,
};


@interface CustomCell()

//IBOutlet to custom .xib file of UITableViewCell file
@property (weak, nonatomic) IBOutlet UILabel *customLabel;

@end

@implementation CustomCell

+ (NSString *)nibName
{
    return @"CustomCell";
}

+ (NSString *)resuseIdentifier
{
    return @"CustomCellReuseIdentifier";
}

- (void)setTitle:(NSString *)title
{
    _title = title;
}

- (void)setSubTitle:(NSString *)subTitle
{
    _subTitle = subTitle;
}

- (void)setSelected:(BOOL)selected animated:(BOOL)animated 
{
    [super setSelected:selected animated:animated];

    //1. Add a line return after the title if we have a subtitle
    if (self.subTitle) {
    self.title = [NSString stringWithFormat:@"%@%@",self.title, @"\n"];

    //2. Set the title to allow for 2 lines of text
    self.customLabel.numberOfLines = 2;
    }


    NSMutableAttributedString *attTitle;
    NSMutableAttributedString *attSubTitle;

    //3. Set the title
    if (self.title)
    attTitle = [self _mutableStringWithText:self.title type:CustomLabelTypeTitle];

    //4. If we have a subtitle, append it to the title attributed string
    if (self.title && self.subTitle) {
    attSubTitle = [self _mutableStringWithText:self.subTitle type:CustomLabelTypeSubtitle];
    [attTitle appendAttributedString:attSubTitle];
    }

    //5. Set your label
    [self.customLabel setAttributedText:attTitle];

}

- (NSMutableAttributedString *)_mutableStringWithText:(NSString *)labelText type:(CustomLabelType)labelType
{
    //1. Create attributes for title vs subtitle
    UIFont *labelFont = [UIFont systemFontOfSize: (labelType == CustomLabelTypeTitle) ? 16 : 12];
    UIColor *textColor = (labelType == CustomLabelTypeTitle) ? [UIColor blackColor] : [UIColor grayColor];

    //2. Create the paragraph style you want, including line spacing
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    [paragraphStyle setLineSpacing:6.5];
    paragraphStyle.alignment = NSTextAlignmentLeft;

    //3. Create your attributes dictionary
    NSDictionary *paragraphAttributes = @{NSParagraphStyleAttributeName: paragraphStyle, NSFontAttributeName: labelFont, NSForegroundColorAttributeName:textColor};

    //4. Create and return your string
    NSMutableAttributedString *mutableString = [[NSMutableAttributedString alloc] initWithString:labelText attributes:paragraphAttributes];

    return mutableString;   
}


@end

Answer 2

好的，回答1.1版。这次我们这样做：

添加你的top titleLabel：在自动布局中为superview设置一个垂直约束。转到尺寸检查器并将常量更改为-15（将其向上滑动）。将另一个约束设置为视图顶部，以便填充任何内容。将该约束的优先级设置为900.
现在控制从tltleLabel的垂直约束拖动到.m文件的界面，以创建约束的出口。

添加您的底部副标题标签：使用乘数1.5（或任何您需要使其看起来正常）的超级视图设置垂直约束。不要添加任何与顶部标签显示关系的约束。
在您的代码中，如果您有副标题，那么只需填写标签就可以了。如果您没有副标题，则将副标题设置为隐藏，并将titleLabel垂直约束的常量值更改为0，使其居中。证明完毕

这里是CustomCell类的新代码。应该是第一次这样做。比我做的第一个解决方案容易100％（我在咖啡上跳了起来）。希望这对你有用。

//  CustomCell.m

#import "CustomCell.h"

@interface CustomCell()

//IBOutlet to custom .xib file of UITableViewCell file
@property (weak, nonatomic) IBOutlet UILabel *titleLabel;
@property (weak, nonatomic) IBOutlet UILabel *subtitleLabel;

//This is the new outlet to the contraint.
@property (weak, nonatomic) IBOutlet NSLayoutConstraint *titleLabelVerticalConstraint;

@end

@implementation CustomCell

+ (NSString *)nibName
{
    return @"CustomCell";
}

+ (NSString *)resuseIdentifier
{
    return @"CustomCellReuseIdentifier";
}

- (void)setTitle:(NSString *)title
{
    _title = title;
    self.titleLabel.text = self.title;
}

- (void)setSubTitle:(NSString *)subTitle
{
    _subTitle = subTitle;
    self.subtitleLabel.text = self.subTitle;
}

- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
    [super setSelected:selected animated:animated];

    //1. If no subtitle, override current constraint
    if (!self.subTitle) {
        self.subtitleLabel.hidden = YES;
        self.titleLabelVerticalConstraint.constant = 0;
    }
}
@end

如何使用2标签制作自定义UITableViewCell，如果标签文本为空，另一个填充空间？

2 个答案: