无法将UIActivityIndi​​catorView添加到UIButton子类

Question

我有一个UIButton子类，它将从Storyboard初始化，我没有使用Xib。我想以编程方式添加UIActivityIndicatorView。我的代码如下：import UIKit

class ResendConfirmButton: UIButton {

    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)!
        configActivityIndicator()
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        configStyling()

    }


    func configStyling() {
        let buttonLayer = CAShapeLayer()
        let buttonPath = UIBezierPath(roundedRect: bounds, byRoundingCorners: [UIRectCorner.bottomLeft, UIRectCorner.bottomRight], cornerRadii: CGSize(width: 2.0, height: 2.0))
        buttonLayer.path = buttonPath.cgPath
        buttonLayer.frame = bounds
        layer.mask = buttonLayer
    }

    var activityIndicator = UIActivityIndicatorView(activityIndicatorStyle: .white)

    func configActivityIndicator() {
        activityIndicator.center = CGPoint(x: bounds.midX, y: bounds.midY)
        addSubview(activityIndicator)
        activityIndicator.startAnimating()
    }


}

但由于某种原因，未添加活动指示符。我已尝试将configActivityIndicator移至layoutSubviews但这也不起作用。调用此方法的正确位置在哪里并保持按钮自包含？

Answer 1

在布局SubViews代码如下...

var activityIndicator = UIActivityIndicatorView()
activityIndicator = UIActivityIndicatorView(activityIndicatorStyle: UIActivityIndicatorViewStyle.White)
 activityIndicator.frame = CGRect(x: 0, y: 0, width: 50, height: 50)
            activityIndicator.startAnimating()
            self.addSubview(activityIndicator)

还有任何问题随时问我

Answer 2

只需在centerIndicatorInButton（）

中尝试此指标的更改位置即可

class ResendConfirmButton: UIButton {

var buttonText: String?
var activityIndicator: UIActivityIndicatorView!

func showLoading() {
    buttonText = self.titleLabel?.text
    self.setTitle("", forState: UIControlState.Normal)

    if (activityIndicator == nil) {
        activityIndicator = UIActivityIndicatorView()
      activityIndicator.hidesWhenStopped = true
      activityIndicator.color = UIColor.lightGrayColor()
    }

    // showSpinning
    activityIndicator.translatesAutoresizingMaskIntoConstraints = false
    self.addSubview(activityIndicator)
    centerIndicatorInButton()
    activityIndicator.startAnimating()
}

func hideLoading() {
    self.setTitle(buttonText, forState: UIControlState.Normal)
    activityIndicator.stopAnimating()
}

private func centerIndicatorInButton() {
    let xCenterConstraint = NSLayoutConstraint(item: self, attribute: .CenterX, relatedBy: .Equal, toItem: activityIndicator, attribute: .CenterX, multiplier: 1, constant: 0)
    self.addConstraint(xCenterConstraint)

    let yCenterConstraint = NSLayoutConstraint(item: self, attribute: .CenterY, relatedBy: .Equal, toItem: activityIndicator, attribute: .CenterY, multiplier: 1, constant: 0)
    self.addConstraint(yCenterConstraint)
}

}