搜索视图控制器推送 VC 时，活动指示器不会出现在自定义 UIAlertView 的中心

Posted 2023-03-13

【中文标题】搜索视图控制器推送 VC 时，活动指示器不会出现在自定义 UIAlertView 的中心

【英文标题】：Activity Indicator not appears center on custom UIAlertView when search view controller push ups VC

【发布时间】：2019-01-09 06:16:49

【问题描述】：

我想在包含表格视图的 UIAlertViewController 上显示活动指示器，因此它可以正常工作，但第二种情况是当搜索控制器出现在 UIAlertViewController 的父级上时，活动指示器不会出现在 UIAlertViewController 的中心。

在将 searchVC 附加到父级之前附加图像

当 searchVC 添加到 Parent 时，然后

以下是活动指标代码

var actInd: UIActivityIndicatorView = UIActivityIndicatorView()

func startActivityIndicator() 
    self.view.isUserInteractionEnabled = false
    let loadingView: UIView = UIView()
    loadingView.frame =  CGRect(x: 0, y: 0, width: 80.0, height: 80.0)
    loadingView.center = self.view.center
    loadingView.backgroundColor = UIColor(red: 44/255, green: 44/255, blue: 44/255, alpha: 0.7)
    loadingView.clipsToBounds = true
    loadingView.layer.cornerRadius = 10
    actInd.frame = CGRect(x: 0, y: 0, width: 40.0, height: 40.0)
    actInd.style = .whiteLarge
    actInd.center = CGPoint(x: loadingView.frame.size.width / 2, y: loadingView.frame.size.height / 2)
    loadingView.addSubview(actInd)
    self.view.addSubview(loadingView)
    actInd.startAnimating()

func stopActivityIndicator() 
    self.view.isUserInteractionEnabled = true
    actInd.stopAnimating()
    let view = actInd.superview
    view?.removeFromSuperview()

我在UIViewController的扩展中添加了以上代码

【参考方案1】：

最后通过以下方式设置约束解决了

func startActivityIndicator() 
    self.view.isUserInteractionEnabled = false
    let loadingView: UIView = UIView()
    loadingView.translatesAutoresizingMaskIntoConstraints = false
    actInd.translatesAutoresizingMaskIntoConstraints = false
    self.view.addSubview(loadingView)
    loadingView.addSubview(actInd)
    loadingView.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true
    loadingView.centerYAnchor.constraint(equalTo: self.view.centerYAnchor).isActive = true
    loadingView.widthAnchor.constraint(equalToConstant: 80.0).isActive = true
    loadingView.heightAnchor.constraint(equalToConstant: 80.0).isActive = true
    loadingView.center = self.view.center
    loadingView.backgroundColor = UIColor(red: 44/255, green: 44/255, blue: 44/255, alpha: 0.7)
    loadingView.clipsToBounds = true
    loadingView.layer.cornerRadius = 10
    actInd.leadingAnchor.constraint(equalTo: loadingView.leadingAnchor).isActive = true
    actInd.trailingAnchor.constraint(equalTo: loadingView.trailingAnchor).isActive = true
    actInd.topAnchor.constraint(equalTo: loadingView.topAnchor).isActive = true
    actInd.bottomAnchor.constraint(equalTo: loadingView.bottomAnchor).isActive = true
    actInd.style = .whiteLarge
    actInd.center = CGPoint(x: loadingView.frame.size.width / 2, y: loadingView.frame.size.height / 2)
    actInd.startAnimating()