Develop Reference

In Unity, I want to change the scene and then change the text displayed, but the scene change always happens last

I'm a beginner and this is my first post here so please let me know if I could do anything better.
Using PUN 2 in Unity, I'm trying to return a connection error message when the user attempts to connect to a Photon server but fails.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement; //Library that provides utilities for scene management
using Photon.Pun; //Library for Photon, provides networking utilities
using Photon.Realtime; //Helps solve problems relating to matchmaking and fast communication
using UnityEngine.UI; //
public class MenuMan : MonoBehaviourPunCallbacks
{
public override void OnDisconnected(DisconnectCause cause) //Callback for when device fails to connect to server. Parameter 'cause' is the cause of this failure
{
Debug.Log("failed :("); // FOR DEBUGGING
Debug.Log(cause); //Prints in the console the cause of this connection failure
DisplayErrorMessage();
}
public Text Message;
public string MessageValue = " ";
public void DisplayErrorMessage() //Method that displays a connection error message to the user
{
SceneManager.LoadScene("Character Select Menu"); //Ensures user is on the Character Select menu
MessageValue = "AAAAAAA";
//Message.text = MessageValue;
Debug.Log(Message.text);
Debug.Log(MessageValue);
}
}
When I run this code, the text "AAAAA" flashes for a second, then disappears. Through testing I found out this is because the message displays first for some reason, and only after does the scene change thus resetting the text.
I tried using coroutines to delay MessageValue from being altered until the scene changed:
public override void OnDisconnected(DisconnectCause cause) //Callback for when device fails to connect to server. Parameter 'cause' is the cause of this failure
{
StartCoroutine(GoToCSM());
DisplayErrorMessage();
}
IEnumerator GoToCSM()
{
Debug.Log("cor started");
SceneManager.LoadScene("Character Select Menu")
yield return new WaitForSeconds(3);
DisplayErrorMessage();
Debug.Log("Done");
}
public Text Message; //Initialises a 'Text' type object, which will be set to the Connection fail message
static string MessageValue = " "; //Initialises a string which will be written to the 'text' component of the above object
public void DisplayErrorMessage() //Method that displays a connection error message to the user
{
MessageValue = "AAAAAAA"; //Writes the string to be displayed to MessageValue
Message.text = MessageValue; //Sets the above text to the 'text' component of the Message object, thus displaying it on the screen
}
However the coroutine never goes past the yield statement. It just stops at the yield statement and doesn't continue (even the Debug.Log("Done") doesn't get logged).
But when I tried switching some things round and put SceneManager.LoadScene("Character Select Menu") beneath the yield statement, that was executed just fine, as well as the debug statement below. I have no idea why this could be, and am very confused.
This was meant to be an extremely simple 10 minute task and I've wasted days trying to figure out what to do now. Any help would be extremely greatly appreciated. Thank you!

When switching scenes the object running the coroutines gets destroyed. Which results in it never executing the delayed code in the coroutines, this also applies when loading the same scene as you have currently loaded.
Unity reloads the whole scene, it resets everything!
This is also the reason why you see the text flashing for a few seconds. You set the text of some component in your scene, then unity reloads it and its reset.
SceneManager.LoadScene is not instant it just tells unity to start loading the Scene and then switching to it when ready.
Which by the way is not a very performant thing to do and should only be done when you need to really reset it.
If you want to pass values such as cause of disconnection from one scene to another you should use static variables.
These are not stored in objects(that get deleted on scene load). They are static and get saved when switching scenes.
It would help if you shared some more details about the structure of your project. That can help us find a solution that suits your needs.

Unity - My script stops working on Editor but works on my builds(android, ios)

Installed Unity Version is 2020.2.1f1
I'm developing an online multiplayer game using Unity. I have 2 different connection types; Http and Websocket(using Websocketsharp: https://github.com/sta/websocket-sharp, I've installed it using Nuget). Http get/post, Websocket connect/send/close works totally fine but when I call function (directly or by sending events) after response, most of the time my code inside that called function is not completed on editor(works fine on builds-android,ios). I'm not sure if this problem is related to http/websocket but it's related to online connection because I've experienced the same issue when I was developing a real-time multiplayer game using Unity & Gamesparks.
I can do basic functions like print etc. until I call one of the following functions loadscene, update UI, or call another function in same/different script(only first one of these works, everything after that won't run). Console doesn't show any error and game doesn't pause or crash. It runs on same fps but that part of the code won't continue. Other scripts/updates works fine. I've searched a lot but couldn't even find a related topic.
WebSocket Client:
void OnBattleResponse(object sender, MessageEventArgs messageEventArgs) {
string message = messageEventArgs.Data;
if (messageEventArgs.Data.Equals(Constants.WEBSOCKET_ERROR))
return;
var webSocketData = JsonUtility.FromJson<BattleResponseSerializable>(message);
switch (webSocketData.type) {
case 0:
seed = webSocketData.user1.seed;
opponentSeed = webSocketData.user2.seed;
_connectionManager.BattleGetStart(seed, opponentSeed);
break;
.
.
.
}
Connection Manager:
public void BattleGetStart(int userSeed, int opponentSeed) {
_gameManager.StartWave(userSeed, opponentSeed);
}
Game Manager
public void StartWave(int userSeed, int opponentSeed)
{
UserSeed = userSeed;
OpponentSeed = opponentSeed;
UserRandom = new System.Random(UserSeed);
OpponentRandom = new System.Random(OpponentSeed);
StartWaveTimer(); // After this nothing will be run, it's not related to startWaveTimer, any function that I've mentioned causes the same issue.
print("DOESN'T WORK"); // This doesn't work on Editor but works on builds
_spawner.ActivateSpawner(true); // doesn't work
}
I've found a trick to handle this situation but I didn't like it as a proper solution and don't wanna spend resources for Update calls. When I call function (directly or by sending events) after response, inside the called function I set bool to true and in Update call I call the necessary function when the bool is true and the code works totally fine.
---The Trick---
Game Manager
bool startWave;
public void StartWave(int userSeed, int opponentSeed)
{
UserSeed = userSeed;
OpponentSeed = opponentSeed;
UserRandom = new System.Random(UserSeed);
OpponentRandom = new System.Random(OpponentSeed);
startWave = true;
}
void Update() {
if (startWave) {
startWave = false;
StartWaveTimer();
print("WORKS"); // With this trick, it works on editor too.
_spawner.ActivateSpawner(true); // works
}
}
What can be the reason of my script working on builds but not on unity editor?
Thank you!

Advice for those who will experience that kind of issue:
As I've found out Unity is not Thread safe. Unity limits us on calling their API from another Thread, which causes this issue.
So you have to call your functions/methods from main thread instead of another thread.

Foreground services and repetitive tasks which need to be executed on time

I'm developing an app which basically performs some tasks on timer tick (in this case - searching for beacons) and sends results to the server. My goal was to create an app which does its job constantly in the background. Fortunately, I'm using logging all over the code, so when we started to test it we found that sometime later the timer's callback wasn't being called on time. There were some pauses which obviously had been caused by standby and doze mode. At that moment I was using a background service and System.Threading.Timer. Then, after some research, I rewrote the services to use Alarm Manager + Wake locks, but the pauses were still there. The next try was to make the service foreground and use it with a Handler to post delayed tasks and everything seemed to be fine while the device was connected to the computer. When the device is not connected to a charger those pauses are here again. The interesting thing is that we cannot actually predict this behavior. Sometimes it works perfectly fine and sometimes not. And this is really strange because the code to schedule it is pretty simple and straightforward:
...
private int scanThreadsCount = 0;
private Android.OS.Handler handler = new Android.OS.Handler();
private bool LocationInProgress
{
get { return Interlocked.CompareExchange(ref scanThreadsCount, 0, 0) != 0; }
}
public void ForceLocation()
{
if (!LocationInProgress) DoLocation();
}
private async void DoLocation()
{
Interlocked.Increment(ref scanThreadsCount);
Logger.Debug("Location is started");
try
{
// Location...
}
catch (Exception e)
{
Logger.Error(e, "Location cannot be performed due to an unexpected error");
}
finally
{
if (LocationInterval > 0)
{
# It's here. The location interval is 60 seconds
# and the service is running in the foreground!
# But in the screenshot we can see the delay which
# sometimes reaches 10 minutes or even more
handler.PostDelayed(ForceLocation, LocationInterval * 1000);
}
Logger.Debug("Location has been finished");
Interlocked.Decrement(ref scanThreadsCount);
}
}
...
Actually it can be ok, but I need that service to do its job strictly on time, but the callback is being called with a few seconds delay or a few minutes and that's not acceptable.
The Android documentation says that foreground services are not restricted by standby and doze mode, but I cannot really find the cause of that strange behavior. Why is the callback not being called on time? Where do these 10 minutes pauses come from? It's pretty frustrating because I cannot move further unless I have the robust basis. Does anybody know the reason of such a strange behavior or any suggestions how I can achieve the callback to be executed on time?
P.S. The current version of the app is here. I know, it's quite boring trying to figure out what is wrong with one's code, but there are only 3 files which have to do with that problem:
~/Services/BeaconService.cs
~/Services/BeaconServiceScanFunctionality.cs
~/Services/BeaconServiceSyncFunctionality.cs
The project was provided for those who would probably want to try it in action and figure it out by themselves.
Any help will be appreciated!
Thanks in advance

