我在我的应用程序中使用推送通知服务。当应用程序在后台时，我能够在通知屏幕上看到通知(当我们从iOS设备顶部向下滑动时显示的屏幕)。但如果应用程序是在前台的委托方法
- (void)application:(UIApplication*)application didReceiveRemoteNotification:(NSDictionary*)userInfo
正在被调用，但通知屏幕上没有显示通知。
我想在通知屏幕上显示通知，不管应用程序是在后台还是前台。我厌倦了寻找解决办法。任何帮助都非常感激。
当前回答
Swift 5
1)使用UNUserNotificationCenterDelegate确认委托到AppDelegate 2)在didFinishLaunch中UNUserNotificationCenter.current().delegate = self 3)在AppDelegate中实现如下方法。
func userNotificationCenter(_ center: UNUserNotificationCenter,
willPresent notification: UNNotification,
withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
print("Push notification received in foreground.")
completionHandler([.alert, .sound, .badge])
}
就是这样!
其他回答
您可以创建自己的通知，模仿横幅警报。
一种方法是创建一个自定义的uiview，看起来像横幅，可以动画和响应触摸。考虑到这一点，你可以创建更好的横幅，甚至更多的功能。
或者你可以寻找一个api来帮你做这件事，并把它们作为podfile添加到你的项目中。
以下是我使用过的一些方法:
https://github.com/terryworona/TWMessageBarManager
https://github.com/toursprung/TSMessages
最好的方法是通过使用扩展AppDelegate: UNUserNotificationCenterDelegate在AppDelegate中添加UNUserNotificationCenterDelegate 该扩展告诉应用程序能够在使用时获得通知
并实现这个方法
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
completionHandler(.alert)
}
只有当应用程序在前台时，才会在委托上调用此方法。
最后的实现:
extension AppDelegate: UNUserNotificationCenterDelegate {
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
completionHandler(.alert)
}
}
要调用这个，你必须在AppDelegate中在didFinishLaunchingWithOptions中设置委托添加这一行
UNUserNotificationCenter.current().delegate = self
你可以修改
completionHandler(.alert)
与
completionHandler([.alert, .badge, .sound]))
Swift 5
1)使用UNUserNotificationCenterDelegate确认委托到AppDelegate 2)在didFinishLaunch中UNUserNotificationCenter.current().delegate = self 3)在AppDelegate中实现如下方法。
func userNotificationCenter(_ center: UNUserNotificationCenter,
willPresent notification: UNNotification,
withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
print("Push notification received in foreground.")
completionHandler([.alert, .sound, .badge])
}
就是这样!
iOS 14 +
下面这个答案有一个不同之处，.alert已弃用，使用.banner:
class AppDelegate: NSObject, UIApplicationDelegate, UNUserNotificationCenterDelegate {
func application(
_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil
) -> Bool {
UNUserNotificationCenter.current().delegate = self
return true
}
func userNotificationCenter(
_ center: UNUserNotificationCenter,
willPresent notification: UNNotification,
withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void
) {
completionHandler([.banner, .badge, .sound])
}
}
在你的应用委托中使用下面的代码
import UIKit
import UserNotifications
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate {
var currentToken: String?
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
application.registerForRemoteNotifications()
let center = UNUserNotificationCenter.current()
center.requestAuthorization(options: [.alert, .sound, .badge]) { (granted, error) in
// Enable or disable features based on authorization.
if granted == true
{
print("Allow")
UIApplication.shared.registerForRemoteNotifications()
}
else
{
print("Don't Allow")
}
}
UNUserNotificationCenter.current().delegate = self
return true
}
func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data){
let tokenParts = deviceToken.map { data -> String in
return String(format: "%02.2hhx", data)
}
let token = tokenParts.joined()
currentToken = token //get device token to delegate variable
}
public class var shared: AppDelegate {
return UIApplication.shared.delegate as! AppDelegate
}
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
completionHandler([.alert, .badge, .sound])
}
}
