ios 10+,Swift 3+ - 无法从 Singleton 实例中关闭 UIAlertController
ios 10+, Swift 3+ - Cannot dismiss UIAlertController from Singleton instance
我在 运行 上创建了一个叠加层,同时我 运行 将异步数据抓取到服务器,这样用户就不会继续按下 UI 中的按钮,直到数据抓取已经完成了。我已将该函数放入全局单例 class 中,并在传入布尔值时调用它来说明我是想显示还是隐藏。我可以让它显示,但我无法让它隐藏。这是代码:
class DataModel {
static let sharedInstance = DataModel()
func accessNetworkData(vc: UIViewController, params: [String:Any], wsURLPath: String, completion: @escaping (_ response: AnyObject) -> ()) {
DataModel.sharedInstance.toggleModalProgess(show: true)
// SHOW THE MODAL HERE ONCE THE DATA IS REQUESTED.
let url = URL(string: wsURLPath)!
let session = URLSession.shared
var request = URLRequest(url: url)
request.httpMethod = "POST"
do { request.httpBody = try JSONSerialization.data(withJSONObject: params, options: .prettyPrinted) } catch let error { print(error.localizedDescription) }
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in
DataModel.sharedInstance.toggleModalProgess(show: false)
// NOW SINCE THE NETWORK ACTIVITY IS DONE, HIDE THE UIALERTCONTROLLER
guard error == nil else {
print("WEB SERVICE ERROR <----------------------------<<<<<< " + wsURLPath)
print(error!)
let resp: [String: String] = [ "conn": "failed" ]
DispatchQueue.main.async { completion(resp as NSDictionary) }
return
}
guard let data = data else {
print("WEB SERVICE ERROR <----------------------------<<<<<< " + wsURLPath)
return
}
do {
if let parsedJSON = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] {
print("WEB SERVICE SUCCESS <----------------------------<<<<<< "+wsURLPath+" "+String(describing:params))
if let parsedResponseDict = parsedJSON["d"] as? NSDictionary {
DispatchQueue.main.async {
completion(parsedResponseDict)
}
}else if let parsedResponseArr = parsedJSON["d"] as? NSArray {
DispatchQueue.main.async {
completion(parsedResponseArr)
}
}else {
print("INVALID KEY <----------------------------<<<<<< " + wsURLPath)
DispatchQueue.main.async {
completion(parsedJSON as AnyObject)
}
}
}
} catch let error {
print("Error with JSON Serialization")
print(error.localizedDescription)
}
})
task.resume()
}
这里是我设置 UIALERTCONTROLLER
的地方
let modalAlert = UIAlertController(title: "Please Wait...", message: "Loading Data...", preferredStyle: UIAlertControllerStyle.alert)
let loadingIndicator = UIActivityIndicatorView(frame: CGRect(x: 10, y: 5, width: 50, height: 50))
func toggleModalProgess(show: Bool) -> Void {
print("toggleModalProgess: show = " + String(describing: show))
if (show) {
print("let's turn it on")
loadingIndicator.hidesWhenStopped = true
loadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray
loadingIndicator.startAnimating()
modalAlert.view.addSubview(loadingIndicator)
modalAlert.show()
}else {
print("let's turn it off")
modalAlert.hide()
}
}
private init() { }
}
现在是奇迹发生的扩展
public extension UIAlertController {
func show() {
let win = UIWindow(frame: UIScreen.main.bounds)
let vc = UIViewController()
vc.view.backgroundColor = .clear
win.rootViewController = vc
win.windowLevel = UIWindowLevelAlert + 1
win.makeKeyAndVisible()
vc.present(self, animated: true, completion: nil)
}
func hide() {
// HERE IS WHERE I NEED TO HIDE IT BUT I AM HAVING ISSUES
}
}
为了关闭UIAlertController
(它是UIViewController
的子类),调用dismiss
方法应该就足够了:
func hide() {
dismiss(animated: true, completion: nil)
}
它在我的示例项目中运行良好。
你应该做...
