C# OS.Handler类代码示例

        public override View OnCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState)
        {
            View rootView = inflater.Inflate(Resource.Layout.user_detail, container, false);

            if (_user != null) {
                ((TextView)rootView.FindViewById (Resource.Id.user_name)).Text = $"{_user.FirstName} {_user.LastName}";
                ((TextView)rootView.FindViewById (Resource.Id.mail_header)).Text = $"[Email]";
                ((TextView)rootView.FindViewById (Resource.Id.user_mail)).Text = _user.Email;
                ((TextView)rootView.FindViewById (Resource.Id.phone_header)).Text = $"[Telefon]";
                ((TextView)rootView.FindViewById (Resource.Id.user_phone)).Text = _user.Phone;
                ((TextView)rootView.FindViewById (Resource.Id.cell_header)).Text = $"[Mobil]";
                ((TextView)rootView.FindViewById (Resource.Id.user_cell)).Text = _user.Cell;

                var imageView = (ImageView)rootView.FindViewById (Resource.Id.user_image);

                Handler handler = new Handler (Context.MainLooper);
                Task.Run (() => {
                    var imageBitmap = ((ImageService)ServiceLocator.Current.GetInstance<ImageService>()).GetUserPicture(_user);
                    Runnable runnable = new Runnable (() => {
                        imageView.SetImageBitmap (imageBitmap);
                    });
                    handler.Post (runnable);
                });
            }
            return rootView;
        }

 public WidgetProvider()
 {
     // Start the worker thread
     workerThread = new HandlerThread (ThreadWorkerName);
     workerThread.Start();
     workerQueue = new Handler (workerThread.Looper);
 }

        public void BeginGeofencing(object sender, EventArgs eventArgs)
        {
            if (!apiClient.IsConnected) {
                var myHandler = new Handler ();
                myHandler.Post (() => {
                    Android.Widget.Toast.MakeText (this, "Google API Not Connected. Try Again.", Android.Widget.ToastLength.Long).Show ();
                });
                return;
            }

            try {
                if (connectedGeofences.Count >= 1) {
                    LocationServices.GeofencingApi.AddGeofences(apiClient, getGeofencingRequest(), getGeofencePendingIntent()).SetResultCallback(this);
                    string geofenceAnnounce = "Geofences Active At The Following Locations:\n";
                    foreach (ROMPGeofence geofName in connectedGeofences) {
                        geofenceAnnounce += geofName.Id + "\n";
                    }
                    var myHandler = new Handler ();
                    myHandler.Post (() => {
                        Android.Widget.Toast.MakeText (this, geofenceAnnounce, Android.Widget.ToastLength.Long).Show ();
                    });
                    FindViewById<Button>(Resource.Id.btnBegin).Visibility = ViewStates.Invisible;
                    FindViewById<TextView>(Resource.Id.lblConfirm).SetText("A record that you have checked-in will be made in the log of your education activity for this ROMP rotation when this device enters a 1km radius surrounding the facility of your ROMP rotation.", TextView.BufferType.Normal);
                    geofenceRequestIntent = PendingIntent.GetService (this, 0,
                        new Intent (this, Java.Lang.Class.FromType (typeof(GeofenceTransitionsIntentService))),
                        PendingIntentFlags.UpdateCurrent);
                } else {
                    FindViewById<Button>(Resource.Id.btnBegin).Visibility = ViewStates.Invisible;
                    FindViewById<TextView>(Resource.Id.lblConfirm).SetText("No Rotations Available, Please Try Within Your Scheduled Rotation Dates", TextView.BufferType.Normal);
                }
            } catch (SecurityException securityEx) {
                logSecurityException (securityEx);
            }
        }

 public SkiaView(Activity context) : base(context)
 {
     _context = context;
     SkiaPlatform.Initialize();
     Holder.AddCallback(this);
     _handler = new Handler(context.MainLooper);
 }

        protected override void OnCreate(Bundle savedInstanceState) {
            base.OnCreate(savedInstanceState);
            
            var pos = 0;
            if (Intent.Extras != null)
                pos = Intent.Extras.GetInt("pos");

            var birds = Resources.GetStringArray(Resource.Array.birds);
            var imgs = Resources.ObtainTypedArray(Resource.Array.birds_img);
            var resId = imgs.GetResourceId(pos, -1);

            Title = birds[pos];
            Window.RequestFeature(WindowFeatures.ActionBarOverlay);
            var color = new ColorDrawable(Color.Black);
            color.SetAlpha(128);
            ActionBar.SetBackgroundDrawable(color);
            ActionBar.SetDisplayHomeAsUpEnabled(true);
            _handler = new Handler();

            var imageView = new ImageView(this);
            imageView.SetScaleType(ImageView.ScaleType.CenterInside);
            imageView.SetImageResource(resId);
            imageView.Click += (sender, args) =>
                {
                    ActionBar.Show();
                    HideActionBarDelayed(_handler);
                };
            SetContentView(imageView);
            Window.SetBackgroundDrawableResource(Android.Resource.Color.BackgroundDark);
        }

		private void Peer_PeerConnected (object sender, PeerConnectedEventArgs args)
		{
			using (var h = new Handler (Looper.MainLooper))
				h.Post (() => {
					textView.Text = args.PeerId;
				});
		}

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

            mPreview = new Preview (this);

            RequestWindowFeature(WindowFeatures.NoTitle);
            Window.AddFlags (WindowManagerFlags.Fullscreen);

            SetContentView (Resource.Layout.CustomCameraLayout);

            FrameLayout preview = (FrameLayout)FindViewById (Resource.Id.camera_preview);
            preview.AddView (mPreview);

            mPicture = new PictureCallback ();

            //////////////////////////////////////
            Handler mHandler = new Handler ();///
            ////////////////////////////////////

            Button captureButton = FindViewById<Button> (Resource.Id.button_capture);
            captureButton.Click += (sender, e) => {

                System.Console.WriteLine("About to call take picture");
                mCamera.TakePicture(null, null, mPicture);
                System.Console.WriteLine("After TakePicture");

                Toast.MakeText(this, "Saving picture...", ToastLength.Long).Show();

                mHandler.PostDelayed(launchConfirmActivity,1000); //ideally this would be done through asynchronous methods, but this temporary fix will have to do for now
            };

            View controllers = FindViewById<RelativeLayout> (Resource.Id.CameraControls_layout);
            controllers.BringToFront();
        }

		protected override void OnLayout (bool changed, int l, int t, int r, int b)
		{
			using (var h = new Handler (Looper.MainLooper)) {
				h.Post (() => {
					double width = base.Context.FromPixels ((double)(r - l));
					double height = base.Context.FromPixels ((double)(b - t));
					var size = new Size (width, height);

					var msw = MeasureSpec.MakeMeasureSpec (r - l, MeasureSpecMode.Exactly);
					var msh = MeasureSpec.MakeMeasureSpec (b - t, MeasureSpecMode.Exactly);
					_nativeView.Measure (msw, msh);
					_nativeView.Layout (0, 0, r - l, b - t);

					//			if (size != _previousSize) {
					var layout = _viewCell.View as Layout<Xamarin.Forms.View>;
					if (layout != null) {
						layout.Layout (new Rectangle (0, 0, width, height));
						layout.ForceLayout ();
						FixChildLayouts (layout);
						_isLaidOut = true;
					}
					_previousSize = size;
				});
			}
			//			}
		}

 protected void RunOnMainThread(Action action)
 {
     Handler handler = new Handler(Looper.MainLooper);
     handler.Post(action);
     handler.Dispose();
     handler = null;
 }

        //
        // Marker related listeners.
        //
        public bool OnMarkerClick(Marker marker)
        {
            // This causes the marker at Perth to bounce into position when it is clicked.
            if (marker.Equals(mPerth)) {
                Handler handler = new Handler ();
                long start = SystemClock.UptimeMillis ();
                Projection proj = mMap.Projection;
                Point startPoint = proj.ToScreenLocation(PERTH);
                startPoint.Offset(0, -100);
                LatLng startLatLng = proj.FromScreenLocation(startPoint);
                long duration = 1500;

                IInterpolator interpolator = new BounceInterpolator();

