我在ServerCommunication类中有一个静态getData()方法可以从后台队列中调用此方法.
//ServerCommunication.swift
import UIKit
import Foundation
class ServerCommunication
{
class func getData(url: String,sessionId: String) -> ServerResponse {
//server communication code goes here
}
}
func populateData() {
DispatchQueue.global(qos: .background).async {
let response = ServerCommunication.getData(url: URL,sessionId: "")
}
}
任何人都可以解释对线程执行有什么影响或者我可能需要将ServerCommunication类定义为Singleton？
getData() static class executed multiple times when calling from background queue
#Edit1更多解释
当我尝试在发生推送通知时打开特定的viewController时发生此问题.我正在使用一个名为FAPanelController的第三方库,它分别接受一个中心,左右viewController.
代码示例：
@available(iOS 10.0,*)
func userNotificationCenter(_ center: UNUserNotificationCenter,didReceive response: UNNotificationResponse,withCompletionHandler completionHandler: @escaping () -> Void) {
//Now I want to open a viewController
if let panel = self.window?.rootViewController as? FAPanelController
{
let centerNavVC = storyboard.instantiateViewController(withIdentifier: "HomeViewController") as! UINavigationController
let vc = centerNavVC.topViewController as! HomeViewController
panel.center(centerNavVC,afterThat: {
//HomeViewController has a method populateData() in viewWillAppear()
})
}
}
解决方法
您可以使用Closures
class ServerCommunication
{
class func getData(url: String,sessionId: String,success: @escaping ((_ responSEObject: ServerResponse?) -> Void)) {
//server communication code goes here
success(serverData) // serverData is a server response
}
}
func populateData() {
ServerCommunication.getData(url: "",sessionId: "",success: { (response) in
// You can handle response here
print(response)
})
}
