Question

在Xamarin.iOS项目中，我正在拦截推送通知，并希望在根据iOS项目中可访问的某些条件（存储的首选项）将其呈现给用户之前对其进行修改。如何将数据从iOS项目传递到Notification Service Extension，以及如何将其传递给Notification Service Extension？或者更准确地说，如何从iOS Notification Service Extension项目的Xamarin.Forms项目访问用户首选项？

我最有兴趣访问使用Xamarin.Essentials存储的用户首选项

这是Notification Service Extension的模板代码：

namespace NotifServiceExtension
{
    [Register("NotificationService")]
    public class NotificationService : UNNotificationServiceExtension
    {
        Action<UNNotificationContent> ContentHandler { get; set; }
        UNMutableNotificationContent BestAttemptContent { get; set; }

        protected NotificationService(IntPtr handle) : base(handle)
        {
            // Note: this .ctor should not contain any initialization logic.
        }

        public override void DidReceiveNotificationRequest(UNNotificationRequest request, Action<UNNotificationContent> contentHandler)
        {
            ContentHandler = contentHandler;
            BestAttemptContent = (UNMutableNotificationContent)request.Content.MutableCopy();

            // Modify the notification content here...
            var region = Preferences.Get("region_key", "error");   // I cannot access preferences this way   

             BestAttemptContent.Title = string.Format("{0}[modified]", BestAttemptContent.Title);          


            ContentHandler(BestAttemptContent);
        }

        public override void TimeWillExpire()
        {
            // Called just before the extension will be terminated by the system.
            // Use this as an opportunity to deliver your "best attempt" at modified content, otherwise the original push payload will be used.

            ContentHandler(BestAttemptContent);
        }
    }
}

Answer 1

最简单的方法是在Xamarin.Forms App类上公开一个方法。

在 App.xaml.cs 文件中添加这样的新方法：

public string GetUserRegion()
{
    return Preferences.Get("region_key", "error");
}

在您的NotificationService类中，您可以得到如下所示的区域：

var region = (Xamarin.Forms.Application.Current as App)?.GetUserRegion();

Xamarin.iOS将数据从iOS项目发送到Notification Service Extension

1 个答案: