按钮未完全绘制
按钮未完全绘制
提问于 2019-09-24 02:20:57
我有一个带有文本和图像的按钮。它在viewDidAppear中设置，然后在IBAction中更改属性标题。由于某些原因，按钮背景颜色在初始绘制时不能完全覆盖按钮。它会留下一条水平的白色长条。我发现，通过在IBAction中运行我的formatButton函数，随后按下的按钮会显示一个正确绘制的按钮。但是我不能让按钮的第一个加载视图看起来正确。有什么想法吗？
我发现，通过在IBAction中设置格式，它可以为将来的按钮绘制修复它，但是sendAction(.touchUpInside)甚至不能伪造它来修复绘制问题。(它确实像IBAction一样更改了按钮文本。)
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
formatButton(btn: searchTitlesButton)
formatButton(btn: searchPeopleButton)
formatButton(btn: searchCategoryButton)
searchTitlesButton.setTitle("Title", for: .normal)
searchPeopleButton.setTitle("Actor", for: .normal)
//searchCategoryButton.setTitle(categoryList[searchCategoryIndex], for: .normal)
let fullString = NSMutableAttributedString()
let imageAttachment = NSTextAttachment()
imageAttachment.image = UIImage(named:"DownArrow")
let imageString = NSAttributedString(attachment: imageAttachment)
fullString.append(NSAttributedString(string: categoryList[searchCategoryIndex]+" "))
fullString.append(imageString)
searchCategoryButton.setAttributedTitle(fullString, for: .normal)
formatButton(btn: searchCategoryButton)
postTableView.rowHeight = CGFloat(120)
}
@IBAction func searchCategoryButton(_ sender: Any) {
if searchCategoryIndex < categoryList.count - 1 {
searchCategoryIndex += 1
} else {
searchCategoryIndex = 0
}
// Going to try and make a formatted label with a string and image of a down arrow.
let fullString = NSMutableAttributedString()
let imageAttachment = NSTextAttachment()
imageAttachment.image = UIImage(named:"DownArrow")
let imageString = NSAttributedString(attachment: imageAttachment)
fullString.append(NSAttributedString(string: categoryList[searchCategoryIndex]+" "))
fullString.append(imageString)
searchCategoryButton.setAttributedTitle(fullString, for: .normal)
formatButton(btn: searchCategoryButton)
}
func formatButton(btn:UIButton) {
btn.layer.cornerRadius = 5
btn.layer.borderWidth = 1
btn.layer.borderColor = UIColor.black.cgColor
btn.setTitleColor(UIColor.white, for: .normal)
btn.titleLabel?.font = UIFont.systemFont(ofSize: 14, weight: UIFont.Weight.bold)
let gradientLayer = CAGradientLayer()
gradientLayer.frame = btn.bounds
let bottomColor = UIColor(red: CGFloat(25/255.0), green: CGFloat(113/255.0), blue: CGFloat(255/255.0), alpha: CGFloat(1.0))
gradientLayer.colors = [UIColor.white.cgColor, bottomColor.cgColor]
btn.layer.insertSublayer(gradientLayer, at: 0)
btn.clipsToBounds = true
}回答 1
Stack Overflow用户
回答已采纳
发布于 2019-09-24 04:43:33
背景渐变没有完全覆盖按钮的原因，可能是因为按钮的大小在设置属性标题时发生了变化。解决这个问题的最好方法是创建一个UIButton的子类，这样当按钮的边界改变时，你就可以更新你的自定义渐变层的框架。例如：
class GradientButton: UIButton {
private let gradientLayer = CAGradientLayer()
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setup()
}
private func setup() {
layer.cornerRadius = 5
layer.borderWidth = 1
layer.borderColor = UIColor.black.cgColor
setTitleColor(UIColor.white, for: .normal)
titleLabel?.font = UIFont.systemFont(ofSize: 14, weight: UIFont.Weight.bold)
let bottomColor = UIColor(red: CGFloat(25/255.0), green: CGFloat(113/255.0), blue: CGFloat(255/255.0), alpha: CGFloat(1.0))
gradientLayer.colors = [UIColor.white.cgColor, bottomColor.cgColor]
layer.insertSublayer(gradientLayer, at: 0)
clipsToBounds = true
}
override var bounds: CGRect {
didSet {
gradientLayer.frame = layer.bounds
}
}
}然后，在nib的情节提要中，您可以将按钮的类更改为GradientButton。它现在应该自动应用渐变样式，并在按钮的边界发生变化时更新框架。
我希望这对你有用。如果您仍然有问题，请让我知道。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/58068111
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