从服务发送通知 [英] Send notification from service
本文介绍了从服务发送通知的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我的 signalR 服务已经开始运行，现在我需要在收到消息时向用户发送通知.我编写了执行但未显示通知的通知代码.我的服务代码是:
I've got my signalR service working and now I need to send a notification to the user when a message is received. I wrote the notification code which is executed but no notification is displayed. My service code is:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Acr.UserDialogs;
using Android;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Support.V4.App;
using Android.Views;
using Android.Widget;
using Java.Lang;
using Java.Util.Concurrent;
using Microsoft.AspNet.SignalR.Client;
using Microsoft.AspNet.SignalR.Client.Transports;
namespace MyAndroid
{
[Service]
public class SignalRSrv : Service
{
private bool InstanceFieldsInitialized = false;
private string username = "";
private string firstname = "";
private string lastname = "";
private string company = "";
private string department = "";
private string section = "";
private void InitializeInstanceFields()
{
mBinder = new LocalBinder(this);
}
private Handler mHandler; // to display any received messages
private IBinder mBinder; // Binder given to clients
private SignalRSingleton mInstance;
private Notification notification = null;
public SignalRSrv()
{
if (!InstanceFieldsInitialized)
{
InitializeInstanceFields();
InstanceFieldsInitialized = true;
}
}
public override void OnCreate()
{
base.OnCreate();
mInstance = SignalRSingleton.getInstance();
mHandler = new Handler(Looper.MainLooper);
notification = RegisterForegroundService(); // here we set up the notification and start in foreground service
}
public override void OnDestroy()
{
base.OnDestroy();
}
public override IBinder OnBind(Intent intent)
{
//binder = new LocalBinder(this);
User MyUser = new User("", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "");
Bundle bundlee = intent.GetBundleExtra("TheBundle");
MyUser = bundlee.GetParcelable("MyUser") as User;
username = MyUser.Username;
firstname = MyUser.Firstname;
lastname = MyUser.Lastname;
company = intent.GetStringExtra("theSelectedCompany");
department = intent.GetStringExtra("theSelectedDepartment");
section = intent.GetStringExtra("theSelectedSection");
startSignalR(bundlee);
return mBinder;
}
private void startSignalR(Bundle bundle)
{
mInstance.setmHubConnection(username, firstname,lastname,company,department,section);
mInstance.setHubProxy();
try
{
// Connect the client to the hup
mInstance.mHubConnection.Start();
mInstance.mHubProxy.On("broadcastMessage", (string platform, string message) =>
{
try
{
showNotification(message, bundle, notification);
}
catch (System.Exception e)
{
var error = e.Message;
}
}
catch (System.Exception e) when (e is InterruptedException || e is ExecutionException)
{
//opps
var x = 1;
return;
}
}
public override StartCommandResult OnStartCommand(Intent intent, StartCommandFlags flags, int startId)
{
User MyUser = new User("", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "");
Bundle bundlee = intent.GetBundleExtra("TheBundle");
MyUser = bundlee.GetParcelable("MyUser") as User;
username = MyUser.Username;
firstname = MyUser.Firstname;
lastname = MyUser.Lastname;
company = intent.GetStringExtra("theSelectedCompany");
department = intent.GetStringExtra("theSelectedDepartment");
section = intent.GetStringExtra("theSelectedSection");
startSignalR(bundlee);
return StartCommandResult.Sticky;
}
Notification RegisterForegroundService()
{
var notification = new NotificationCompat.Builder(this)
.SetContentTitle("League Alert")
.SetContentText(Resources.GetString(Resource.String.notification_text))
.SetSmallIcon(Resource.Drawable.alert_box)
// Enlist this instance of the service as a foreground service
StartForeground(Constants.SERVICE_RUNNING_NOTIFICATION_ID, notification);
return notification;
}
public void showNotification(string message, Bundle bundle, Notification notification)
{
int count = 1;
try
{
Intent resultIntent = new Intent(this, typeof(Drawer));
// Pass some values to SecondActivity:
resultIntent.PutExtra("TheBundle", bundle);
// Construct a back stack for cross-task navigation:
Android.App.TaskStackBuilder stackBuilder = Android.App.TaskStackBuilder.Create(this);
stackBuilder.AddParentStack(Java.Lang.Class.FromType(typeof(Drawer)));
stackBuilder.AddNextIntent(resultIntent);
// Create the PendingIntent with the back stack:
PendingIntent resultPendingIntent =
stackBuilder.GetPendingIntent(0, PendingIntentFlags.UpdateCurrent);
NotificationManager notificationManager =
(NotificationManager)GetSystemService(Context.NotificationService);
notificationManager.Notify(Constants.SERVICE_RUNNING_NOTIFICATION_ID, notification);
}
catch (System.Exception e)
{
var error = e.Message;
}
}
private string CreateNotificationChannel()
{
if (Build.VERSION.SdkInt < BuildVersionCodes.O)
{
// Notification channels are new in API 26 (and not a part of the
// support library). There is no need to create a notification
// channel on older versions of Android.