CPU is 100% at multithreading

First I've read all the posts here regarding this issue and I manged to progress a bit. However it seems I do need your help :)
I have a program with several threads, sometimes (not always) the CPU usage of the program is increasing up to 100% and never reduced until I shut down the program.
As I read in other similar posts, I ran the app using the visual studio (2012 - Ultimate).
I paused the app, and open the threads window.
There I pauses the threads until I've found the 4 threads which stuck the app.
The all refer to the same line of code (a call for constructor).
I checked the constructor inside and outside and couldn't find any loop which could cause it.
To be more careful I've added break point to almost every line of code and resume the app. None of them have been triggered.
This is the line of code:
public static void GenerateDefacementSensors(ICrawlerManager cm)
{
m_SensorsMap = new Dictionary<DefacementSensorType, DefacementSensor>();
// Create instance of all sensors
// For any new defacement sensor, don't forget to add an appropriate line here
// m_SensorsMap.add(DefacementSensorType.[Type], new [Type]Sensor())
try
{
if (m_SensorsMap.Count <= 0)
{
m_SensorsMap.Add(DefacementSensorType.BackgroundSensor, new BackgroundSensor());
m_SensorsMap.Add(DefacementSensorType.TaglinesSensor, new TaglinesSensor(cm.Database));
m_SensorsMap.Add(DefacementSensorType.SingleImageSensor, new SingleImageSensor());
}
}
catch (Exception)
{
Console.WriteLine("There was a problem initializing defacement sensors");
}
}
The second "m_SensorsMap.Add" is marked with green arrow, as I understand it, it means it's still waiting to the first line to finish.
By the way, the m_SensorsMap.Count value is 3.
How can I find the problem?
Is it a loop?
Or maybe a deadlock (not make sense because it shouldn't be 100% cpu, right?)
It's pointless to upload a code because this is a huge project.
I need more general help like how to debug?
Is it could something else than a loop?
Because it's a bug that returns every while and than I'm not closing the app until I found the problem :)
Thanks in advance!!
Edit:
The constructors:
public TaglinesSensor(IDatabase db)
{
m_DB = db;
}

I couldn't found the problem so I've changed the design on order not to call those constructors anymore.
Thanks for the guys who tried to help.
Shaul

determining the current link speed of WiFi in C#

I am writing a program that does one thing, it finds out the current link speed of the wifi connection and reports it to the user in real time. the problem I am having is that it does not seem to be able to find out the current link speed, only the max link speed of the device (300 Mbps). the reason I am writing this is that I have a problem where, periodically the link speed will drop drastically (down to 1-2 Mbps) and I want to be able to see when that happens. with this code it will simply give me the maximum speed that the adapter supports, not the current link speed of the connection.
private void update(object state)
{
System.Net.NetworkInformation.NetworkInterface[] nics = null;
nics = System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces();
long speed = 0;
string adapter = "";
foreach (System.Net.NetworkInformation.NetworkInterface net in nics)
{
if (net.Name.Contains("Wireless") || net.Name.Contains("WiFi") || net.Name.Contains("802.11") || net.Name.Contains("Wi-Fi"))
{
speed = net.Speed;
adapter = net.Name;
break;
}
}
string temp;
if (speed == 0)
{
temp = "There is currently no Wi-Fi connection";
}
else
{
temp = "Current Wi-Fi Speed: " + (speed / 1000000) + "Mbps on " + adapter;
}
if (label1.InvokeRequired)
{
SetTextCallback d = new SetTextCallback(update);
label1.Invoke(d, new object[] { temp });
}
else
{
label1.Text = temp;
}
}
this run by calling
System.Threading.Timer ticker = new System.Threading.Timer(update, label1, 0, 1000);
in the main method.

Considering that it literally took me the whole entire day to find what the solution to this was, I figured I'd at least show StackOverflow for future reference what I came across and what did and did not work for this question.
tl;dr: Scroll to the The Code section
What I found
Good ol' control panel
If you are looking for the really easy way to do this you can simply go and open Contol Panel. Depending on what version of Windows you are on (in my case I'm on Windows 8), the path to the page is Control Panel >> Network and Internet >> Network and Sharing Center and then you can click on the link next to "Connections: " which will give you a window that looks like what is below.
The current link speed is highlighted in red which in my case is 36.0 Mbps. Though, of course, this might not satisfy your original question if you were intending to integrate some code with the actual value.
WMI
With a mix of Googling and whatnot, I thought I might have found something in Windows Management Instrumentation.
Long story short, AFAIK, WMI does not have what we're looking for.
WMI, in short, is a giant object database (that
can also be queried through SQL) that allows you to query information about a
Windows machine such as process, disks, etc. In WMI, everything is
represented by a class with a series of instances each with a set of
properties.
Anyhow, WMI Explorer allows you to view all of this on your machine.
I (supposedly) found two classes on MSDN that might have the info on link speed but from WMI Explorer, there was nothing useful.
The first class, MSFT_NetAdapter, did not even show up in WMI Explorer on my machine.
The second class, Win32_NetworkAdapter, showed up in WMI Explorer, but the Speed property was still incorrect. The same network adapter was showing a value of 168000000 or 168 Mbps which is not right. Though I find this strange because there was already a MaxSpeed but it was blank.
Scratch WMI off the list.
Win32 P/Invoke
Yes, of course, the solution to everything is always calling unmanaged Win32 APIs using P/Invoke magic.
This is the route used to solve the problem.
Luckily, the IP_ADAPTER_ADDRESSES structure solves the problem. If you look at the MSDN page, it's a fairly large structure but what is important here is TransmitLinkSpeed which actually works.
Calling the GetAdaptersAddresses() function will return the actual structure.
Now, the actual C# P/Invoke code. Luckily, pinvoke.net already had interop for this function which I've added. This is all that was necessary.
The Code
Finally, here is your code patched up with the new P/Invoke black magic. I've made it work as a console application for demo purposes:
Using Statements:
using System;
using System.Threading;
Code:
class Program
{
private static void Main(string[] args)
{
Timer ticker = new Timer(Update, null, 0, 1000);
// Keep the main thread from dying
while (true)
{
Thread.Sleep(1000);
}
}
private static void Update(object state)
{
ulong speed = 0;
string adapter = "";
string[] nameSearches = { "Wireless", "WiFi", "802.11", "Wi-Fi" };
// The enum value of `AF_INET` will select only IPv4 adapters.
// You can change this to `AF_INET6` for IPv6 likewise
// And `AF_UNSPEC` for either one
foreach (IPIntertop.IP_ADAPTER_ADDRESSES net in IPIntertop.GetIPAdapters(IPIntertop.FAMILY.AF_INET))
{
bool containsName = false;
foreach (string name in nameSearches)
{
if (net.FriendlyName.Contains(name))
{
containsName = true;
}
}
if (!containsName) continue;
speed = net.TrasmitLinkSpeed;
adapter = net.FriendlyName;
break;
}
string temp;
if (speed == 0)
{
temp = "There is currently no Wi-Fi connection";
}
else
{
temp = string.Format("Current Wi-Fi Speed: {0} Mbps on {1}", (speed / 1000000.0), adapter);
}
Console.WriteLine(temp);
}
}
You are then going to be looking for the actual IPIntertop class that I updated. Since it's pretty big you can find it updated at pinvoke.net or on this PasteBin in case something goes down.
Bottom Line
Windows has a lot of APIs which are somewhat broken (WMI), can have a few "leaky abstractions" (.Net), or can be a pain to work with (Win32).
Sigh, that is a lot and I hope it helps.

I come accross the same issue, and need to get windows wifi link speed which is current negotiated.
and thanks to #Jaxrtech's WMI approach, that really works.
the correct class is CIM_NetworkAdapter(i'm using windows7), and query the speed column to get the current speed.
while wifi current negotiated speed is changing, this speed is changing too. i tested it, this matched ok.
select Description , DeviceID, Speed from CIM_NetworkAdapter
get:
D-Link DWA-140 RangeBooster N USB Adapter 17 285000000

Since no-one here mentioned it yet: why not use https://learn.microsoft.com/en-us/dotnet/api/system.net.networkinformation.networkinterface.speed?view=net-5.0#System_Net_NetworkInformation_NetworkInterface_Speed
This is, if the table on this site is correct included since .NET Framework 2.0 and seem to included in all other versions of .net including .net core.