个性化网站定制前端跟后端哪个就业难

概述

每种方法都是独立的，可以根据应用的需求单独使用。例如，如果应用的主要功能是跟踪用户的地理位置，则可以仅使用后台定位；若是为了保持应用在后台运行以完成特定任务（比如上传数据），则可以考虑申请后台时间；而播放无声音乐更适合那些需要长时间在后台运行且与音频播放相关的应用。其它的酌情考虑。

sevice

    public class XXXService{#region 音乐private static AVAudioPlayer? _audioPlayer;private static AVAudioSession? _audioSession;public static void StartBackgroundAudio(){// 初始化音频会话_audioSession = AVAudioSession.SharedInstance();_audioSession.SetCategory(AVAudioSessionCategory.Playback, AVAudioSessionCategoryOptions.MixWithOthers| AVAudioSessionCategoryOptions.AllowBluetoothA2DP| AVAudioSessionCategoryOptions.DefaultToSpeaker);_audioSession.SetActive(true, out _);// 加载无声音频文件var audioUrl = NSBundle.MainBundle.GetUrlForResource("silent", "mp3");_audioPlayer = new AVAudioPlayer(audioUrl, "mp3", out _);_audioPlayer.NumberOfLoops = -1; // 循环_audioPlayer.Volume = 0;_audioPlayer.Play();}public static void StopBackgroundAudio(){_audioPlayer?.Stop();_audioPlayer = null;_audioSession?.SetActive(false, out _);}#endregion#region 定位private static CLLocationManager _locationManager;public static void StartLocationUpdates(){_locationManager = new CLLocationManager();_locationManager.DesiredAccuracy = 100; // 根据需求调整精度/*_locationManager.DistanceFilter = 5;*/_locationManager.RequestAlwaysAuthorization();_locationManager.AllowsBackgroundLocationUpdates = true;_locationManager.PausesLocationUpdatesAutomatically = false;_locationManager.StartUpdatingLocation();}public static void StopLocationUpdates(){_locationManager?.StopUpdatingLocation();_locationManager = null;}#endregion#region 申请后台任务public static IDisposable RequestBackgroundTime(){// 申请后台时间var disposable=Observable.Interval(TimeSpan.FromSeconds(28)).Subscribe(_ =>{var taskid = UIApplication.SharedApplication.BeginBackgroundTask(() => { //处理你的任务});UIApplication.SharedApplication.EndBackgroundTask(taskid);});return disposable;}#endregion}

使用

在AppDelegate里：

public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
{OvernightMonitoringService.StartLocationUpdates();
}