在搜索时,是否可以在UISearchBar中显示UIActivityIndicator?
iOS 13更新。
您可以在Swift 4+中使用以下扩展程序。 用法:
显示活动:
searchBar.isLoading = true
隐藏活动:
searchBar.isLoading = false
UISearchBar扩展程序
extension UISearchBar {
public var textField: UITextField? {
if #available(iOS 13.0, *) {
return self.searchTextField
} else {
let subViews = subviews.flatMap { $0.subviews }
guard let textField = (subViews.filter { $0 is UITextField }).first as? UITextField else {
return nil
}
return textField
}
}
public var activityIndicator: UIActivityIndicatorView? {
return textField?.leftView?.subviews.flatMap{ $0 as? UIActivityIndicatorView }.first
}
var isLoading: Bool {
get {
return activityIndicator != nil
} set {
if newValue {
if activityIndicator == nil {
let newActivityIndicator = UIActivityIndicatorView(activityIndicatorStyle: .gray)
newActivityIndicator.transform = CGAffineTransform(scaleX: 0.7, y: 0.7)
newActivityIndicator.startAnimating()
newActivityIndicator.backgroundColor = UIColor.white
textField?.leftView?.addSubview(newActivityIndicator)
let leftViewSize = textField?.leftView?.frame.size ?? CGSize.zero
newActivityIndicator.center = CGPoint(x: leftViewSize.width/2, y: leftViewSize.height/2)
}
} else {
activityIndicator?.removeFromSuperview()
}
}
}
}
可以的。
开始搜索时,创建一个活动指示器并使用 addSubview
方法将其添加为 UISearchBar
的子视图。当搜索完成后,使用 removeFromSuperview
方法从搜索栏中删除它。
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
//set frame for activity indicator
[searchBar addSubview: spinner];
[spinner startAnimating];
请参考此链接以获取另一种方式。
发现没有一种广告解决方案适用于iOS13...这里是我自己的解决方案,它对搜索栏进行了子类化,并应该更加稳健以供将来使用
class SearchBar: UISearchBar {
var activityIndicator: UIActivityIndicatorView?
var isLoading: Bool {
get {
return activityIndicator != nil
} set {
if newValue {
if activityIndicator == nil {
guard let leftView = searchTextField.leftView else {
return
}
let ai = UIActivityIndicatorView(style: .medium)
ai.frame = self.convert(leftView.frame, from: leftView.superview)
self.addSubview(ai)
ai.startAnimating()
leftView.isHidden = true
activityIndicator = ai
}
} else {
activityIndicator?.removeFromSuperview()
activityIndicator = nil
guard let leftView = searchTextField.leftView else {
return
}
leftView.isHidden = false
}
}
}
}