ClipsToBounds在单元格中不起作用

Question

我有一个带自定义单元格的UITableView.每个单元格的结构都是这样的:我有contentView,在这个contentView中我有backView(简单的UIView有白色背景和角落半径16.0),在这个backView我有一个带有一些图片的imageView.

我想要的是让这个imageView走投无路(在他的父UIView - backView - 边框内).而且这种方式不起作用.

代码非常简单(来自ImageCell.swift):

    self.backView = UIView()
    self.backView.backgroundColor = UIColor.white
    self.backView.translatesAutoresizingMaskIntoConstraints = false
    self.backView.layer.cornerRadius = 16.0
    self.contentView.addSubview(backView)

    self.picture = UIImageView()
    self.picture.translatesAutoresizingMaskIntoConstraints = false
    self.picture.contentMode = UIViewContentMode.scaleAspectFill
    self.picture.backgroundColor = UIColor.gray
    self.picture.clipsToBounds = true
    self.backView.addSubview(picture)

    let constraintPicTop = NSLayoutConstraint(item: picture, attribute: .top, relatedBy: .equal, toItem: contentView, attribute: .topMargin, multiplier: 1.0, constant: -6)
    let constraintPicLeft = NSLayoutConstraint(item: picture, attribute: .left, relatedBy: .equal, toItem: backView, attribute: .leftMargin, multiplier: 1.0, constant: -8)
    let constraintPicRight = NSLayoutConstraint(item: picture, attribute: .right, relatedBy: .equal, toItem: backView, attribute: .rightMargin, multiplier: 1.0, constant: 8)
    constraintBottomPic = NSLayoutConstraint(item: picture, attribute: .bottom, relatedBy: .lessThanOrEqual, toItem: contentView, attribute: .topMargin, multiplier: 1.0, constant: 150)

我事先不知道图像的大小,因此在botForRowAt函数中更新了constraintBottomPic值.

并且它正在工作,除了这个图像没有走投无路(我相信它应该是).

(不幸的是,我不可能为UIImageView设置cornerRadius).

更新:找到解决方案.看来我必须直接在所有父视图中将'clipsToBounds'设置为true(在我的例子中是contentView和backView).

Answer 1

您应该设置clipsToBounds更高级别容器视图的属性(就像contentView您的单元格一样).