ios - 滚动后 UITableViewCell 内的 UIView 中的渐变发生了变化

问题描述

我已经UIView在我的UITableViewCell. 在第一次加载时一切正常，但在滚动后，渐变颜色会再次加载，并且每次都会改变位置而不是实际设置条件。这是我实现渐变颜色的代码：

我该怎么办？

添加渐变层

func gradient(frame:CGRect,colors: [CGColor]) -> CAGradientLayer {
    let layer = CAGradientLayer()
    layer.frame = frame
    layer.startPoint = CGPoint(x: 1.0, y: 0.0)
    layer.endPoint = CGPoint(x: 0.0, y: 1.0)
    layer.locations = [0.5,0.35]
    layer.colors = colors
    return layer
}

UITableViewCell 类

class AllOfferlistCell: UITableViewCell {

    @IBOutlet weak var lbltitle: UILabel!
    @IBOutlet weak var lblPopular: UILabel!
    @IBOutlet weak var VwPercentage: UIView!   
}

表视图 cellForRowAtindexPath

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! AllOfferlistCell

    cell.lbltitle.text = "Index \(indexPath.row)"

    if self.DataArray[indexPath.row].Flag == "1"{

        cell.VwPercentage.layer.insertSublayer(gradient(frame: cell.VwPercentage.bounds, colors: [UIColor.red.cgColor,UIColor.white.cgColor]), at: 1)
        cell.lblPopular.text = "POPULAR"

    }else{

        cell.VwPercentage.layer.insertSublayer(gradient(frame: cell.VwPercentage.bounds, colors: [UIColor.blue.cgColor,UIColor.white.cgColor]), at: 1)
        cell.lblPopular.text = "50% OFF"
    }

    return cell
}

输出：

第一次加载

滚动后

标签： iosswiftuitableviewcagradientlayer

解决方案

创建如下自定义视图

@IBDesignable class TriangleGradientView: UIView {
    @IBInspectable var topColor: UIColor = UIColor.red {
        didSet {
            setGradient()
        }
    }
    @IBInspectable var bottomColor: UIColor = UIColor.blue {
        didSet {
            setGradient()
        }
    }
    
    override class var layerClass: AnyClass {
        return CAGradientLayer.self
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        setGradient()
    }
    
    private func setGradient() {
        (layer as! CAGradientLayer).colors = [topColor.cgColor, bottomColor.cgColor]
        (layer as! CAGradientLayer).startPoint = CGPoint(x: 1.0, y: 0.0)
        (layer as! CAGradientLayer).endPoint = CGPoint(x: 0.0, y: 1.0)
        (layer as! CAGradientLayer).locations = [0.5,0.35]
    }

}

采用

在界面生成器中将 customclass 设置VwPercentage为TriangleGradientView

将VwPercentage类型更改为TriangleGradientView.

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! AllOfferlistCell
    cell.lbltitle.text = "Index \(indexPath.row)"
    if self.DataArray[indexPath.row].Flag == "1"{
        cell.VwPercentage.topColor = .red
        cell.lblPopular.text = "POPULAR"
    }else{
        cell.VwPercentage.topColor = .blue
        cell.lblPopular.text = "50% OFF"
    }
    cell.VwPercentage.bottomColor = .white
    return cell
}

ios - 滚动后 UITableViewCell 内的 UIView 中的渐变发生了变化

问题描述

解决方案

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