应用程序在推送通知时重新加载单击Xamarin表单

Question

我已经在我的应用程序上实现了推送通知，它们工作得很好。我遇到的问题是，当我点击下拉菜单中的它们时，它们会立即重新加载应用程序。为了解决这个问题，我让应用程序创建了一个新的活动实例。这现在打开了一个新的页面，但当点击从这个新的页面返回时，它有同样的问题，并重新加载整个应用程序。

 [Service]
[IntentFilter(new[] { "com.google.firebase.MESSAGING_EVENT" })]

public class ForegroundMessages: FirebaseMessagingService
{


    const string TAG = "MyFirebaseMsgService";
    public override void OnMessageReceived(RemoteMessage message)
    {
        //Log.Debug(TAG, "From: " + message.From);
        //Log.Debug(TAG, "Notification Message Body: " + message.GetNotification().Body);
        base.OnMessageReceived(message);
        SendNotification(message.GetNotification().Body);
    }

    private void SendNotification(string body)
    {
        var intent = new Intent(this, typeof(MainActivity));
        intent.AddFlags(ActivityFlags.ClearTop);
       // var pendingIntent = PendingIntent.GetActivity(this, 0, intent, PendingIntentFlags.OneShot);

        Log.Debug(TAG, "Notification Message Body: " + body);

        // sends notification to view model
        MessagingCenter.Send((App)Xamarin.Forms.Application.Current, "Increase");

        Intent resultintent = new Intent(this,typeof(SecondActivity));

        TaskStackBuilder stackbuilder = TaskStackBuilder.Create(this);
        stackbuilder.AddParentStack(Java.Lang.Class.FromType(typeof(SecondActivity)));
        stackbuilder.AddNextIntent(resultintent);

        PendingIntent resultPendingIntent = stackbuilder.GetPendingIntent(0, (int)PendingIntentFlags.UpdateCurrent);

        var defaultSoundUri = RingtoneManager.GetDefaultUri(RingtoneType.Notification);
        var notificationBuilder = new NotificationCompat.Builder(this)
            .SetSmallIcon(Resource.Drawable.icon)
            .SetContentTitle("Notification")
            .SetContentText(body)
            .SetAutoCancel(true)
            .SetSound(defaultSoundUri)
            .SetContentIntent(resultPendingIntent);

        var notificationManager = NotificationManager.FromContext(this);
        notificationManager.Notify(0, notificationBuilder.Build());
    }


}

  [Activity(Label = "Notifications")]
public class SecondActivity:Activity
{

    protected override void OnCreate(Bundle bundle)
    {
        base.OnCreate(bundle);

        System.Diagnostics.Debug.WriteLine("this worked");
    }

}

Answer 1

你可以查看我的帖子，它展示了我是如何做到的，我还打开了一个表单页面。这篇文章有点长，但基本上有几件事：

• 我不使用第二个活动
• 我不将cleartop标志添加到mainactivityintent
• 我不使用TaskStackBuilder，而是只使用PendingIntent.GetActivity获取PendingIntent
• 然后，我在文章中通过将MainActivity的LaunchMode设置为LaunchMode.SingleTop，重写MainActivity中的OnNewIntent，然后检查Intent.HasExtras中设置的特殊String，以将该Intent与其他Intent区别开来，从而在文章中解决应用程序重新启动问题

如果以后你还有问题就告诉我。

private void SendNotification(string body)
{
    var intent = new Intent(this, typeof(MainActivity));
    intent.AddFlags(ActivityFlags.ClearTop);
   // var pendingIntent = PendingIntent.GetActivity(this, 0, intent, PendingIntentFlags.OneShot);
    intent.PutExtra("SomeSpecialKey", "some special value");

    Log.Debug(TAG, "Notification Message Body: " + body);

    if (Forms.IsInitialized) { // Ensure XF code has been initialized
        // sends notification to view model
        MessagingCenter.Send((App)Xamarin.Forms.Application.Current, "Increase");
    }

    PendingIntent pendingIntent = PendingIntent.GetActivity(Application.Context, 0, intent, PendingIntentFlags.UpdateCurrent | PendingIntentFlags.OneShot);

    var defaultSoundUri = RingtoneManager.GetDefaultUri(RingtoneType.Notification);
    var notificationBuilder = new NotificationCompat.Builder(this)
        .SetSmallIcon(Resource.Drawable.icon)
        .SetContentTitle("Notification")
        .SetContentText(body)
        .SetAutoCancel(true)
        .SetSound(defaultSoundUri)
        .SetContentIntent(pendingIntent);

    var notificationManager = NotificationManager.FromContext(this);
    notificationManager.Notify(0, notificationBuilder.Build());
}

则在MainActivity中：

[Activity(LaunchMode = LaunchMode.SingleTop, ....)]
public class MainActivity : FormsApplicationActivity {

    protected override void OnNewIntent(Intent intent) {
        if(intent.HasExtra("SomeSpecialKey")) {
            System.Diagnostics.Debug.WriteLine("\nIn MainActivity.OnNewIntent() - Intent Extras: " + intent.GetStringExtra("SomeSpecialKey") + "\n");
        }

        base.OnNewIntent(intent);
    }