Question

我在Xamarin.Forms中有一个应用程序，我开发了一个仅在应用程序打开或最小化时才有效的服务。我添加了一些日志，即使应用程序关闭，服务也会继续运行，但我的部分代码在Portable上运行不会。

Code MainActivity

var alarmIntent = new Intent(context.ApplicationContext, typeof(Receiver.AlarmReceiver));
var broadcast = PendingIntent.GetBroadcast(context.ApplicationContext, 0, alarmIntent, PendingIntentFlags.NoCreate);
if (broadcast == null)
{
    var pendingIntent = PendingIntent.GetBroadcast(context.ApplicationContext, 0, alarmIntent, 0);
    var alarmManager = (AlarmManager)context.GetSystemService(Context.AlarmService);
    alarmManager.SetRepeating(AlarmType.ElapsedRealtimeWakeup, SystemClock.ElapsedRealtime(), 15000, pendingIntent);
}

代码警报接收器

[BroadcastReceiver]
class AlarmReceiver : BroadcastReceiver
{
    public override void OnReceive(Context context, Intent intent)
    {
        var backgroundServiceIntent = new Intent(context, typeof(ServiceBackground));
        context.StartService(backgroundServiceIntent);
    }
}

代码服务

[Service]
public class ServiceBackground : Service
{
    private const string TAG = "[ServiceBackground]";
    private bool _isRunning;
    private Context _context;
    private Task _task;

    public override IBinder OnBind(Intent intent)
    {
        return null;
    }

    public override void OnCreate()
    {
        _context = this;
        _isRunning = false;
        _task = new Task(RunServiceBackground);
    }

    public override StartCommandResult OnStartCommand(Intent intent, StartCommandFlags flags, int startId)
    {
        if (!_isRunning)
        {
            _isRunning = true;
            _task.Start();
        }
        return StartCommandResult.Sticky;
    }

    private void RunServiceBackground()
    {
        Log.Info(TAG, "StartCommandResult");

        Task.Run(() =>
        {
            try
            {
                Log.Info(TAG, "init background portable");
                var serviceOrdersSvc = new ServiceOrdersService();

                serviceOrdersSvc.BackgroundExecute()
                                .ContinueWith(itemResult => {
                                    if (!string.IsNullOrEmpty(itemResult.Result))
                                    {
                                        Log.Info(TAG, "itemResult");

                                    }
                                });
            }
            catch (Android.OS.OperationCanceledException ex)
            {
                Log.Info(TAG, $"ex msg: {ex.Message} | s: {ex.StackTrace}");
            }
            catch (Exception ex)
            {
                Log.Info(TAG, $"ex msg: {ex.Message} | s: {ex.StackTrace}");
            }
            finally
            {
                StopSelf();
            }

        });
    }

    public override void OnDestroy()
    {
        base.OnDestroy();
    }
}

代码可移植（此部分不起作用）

public async Task<string> BackgroundExecute()
{
    //insert sqllite
    await LogService.InsertLogAsync("init - BackgroundExecute");

    //get sqllite
    var list = await BackgroundTaskRequest.GetListAsync();
    var rtnBackground = "";

    if (list != null && list.Count > 0)
    {
        LogService.InsertLogAsync("list count: " + list.Count.ToString());

        await Task.Run(async () =>
        {
            foreach (var item in list)
            {
                //send information web-api
            }
        });
    }

    LogService.InsertLogAsync($"end rtn: {rtnBackground}");

    return rtnBackground;
}

我在这里缺少什么？

服务运行应用已关闭

0 个答案: