I have this exception but I have been having difficulties solving it. I would be very pleased if anyone could help me. My aim is to show a message I received (from a broker) in a label field in xamarin. But unfortunately it doesn't work atm.
private async void onMessageReceived(MqttApplicationMessage msg) //async hinzugefügt
{
string msgEncoded = (Encoding.UTF8.GetString(msg.Payload));
double x = double.Parse(msgEncoded);
Console.WriteLine(msgEncoded);
x = Convert.ToDouble(tempWert.Text);
tempWert.Text = x.ToString();
//Überprüfung, ob Maschine zu warm
if (x >= 40)
{
await Task.Delay(5000);
Noti();
}
else
{
Console.WriteLine("Die Temperatur ist geringer als 40");
}
}
use MainThread
MainThread.BeginInvokeOnMainThread(() =>
{
// Code to run on the main thread
tempWert.Text = x.ToString();
});
Related
I'm trying to find out how the Bukkit version of WorldEdit handles brushes. I've been looking at the source code on GitHub, but I couldn't find anythig useful. I've tried to recreate the effect, but I can only get it to work when I'm in interaction reach of the target block.
This is about as close as it gets in the source code:
} else if (action == Action.RIGHT_CLICK_AIR) {
if (we.handleRightClick(player)) {
event.setCancelled(true);
}
}
(WorldEdit/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/WorldEditListener.java, line 143-147)
There are some other parts of code that get very close. I've also looked in /worldedit-core, but nothing there either.
Could someone help me here?
Edit: This is how I try to do it:
public static void onRightClick (PlayerInteractEvent event) {
if (event.getAction() == Action.RIGHT_CLICK_BLOCK) {
Location location = event.getClickedBlock().getLocation();
if (event.getItem() != null) {
if (event.getItem().getItemMeta().equals(ItemManager.wand.getItemMeta())) {
Player player = event.getPlayer();
player.getWorld().doStuff(location);
}
}
}
}
Edit #2: what I'm most curious about is: How does WE select the location to apply the brush if you are outside of interaction reach?
I needed to use BlockIterators for this. The final code looks like this:
public class BoomWandEvent implements Listener {
#EventHandler
public static void onRightClick (PlayerInteractEvent event) {
Player player = event.getPlayer();
if (event.getAction() == Action.RIGHT_CLICK_BLOCK || event.getAction() == Action.RIGHT_CLICK_AIR) {
if (player.getInventory().getItemInMainHand().equals(ItemManager.explosionWand)) {
Location eyePos = player.getEyeLocation();
BlockIterator raytracer = new BlockIterator(eyePos, 0.0D, player.getClientViewDistance() * 16);
while (raytracer.hasNext()) {
Location location = raytracer.next().getLocation();
if (player.getWorld().getBlockAt(location).getType() != Material.AIR && player.getWorld().getBlockAt(location).getType() != Material.CAVE_AIR && player.getWorld().getBlockAt(location).getType() != Material.VOID_AIR) {
player.getWorld().createExplosion(location, 4f);
return;
}
}
}
}
}
}
Thanks to Rogue for helping!
I really want to know how do I can update the position of the user in the map while the UWP app was running in bakground
Here is my code right now
private async void PinPoints()
{
//Pin point to the map
Windows.Devices.Geolocation.Geopoint position = await Library.Position();
double lat = position.Position.Latitude;
double lon = position.Position.Longitude;
//Geoposition alttest = await Library.Temp();
//alt = alttest.Coordinate.Altitude;
DependencyObject marker = Library.Marker(""
//+ Environment.NewLine + "Altitude " + alt
);
Display.Children.Add(marker);
Windows.UI.Xaml.Controls.Maps.MapControl.SetLocation(marker, position);
Windows.UI.Xaml.Controls.Maps.MapControl.SetNormalizedAnchorPoint(marker, new Point(0.5, 0.5));
Display.LandmarksVisible = true;
Display.ZoomLevel = 16;
Display.Center = position;
}
This function will pinpoint the current location for me but it will do only when user open this page due to I've put it in the public Map() {}
Current : Get the location when open map page and when I walk the map still be the same place
What I want : The position keep changing while I move on and also run on background (If application is close location data still changed)
Is there any code to solve this location problem if I have to add code where should I fix and what should I do?
Additional now I perform the background (Not sure is it work or not) by create the Window Runtime Component (Universal) with class like this
*I already put this project as the reference of the main one
namespace BackgroundRunning
{
public sealed class TaskBG : IBackgroundTask
{
BackgroundTaskDeferral _deferral = null;
Accelerometer _accelerometer = null;
Geolocator _locator = new Geolocator();
public void Run(IBackgroundTaskInstance taskInstance)
{
_deferral = taskInstance.GetDeferral();
try
{
// force gps quality readings
_locator.DesiredAccuracy = PositionAccuracy.High;
taskInstance.Canceled += taskInstance_Canceled;
_accelerometer = Windows.Devices.Sensors.Accelerometer.GetDefault();
_accelerometer.ReportInterval = _accelerometer.MinimumReportInterval > 5000 ? _accelerometer.MinimumReportInterval : 5000;
_accelerometer.ReadingChanged += accelerometer_ReadingChanged;
}
catch (Exception ex)
{
// Add your chosen analytics here
System.Diagnostics.Debug.WriteLine(ex);
}
}
void taskInstance_Canceled(IBackgroundTaskInstance sender, BackgroundTaskCancellationReason reason)
{
_deferral.Complete();
}
async void accelerometer_ReadingChanged(Windows.Devices.Sensors.Accelerometer sender, Windows.Devices.Sensors.AccelerometerReadingChangedEventArgs args)
{
try
{
if (_locator.LocationStatus != PositionStatus.Disabled)
{
try
{
Geoposition pos = await _locator.GetGeopositionAsync();
}
catch (Exception ex)
{
if (ex.HResult != unchecked((int)0x800705b4))
{
System.Diagnostics.Debug.WriteLine(ex);
}
}
}
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(ex);
}
}
public void Dispose()
{
if (_accelerometer != null)
{
_accelerometer.ReadingChanged -= accelerometer_ReadingChanged;
_accelerometer.ReportInterval = 0;
}
}
}
}
Your Solution :
Make 3 projects in your solution.
1> Background Task "references App_Code"
2> App_Code "contains calculations,mostly Backend Code"
3> Map(Main Project) "references App_Code"
Register a background Task to your project and specify the time interval after which it should run again
Scenario 1> App Open,User Requests Update
Trigger Your background Task from code behind.
Scenario 2> App Closed,Not Being Used
Run your background task!
So basically keep your backgroundTask simple(make it a class in whose run method you just call the proper App_Code Classes Method) and all calculations that you want to happen in the background keep them in App_Code. Also, if I am no wrong the minimum interval between which a background Task is triggered by itself cannot be set below 15 minutes.
For real-time you could look at SignalR ( can't help any further here)
I am trying to get a proof of concept running with akka.net. I am sure that I am doing something terribly wrong, but I can't figure out what it is.
I want my actors to form a graph of nodes. Later, this will be a complex graph of business objekts, but for now I want to try a simple linear structure like this:
I want to ask a node for a neighbour that is 9 steps away. I am trying to implement this in a recursive manner. I ask node #9 for a neighbour that is 9 steps away, then I ask node #8 for a neighbour that is 8 steps away and so on. Finally, this should return node #0 as an answer.
Well, my code works, but it takes more than 4 seconds to execute. Why is that?
This is my full code listing:
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using Akka;
using Akka.Actor;
namespace AkkaTest
{
class Program
{
public static Stopwatch stopwatch = new Stopwatch();
static void Main(string[] args)
{
var system = ActorSystem.Create("MySystem");
IActorRef[] current = new IActorRef[0];
Console.WriteLine("Initializing actors...");
for (int i = 0; i < 10; i++)
{
var current1 = current;
var props = Props.Create<Obj>(() => new Obj(current1, Guid.NewGuid()));
var actorRef = system.ActorOf(props, i.ToString());
current = new[] { actorRef };
}
Console.WriteLine("actors initialized.");
FindNeighboursRequest r = new FindNeighboursRequest(9);
stopwatch.Start();
var response = current[0].Ask(r);
FindNeighboursResponse result = (FindNeighboursResponse)response.Result;
stopwatch.Stop();
foreach (var d in result.FoundNeighbours)
{
Console.WriteLine(d);
}
Console.WriteLine("Search took " + stopwatch.ElapsedMilliseconds + "ms.");
Console.ReadLine();
}
}
public class FindNeighboursRequest
{
public FindNeighboursRequest(int distance)
{
this.Distance = distance;
}
public int Distance { get; private set; }
}
public class FindNeighboursResponse
{
private IActorRef[] foundNeighbours;
public FindNeighboursResponse(IEnumerable<IActorRef> descendants)
{
this.foundNeighbours = descendants.ToArray();
}
public IActorRef[] FoundNeighbours
{
get { return this.foundNeighbours; }
}
}
public class Obj : ReceiveActor
{
private Guid objGuid;
readonly List<IActorRef> neighbours = new List<IActorRef>();
public Obj(IEnumerable<IActorRef> otherObjs, Guid objGuid)
{
this.neighbours.AddRange(otherObjs);
this.objGuid = objGuid;
Receive<FindNeighboursRequest>(r => handleFindNeighbourRequest(r));
}
public Obj()
{
}
private async void handleFindNeighbourRequest (FindNeighboursRequest r)
{
if (r.Distance == 0)
{
FindNeighboursResponse response = new FindNeighboursResponse(new IActorRef[] { Self });
Sender.Tell(response, Self);
return;
}
List<FindNeighboursResponse> responses = new List<FindNeighboursResponse>();
foreach (var actorRef in neighbours)
{
FindNeighboursRequest req = new FindNeighboursRequest(r.Distance - 1);
var response2 = actorRef.Ask(req);
responses.Add((FindNeighboursResponse)response2.Result);
}
FindNeighboursResponse response3 = new FindNeighboursResponse(responses.SelectMany(rx => rx.FoundNeighbours));
Sender.Tell(response3, Self);
}
}
}
The reason of such slow behavior is the way you use Ask (an that you use it, but I'll cover this later). In your example, you're asking each neighbor in a loop, and then immediately executing response2.Result which is actively blocking current actor (and thread it resides on). So you're essentially making synchronous flow with blocking.