self.presentingViewController?.dismiss(animated: true, completion: nil)
希望对您有所帮助
我在 运行 上创建了一个叠加层,同时我 运行 将异步数据抓取到服务器,这样用户就不会继续按下 UI 中的按钮,直到数据抓取已经完成了。我已将该函数放入全局单例 class 中,并在传入布尔值时调用它来说明我是想显示还是隐藏。我可以让它显示,但我无法让它隐藏。这是代码:
class DataModel {
static let sharedInstance = DataModel()
func accessNetworkData(vc: UIViewController, params: [String:Any], wsURLPath: String, completion: @escaping (_ response: AnyObject) -> ()) {
DataModel.sharedInstance.toggleModalProgess(show: true)
// SHOW THE MODAL HERE ONCE THE DATA IS REQUESTED.
let url = URL(string: wsURLPath)!
let session = URLSession.shared
var request = URLRequest(url: url)
request.httpMethod = "POST"
do { request.httpBody = try JSONSerialization.data(withJSONObject: params, options: .prettyPrinted) } catch let error { print(error.localizedDescription) }
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in
DataModel.sharedInstance.toggleModalProgess(show: false)
// NOW SINCE THE NETWORK ACTIVITY IS DONE, HIDE THE UIALERTCONTROLLER
guard error == nil else {
print("WEB SERVICE ERROR <----------------------------<<<<<< " + wsURLPath)
print(error!)
let resp: [String: String] = [ "conn": "failed" ]
DispatchQueue.main.async { completion(resp as NSDictionary) }
return
}
guard let data = data else {
print("WEB SERVICE ERROR <----------------------------<<<<<< " + wsURLPath)
return
}
do {
if let parsedJSON = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] {
print("WEB SERVICE SUCCESS <----------------------------<<<<<< "+wsURLPath+" "+String(describing:params))
if let parsedResponseDict = parsedJSON["d"] as? NSDictionary {
DispatchQueue.main.async {
completion(parsedResponseDict)
}
}else if let parsedResponseArr = parsedJSON["d"] as? NSArray {
DispatchQueue.main.async {
completion(parsedResponseArr)
}
}else {
print("INVALID KEY <----------------------------<<<<<< " + wsURLPath)
DispatchQueue.main.async {
completion(parsedJSON as AnyObject)
}
}
}
} catch let error {
print("Error with JSON Serialization")
print(error.localizedDescription)
}
})
task.resume()
}
这里是我设置 UIALERTCONTROLLER
的地方 let modalAlert = UIAlertController(title: "Please Wait...", message: "Loading Data...", preferredStyle: UIAlertControllerStyle.alert)
let loadingIndicator = UIActivityIndicatorView(frame: CGRect(x: 10, y: 5, width: 50, height: 50))
func toggleModalProgess(show: Bool) -> Void {
print("toggleModalProgess: show = " + String(describing: show))
if (show) {
print("let's turn it on")
loadingIndicator.hidesWhenStopped = true
loadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray
loadingIndicator.startAnimating()
modalAlert.view.addSubview(loadingIndicator)
modalAlert.show()
}else {
print("let's turn it off")
modalAlert.hide()
}
}
private init() { }
}
现在是奇迹发生的扩展
public extension UIAlertController {
func show() {
let win = UIWindow(frame: UIScreen.main.bounds)
let vc = UIViewController()
vc.view.backgroundColor = .clear
win.rootViewController = vc
win.windowLevel = UIWindowLevelAlert + 1
win.makeKeyAndVisible()
vc.present(self, animated: true, completion: nil)
}
func hide() {
// HERE IS WHERE I NEED TO HIDE IT BUT I AM HAVING ISSUES
}
}
为了关闭UIAlertController
(它是UIViewController
的子类),调用dismiss
方法应该就足够了:
func hide() {
dismiss(animated: true, completion: nil)
}
它在我的示例项目中运行良好。
你应该做...
self.presentingViewController?.dismiss(animated: true, completion: nil)
希望对您有所帮助