                Runnable run = null;
                run = new Runnable (delegate {
                        long elapsed = SystemClock.UptimeMillis () - start;
                        float t = interpolator.GetInterpolation ((float) elapsed / duration);
                        double lng = t * PERTH.Longitude + (1 - t) * startLatLng.Longitude;
                        double lat = t * PERTH.Latitude + (1 - t) * startLatLng.Latitude;
                        marker.Position = (new LatLng(lat, lng));

                        if (t < 1.0) {
                            // Post again 16ms later.
                            handler.PostDelayed(run, 16);
                        }
                });
                handler.Post(run);
            }
            // We return false to indicate that we have not consumed the event and that we wish
            // for the default behavior to occur (which is for the camera to move such that the
            // marker is centered and for the marker's info window to open, if it has one).
            return false;
        }

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

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);

            // Get our button from the layout resource,
            // and attach an event to it
            Button button = FindViewById<Button>(Resource.Id.button1);
            button.Click += button_Click;

            Button button2 = FindViewById<Button>(Resource.Id.button2);
            button2.Click += button2_Click;

            LogOut.Action += LogOut_Action;

            MessHander = new Handler(Msg =>
            {
                FindViewById<TextView>(Resource.Id.textView1).Append(Msg.Obj.ToString() + "\n");

            });


            client = new ClientInfo(GetString(Resource.String.ServerIP), int.Parse(GetString(Resource.String.ServerPort)), int.Parse(GetString(Resource.String.ServerRegPort)), int.Parse(GetString(Resource.String.MinPort)), int.Parse(GetString(Resource.String.MaxPort)), int.Parse(GetString(Resource.String.ResCount)), GetString(Resource.String.MAC));
            client.ConToServer();
            client.ClientDataIn += client_ClientDataIn;
            client.ClientConnToMe += client_ClientConnToMe;
            client.ClientDiscon += client_ClientDiscon;

          
        }

 public void OnClick(View v)
 {
     Handler h = new Handler();
     h.Post(() => {
         this.Img.StartAnimation(this.AniSet);
     });
 }

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);
            SetContentView(Resource.Layout.Main);

            progress1 = FindViewById<CircleProgressBar>(Resource.Id.progress1);
            progress2 = FindViewById<CircleProgressBar>(Resource.Id.progress2);
            progressWithArrow = FindViewById<CircleProgressBar>(Resource.Id.progressWithArrow);
            progressWithoutBg = FindViewById<CircleProgressBar>(Resource.Id.progressWithoutBg);

            progress2.SetColorSchemeResources(Android.Resource.Color.HoloGreenLight);

            progressWithArrow.SetColorSchemeResources(Android.Resource.Color.HoloOrangeLight);
            progressWithoutBg.SetColorSchemeResources(Android.Resource.Color.HoloRedLight);

            handler = new Handler();
            for (int i = 0; i < 10; i++)
            {
                int finalI = i;
                handler.PostDelayed(() =>
                {
                    if (finalI * 10 >= 90)
                    {
                        progress2.Visibility = ViewStates.Invisible;
                    }
                    else
                    {
                        progress2.Progress = finalI * 10;
                    }
                }, 1000 * (i + 1));
            }
        }

		public override void OnCreate()
		{
			base.OnCreate();
			Log.Info(TAG, "OnCreate: the service is initializing.");

			timestamper = new UtcTimestamper();
			handler = new Handler();

			// This Action is only for demonstration purposes.
			runnable = new Action(() =>
							{
								if (timestamper == null)
								{
									Log.Wtf(TAG, "Why isn't there a Timestamper initialized?");
								}
								else
								{
									string msg = timestamper.GetFormattedTimestamp();
									Log.Debug(TAG, msg);
									Intent i = new Intent(Constants.NOTIFICATION_BROADCAST_ACTION);
									i.PutExtra(Constants.BROADCAST_MESSAGE_KEY, msg);
									Android.Support.V4.Content.LocalBroadcastManager.GetInstance(this).SendBroadcast(i);
									handler.PostDelayed(runnable, Constants.DELAY_BETWEEN_LOG_MESSAGES);
								}
							});
		}

 //--------------------------------------------------------------
 // CONSTRUCTORS
 //--------------------------------------------------------------
 public BluetoothManager()
 {
     _deviceAddress = string.Empty;
     _handler = new MyHandler ();
     _bluetoothAdapter = BluetoothAdapter.DefaultAdapter;
     _state = StateEnum.None;
 }