我有一个 Xamarin IOS 应用程序，它每 10 秒获取一次用户位置，即使应用程序被终止也是如此。我让我们使用这个库：“https://jamesmontemagno.github.io/GeolocatorPlugin/”。
我想要的是：当应用程序关闭或打开并且用户位于特定位置时，我想显示本地通知。当应用程序关闭时，这甚至可能吗？我找不到这方面的信息，因为它总是关于远程通知。
【问题讨论】：
标签： xamarin.ios geolocation localnotification xamarin-forms-4
应在应用启动后立即通过将以下代码添加到AppDelegate 的FinishedLaunching 方法并设置所需的通知类型（UNAuthorizationOptions）来请求通知权限：
...
using UserNotifications;
...
public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
{
....
//after iOS 10
if(UIDevice.CurrentDevice.CheckSystemVersion(10,0))
{
UNUserNotificationCenter center = UNUserNotificationCenter.Current;
center.RequestAuthorization(UNAuthorizationOptions.Alert | UNAuthorizationOptions.Sound | UNAuthorizationOptions.UNAuthorizationOptions.Badge, (bool arg1, NSError arg2) =>
{
});
center.Delegate = new NotificationDelegate();
}
else if(UIDevice.CurrentDevice.CheckSystemVersion(8, 0))
{
var settings = UIUserNotificationSettings.GetSettingsForTypes(UIUserNotificationType.Alert| UIUserNotificationType.Badge| UIUserNotificationType.Sound,new NSSet());
UIApplication.SharedApplication.RegisterUserNotificationSettings(settings);
}
return true;
}
iOS 10 的新增功能，当应用程序在前台并触发通知时，它可以以不同的方式处理通知。通过提供 UNUserNotificationCenterDelegate 并实现 UserNotificationCentermethod，应用程序可以接管显示通知的责任。例如：
using System;
using ObjCRuntime;
using UserNotifications;
namespace workplat
{
public class NotificationDelegate:UNUserNotificationCenterDelegate
{
public NotificationDelegate()
{
}
public override void WillPresentNotification(UNUserNotificationCenter center, UNNotification notification, Action<UNNotificationPresentationOptions> completionHandler)
{
// Do something with the notification
Console.WriteLine("Active Notification: {0}", notification);
// Tell system to display the notification anyway or use
// `None` to say we have handled the display locally.
completionHandler(UNNotificationPresentationOptions.Alert|UNNotificationPresentationOptions.Sound);
}
public override void DidReceiveNotificationResponse(UNUserNotificationCenter center, UNNotificationResponse response, Action completionHandler)
{
// Take action based on Action ID
switch (response.ActionIdentifier)
{
case "reply":
// Do something
break;
default:
// Take action based on identifier
if (response.IsDefaultAction)
{
// Handle default action...
}
else if (response.IsDismissAction)
{
// Handle dismiss action
}
break;
}
// Inform caller it has been handled
completionHandler();
}
}
}
要在系统中创建和注册自定义操作，请使用以下代码：
public void RegisterNotification(long time)
{
UNUserNotificationCenter center = UNUserNotificationCenter.Current;
//creat a UNMutableNotificationContent which contains your notification content
UNMutableNotificationContent notificationContent = new UNMutableNotificationContent();
notificationContent.Title = "xxx";
notificationContent.Body= "xxxx";
notificationContent.Sound = UNNotificationSound.Default;
UNTimeIntervalNotificationTrigger trigger = UNTimeIntervalNotificationTrigger.CreateTrigger(time, false);
UNNotificationRequest request = UNNotificationRequest.FromIdentifier("FiveSecond", notificationContent, trigger);
center.AddNotificationRequest(request,(NSError obj) =>
{
});
}
当你调用这个方法时，例如：
RegisterNotification(20);//set the time you want to push notification
通知将在 20 秒后推送，如果您关闭应用程序。您可以在上传位置后添加此行。
我的demo已经上传到我的github了，大家可以下载参考：Demo Link.
您可以访问链接以获取更多信息和详细信息：MicroSoft Document
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