return "";
}
var channelName = "My Messenger";
var channelDescription = "My Messenger Channel"; // GetString(Resource.String.channel_description);
var channel = new NotificationChannel("0", channelName, NotificationImportance.Default)
{
Description = channelDescription
};
var notificationManager = (NotificationManager)GetSystemService(NotificationService);
notificationManager.CreateNotificationChannel(channel);
return channelName;
}
}
public class LocalBinder : Binder
{
private readonly SignalRSrv outerInstance;
public LocalBinder(SignalRSrv outerInstance)
{
this.outerInstance = outerInstance;
}
public virtual SignalRSrv Service
{
get
{
// Return this instance of SignalRSrv so clients can call public methods
return outerInstance;
}
}
}
}
代码编译没有错误，我在代码中设置了断点以遵循流程，一切似乎都在正确执行，但没有出现通知.我错过了什么?
The code compiles with no errors and I set breakpoints in the code to follow the flow and all seems to be executing properly but no notification appears. What am I missing?
推荐答案
经过一些进一步的研究和实验，我终于弄清楚了.我现在工作的服务代码是:
After some further research and experimentation I was able to figure it out. My now working service code is:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Acr.UserDialogs;
using Android;
using Android.App;
using Android.Content;
using Android.Graphics;
using Android.OS;
using Android.Runtime;
using Android.Support.V4.App;
using Android.Views;
using Android.Widget;
using Java.Lang;
using Java.Util.Concurrent;
using Microsoft.AspNet.SignalR.Client;
using Microsoft.AspNet.SignalR.Client.Transports;
using Android.Net;
using Android.Media;
namespace My_Android_service
{
[Service]
public class SignalRSrv : Service
{
private bool InstanceFieldsInitialized = false;
private string username = "";
private string firstname = "";
private string lastname = "";
private string companny = "";
private string department = "";
private string section = "";
private int notifyid = 0;
private void InitializeInstanceFields()
{
mBinder = new LocalBinder(this);
}
private Handler mHandler; // to display any received messages
private IBinder mBinder; // Binder given to clients
private SignalRSingleton mInstance;
private Notification notification = null;
public SignalRSrv()
{
if (!InstanceFieldsInitialized)
{
InitializeInstanceFields();
InstanceFieldsInitialized = true;
}
}
public override void OnCreate()
{
base.OnCreate();
mInstance = SignalRSingleton.getInstance();
mHandler = new Handler(Looper.MainLooper);
}
public override void OnDestroy()
{
try
{
base.OnDestroy();
}
catch (System.Exception e)
{
var m = e.Message;
}
}
public override IBinder OnBind(Intent intent)
{
User MyUser = new User("", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "");
Bundle bundlee = intent.GetBundleExtra("TheBundle");
MyUser = bundlee.GetParcelable("MyUser") as User;
username = MyUser.Username;
firstname = MyUser.Firstname;
lastname = MyUser.Lastname;
company = intent.GetStringExtra("theSelectedCompany");
department = intent.GetStringExtra("theSelectedDepartment");
Section = intent.GetStringExtra("theSelectedSection");
startSignalR(bundlee);
return mBinder;
}
private void startSignalR(Bundle bundle)
{
mInstance.setmHubConnection(username, firstname,lastname,company,department,section);
mInstance.setHubProxy();
try
{
// Connect the client to the hub
mInstance.mHubConnection.Start();
// Setup the event handler for message received
mInstance.mHubProxy.On("broadcastMessage", (string platform, string message) =>
{
try
{
showNotification(message, bundle, notification);
}
catch (System.Exception e)