The easiest thing to fix that, is to collect all tasks returned from Ask and use Task.WhenAll to collect them all, without waiting for each one in a loop. Taking this example:
public class Obj : ReceiveActor
{
private readonly IActorRef[] _neighbours;
private readonly Guid _id;
public Obj(IActorRef[] neighbours, Guid id)
{
_neighbours = neighbours;
_id = id;
Receive<FindNeighboursRequest>(async r =>
{
if (r.Distance == 0) Sender.Tell(new FindNeighboursResponse(new[] {Self}));
else
{
var request = new FindNeighboursRequest(r.Distance - 1);
var replies = _neighbours.Select(neighbour => neighbour.Ask<FindNeighboursResponse>(request));
var ready = await Task.WhenAll(replies);
var responses = ready.SelectMany(x => x.FoundNeighbours);
Sender.Tell(new FindNeighboursResponse(responses.ToArray()));
}
});
}
}
This one is much faster.
NOTE: In general you shouldn't use Ask inside of an actor:
Each ask is allocating a listener inside current actor, so in general using Ask is A LOT heavier than passing messages with Tell.
When sending messages through chain of actors, cost of ask is additionally transporting message twice (one for request and one for reply) through each actor. One of the popular patterns is that, when you are sending request from A⇒B⇒C⇒D and respond from D back to A, you can reply directly D⇒A, without need of passing the message through whole chain back. Usually combination of Forward/Tell works better.
In general don't use async version of Receive if it's not necessary - at the moment, it's slower for an actor when compared to sync version.
I've made a big app for Skype called (Skype PWN4G3) one of its features are these lines of code:
//Control's
private void botOn_Click(object sender, EventArgs e)
{
if (toolStripLabel5.Text == "Not attached")
{
MessageBox.Show(notAttached, "Skype Pwnage - Info!", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
}
else
{
botStop = false;
skype.Attach(7, false);
skype.MessageStatus += new _ISkypeEvents_MessageStatusEventHandler(skype_MessageStatus);
botOn.Text = "Running";
botOn.Enabled = false;
botOff.Enabled = true;
}
}
private void botOff_Click(object sender, EventArgs e)
{
botStop = true;
botOn.Text = "Enable";
botOn.Enabled = true;
botOff.Enabled = false;
}
//Function
private void skype_MessageStatus(ChatMessage msg, TChatMessageStatus status)
{
if (botStop == true)
{
}
else
{
try
{
string command = msg.Body.Remove(0, trigger.Length).ToLower();
string[] lines = richTextBox4.Text.Split('\n');
foreach (string ln in lines)
{
string[] commands = ln.Split(':');
if (radioButton6.Checked == true)
{
if (command.Contains(commands[0]))
{
listBox2.Items.Add(DateTime.Now +"> "+ commands[0]);
skype.SendMessage(msg.Sender.Handle, string.Format(commands[1]));
break;
}
}
if (radioButton4.Checked == true)
{
if (command == commands[0])
{
listBox2.Items.Add(DateTime.Now + "> " + commands[0]);
skype.SendMessage(msg.Sender.Handle, string.Format(commands[1]));
break;
}
}
}
}
catch (Exception err0)
{
}
}
}
Now my issue is this code work's great and it will reply auto to a person if they say a certain word. But it's very odd acting.
If you start the bot with the Skype window minimized and let it do it's work it work's great until you stop then start it or change the radio button from "Exact" to "Contains" then the next time it runs it will reply 2 times, then if you do the above again it will reply 3 times and so on,
One other very odd problem is that once you open your Skype window and view the messages from your side it re-seneds them all again. Any idea why?
And one more extra if anyone know's how I can stop / start this correctly that would be fantastic. And if you know how to make it so this will not listen to messages from chat groups and only PM's that would be great because right now it will listen to chat then send to User.Handle unless I can make some way to have it send into chat where the message was sent.
1) reply 2, 3 and more times - it seems that the problem is in skype.MessageStatus += ... that is being called each time you click on botOn. Either call -= or make sure that event subscription happens only once.
2) sending message again: skype_MessageStatus is being called for one message two times - check SKYPE4COMLib.TChatMessageStatus cmsSending/cmsReceived - when the message is delivered and cmsSent/cmsRead when target user clicks and actually views the message - so all you need to do is to check the value of SKYPE4COMLib.TChatMessageStatus Status
3) to make difference between direct messages and chat groups test in your code
SKYPE4COMLib.ChatMessage pMessage;
if (pMessage.Chat.Members.Count == 2)
{
// process direct messages
}
else if(pMessage.Chat.Members.Count > 2)
{
// do whatever you want to do to process chat messages
}
I have a problem with my understanding of the standard actor library in Scala. In the code below I have created a simple swing, which basically should test if it is able to connect to a postgreSQL server. However it doesnt make it that far, I use Actors since the UI otherwise would freeze up while doing the work needed to connect to the database.
When er i use this line (meaning that I use actors instead of a single thread)
PostgresCheck ! new GetInfo()
The Swing will never be updated. However if I comment the line out and use the next three lines. (meaning the actors wont be used)
val result = PostgresCheck.checkPostgreSQL
if (result == "OK") pgText.background = GREEN else pgText.background = RED
pgText.text = result
The Swing will freeze but after about 25 seconds the swing will be updated.
import dbc.Database
import dbc.vendor.PostgreSQL
import java.awt.Dimension
import java.net.URI
import java.sql.Connection
import swing.event._
import swing._
import actors.Actor
import java.awt.Color._
import scala.actors.Actor._
case class Info(reply: String)
case class GetInfo()
object Example extends SimpleSwingApplication {
val pgButton = new Button("Check PostgreSQL")
val pgText = new TextArea("Not Checked Yet")
val pgPanel = new GridPanel(1, 2)
pgPanel.contents += pgButton
pgPanel.contents += pgText
def top = new MainFrame {
title = "StateChecker"
contents = pgPanel
}
listenTo(pgButton)
reactions += {
case e: ButtonClicked if (e.source.eq(pgButton)) => {
PostgresCheck ! new GetInfo()
//val result = PostgresCheck.checkPostgreSQL
//if (result == "OK") pgText.background = GREEN else pgText.background = RED
//pgText.text = result
}
}
val guiActor = new Actor {
def act() = {
loop {
react {
case e: String => {
val result = e
if (result == "OK") pgText.background = GREEN else pgText.background = RED
pgText.text = result
}
case e => println(e.toString)
}
}
}
}
guiActor.start
}
object PostgresCheck extends Actor {
def checkPostgreSQL() = {
try {
val db = new Database(myPgSQL)
val con: Connection = myPgSQL.getConnection // Freezes while doing this method
val statement = con.createStatement
if (statement.getResultSet.getMetaData.getColumnCount == 1) "OK"
else statement.getWarnings.toString
}
catch {
case e => e.toString
}
}
def act() = {
loop {
react {
case e: GetInfo => {
sender ! new Info(checkPostgreSQL)
}
}
}
}
start()
}
object myPgSQL extends PostgreSQL {
val uri = new URI("jdbc:postgresql://whatever.com")
val user = "1234"
val pass = "1234"
}
You are sending the message outside an actor, it seems. Try this:
Actor.actor { PostgresCheck ! new GetInfo() }
Not sure if it will help, but it is standard advise.
And, now that I think of it, to whom will the answer be sent? You are replying to the non-existent sender. I suppose you want the answer going to guiActor, but I don't see you doing so.
Okay here we go, the problem was related to the line
sender ! new Info(checkPostgreSQL)
It should actually have been
Example.guiActor! new Info(checkPostgreSQL)
For some reason related to the Actor library it actually suspends when waiting for the database connection, and wont return because of an unknown sender. For instance the following lines result in a printout of just a single line in console with "1".
val db = new Database(myPgSQL)
println("1")
// Freezes while doing this method
val con: Connection = myPgSQL.getConnection
println("2")
When changing the mentioned line, the code behave as expected.