标签: uitableviewautomaticdimension

所以,我的表视图显示图像.每个细胞基本上都是填满整个细胞的图像contentView.由于图像具有不同的宽高比,我需要我的单元格根据表格视图宽度和图像的纵横比调整其高度.我遵循了这个Ray Wenderlich教程但现在遇到了约束冲突.通过改变imageViews高度约束来调整图像的大小myImageViewHeight.constant = tableView.frame.width / aspectRatio

2016-06-16 13:56:25.823 MyApp[92709:5649464] 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. 
(
"<NSLayoutConstraint:0x7fbcdaf5c190 V:[UIImageView:0x7fbcdaf5c300(303)]>",
"<NSLayoutConstraint:0x7fbcdaf5b460 V:|-(0)-[UIImageView:0x7fbcdaf5c300]   (Names: '|':UITableViewCellContentView:0x7fbcdaf52230 )>",
"<NSLayoutConstraint:0x7fbcdaf5b4b0 V:[UIImageView:0x7fbcdaf5c300]-(0)-|   (Names: '|':UITableViewCellContentView:0x7fbcdaf52230 )>", …

我刚刚尝试了下面的代码行，但无法正常工作。我想知道如何以编程方式为页眉或页脚提供这种情况，可能正在使用自动布局，我不知道到底哪一个解决了我的问题。我正在使用 UITableViewHeaderFooterView 的 xib 文件。

如果有人解释我会很棒。

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()

    // Dynamic sizing for the footer view
    if let footerView = tableView.tableFooterView {
        let height = footerView.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize).height
        var footerFrame = footerView.frame

        if height != footerFrame.size.height {
            footerFrame.size.height = height
            footerView.frame = footerFrame
            tableView.tableFooterView = footerView
        }
    }

}

我有一个UITableViewCell固定在底部的描述标签，如下所示：

点击描述标签可在和numberOfLines之间切换：30

- (void)awakeFromNib {
    [super awakeFromNib];
    [self setupView];
}

-(void) setupView
{

    UITapGestureRecognizer * gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(toggleNumberOfLines)];
    self.jobDescriptionLabel.userInteractionEnabled = YES;
    [self.jobDescriptionLabel addGestureRecognizer:gestureRecognizer];
}

- (void) toggleNumberOfLines {
    if(self.jobDescriptionLabel.numberOfLines != 0){
        self.jobDescriptionLabel.numberOfLines = 0;
    }else{
        self.jobDescriptionLabel.numberOfLines = kNumberOfLines;
    }
    [self.jobDescriptionLabel sizeToFit];
    [self layoutIfNeeded];
}

当我点击标签时，行数确实发生了变化，但单元格不会扩展以容纳新的行数。我该如何解决？

折叠（默认）：

扩展：

阅读雷Wenderlich后指导的"自调整大小表格视图单元",以及这个问题和答案,我已经决定要问大家的帮助.

有一个程序创建的单元格:

import UIKit

class NotesCell: UITableViewCell {
lazy private var cellCaption: UILabel = {
    let label = UILabel()

    label.translatesAutoresizingMaskIntoConstraints = false
    label.font = UIFont.systemFont(ofSize: 20, weight: UIFont.Weight.medium)
    label.numberOfLines = 0
    label.lineBreakMode = .byWordWrapping

    return label
}()

func configure(with note: NotesModel) {
    cellCaption.text = note.name

    contentView.addSubview(cellCaption)
}

override func layoutSubviews() {
    super.layoutSubviews()

    NSLayoutConstraint.activate([
        cellCaption.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 8),
        cellCaption.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 8),
        cellCaption.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -8),
//            cellCaption.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -8),
cellCaption.bottomAnchor.constraint(greaterThanOrEqualTo: contentView.bottomAnchor, constant: -8)
            ])

// …