{
var error = e.Message;
}
});
}
catch (System.Exception e) when (e is InterruptedException || e is ExecutionException)
{
// handle any errors
var x = 1;
return;
}
}
public override StartCommandResult OnStartCommand(Intent intent, StartCommandFlags flags, int startId)
{
User MyUser = new User("", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "");
Bundle bundlee = intent.GetBundleExtra("TheBundle");
MyUser = bundlee.GetParcelable("MyUser") as User;
username = MyUser.Username;
firstname = MyUser.Firstname;
lastname = MyUser.Lastname;
company = intent.GetStringExtra("theSelectedCompany");
department = intent.GetStringExtra("theSelectedDepartment");
section = intent.GetStringExtra("theSelectedSection");
startSignalR(bundlee);
// Set up Notification
Notification notify = new Notification();
notify.Defaults = NotificationDefaults.Sound;
notify.Defaults = NotificationDefaults.Vibrate;
// Start Notification system, app will crash without this
StartForeground(Constants.SERVICE_RUNNING_NOTIFICATION_ID, notify);
return StartCommandResult.Sticky;
}
public void showNotification(string message, Bundle bundle, Notification notification)
{
try
{
// Activity to open when notification clicked, I'm not doing this yet.
//Intent intent = new Intent(this, typeof(Drawer)); //Activity you want to open
//intent.AddFlags(ActivityFlags.ClearTop);
//intent.PutExtra("TheBundle", bundle);
//var pendingIntent = PendingIntent.GetActivity(this, RandomGenerator(), intent, PendingIntentFlags.OneShot);
NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
.SetSmallIcon(Resource.Drawable.alert_box)
.SetContentTitle("Message Received")
.SetContentText(message)
//.SetSound(Settings.System.DefaultNotificationUri)
.SetVibrate(new long[] { 1000, 1000 })
.SetLights(Color.AliceBlue, 3000, 3000)
.SetAutoCancel(true);
//.SetContentIntent(pendingIntent);
// If this is oreo or above, we need a channel
NotificationChannel channel = null;
// Set sound to be used for notification
Android.Net.Uri alarmSound = RingtoneManager.GetDefaultUri(RingtoneType.Notification);
if (Build.VERSION.SdkInt >= BuildVersionCodes.O)
{
string channelId = "OML_Messenger"; //Context.GetString(Resource.String.default_notification_channel_id);
channel = new NotificationChannel(channelId, "Message Received", NotificationImportance.Default);
channel.Description = ("Message Received From Administrator");
notificationBuilder.SetSound(alarmSound);
notificationBuilder.SetChannelId(channelId);
}
// Connect to the notification system setup in OnStartCommandResult
NotificationManager notificationManager = (NotificationManager)Android.App.Application.Context.GetSystemService(Context.NotificationService);
// Create the channel, if not null
if (!channel == null)
{
notificationManager.CreateNotificationChannel(channel);
}
notifyid = RandomGenerator(); // Get a channel ID
// Send the noitification
notificationManager.Notify(notifyid, notificationBuilder.Build());
}
catch (System.Exception e)
{
var error = e.Message;
}
}
private int RandomGenerator()
{
return new Random().Next(int.MinValue, int.MaxValue);
}
}
public class LocalBinder : Binder
{
private readonly SignalRSrv outerInstance;
public LocalBinder(SignalRSrv outerInstance)
{
this.outerInstance = outerInstance;
}
public virtual SignalRSrv Service
{
get
{
// Return this instance of SignalRSrv so clients can call public methods
return outerInstance;
}
}
}
}
这篇关于从服务发送通知的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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