Develop Reference

Can I create a pointer to poll a float from any source?

Is there a way to access all the different types of object inherited from the same class using the same reference in an object without hard-coding it?
I'm developing on unity and I want to add a module in my game that could watch any particular float in a GameObject to then change another float in another GameObject once it reaches a certain value.
As an example: A "Trigger" Object/Module which set the value of Hunger=1 in a brain Object when the value of Fullness<0.5 is reached in a stomach Object.
As I'll have a big number of possible combinations I don't want to hardcode it by creating a daughter of the Trigger Class for each of them.
My initial idea was to use pointers that would be directed to the good floats to watch/change upon initialization. But apparently, we can't use unsafe code inside iterators (IEnumerator) so I'm not sure how to poll the value of Fullness.
To give an example of what I would like :
public Class Trigger{
private float* ToPoll;
private float* ToChange;
public void SetTrigger(float* poll, float* change){
ToPoll = poll;
ToChange = change;
// the loop would be a IEnumerator, not a litteral loop
while(*ToPoll < 0.5f){
sleep(0.1)
}
*ToChange = 1f
}
}
void Main(){
Trigger trigger1, trigger2;
trigger1.SetTrigger(&Stomach.fullness, &Brain.hunger)
trigger2.SetTrigger(&Sun.activityLevel, &Earth.radiationLevel)
// ^ Literally any float from any object
}
Do you have any ideas how to or better ways to implement it?

Expanding on the answer from #kara, the following code implements independent Stomach and Brain objects, and uses Being to wire them up.
What Being knows about Stomach:
it has a NeedsFoodEvent
What Being knows about Brain
there is a OnRaiseIsHungryEvent (i.e. a "hungry" signal -- who cares where it came from)
it has a IsHungryEvent
Keep in mind that in a real implementation there would likely be other objects listening for those events. e.g. maybe you have an emotion system that would switch to "hangry" and a goal-based AI that would switch to food-seeking mode. Neither system would need to be aware of the other, but both could respond to signals from the Brain. In this trivial implementation the Being responds to the Stomach signal and both notifies and responds to the Brain.
The important take-away from this is not the specific method of raising and responding to events (in this case the default .Net mechanism) but the fact that neither object knows anything about the internals of the other (see the different implementations of HumanStomach and ZombieStomach) and instead the connection is wired up at a more appropriate level (Being in this case). Also note the reliance on interfaces, which allows us to do things like create hybrid beings (i.e. pairing a ZombieBrain with a HumanStomach).
Code was written/tested with .Net Core CLI as a console app, but it should be compatible with most any version of .Net > 3.5.
using System;
using System.Linq;
using System.Threading;
namespace so_example
{
public class Program
{
static void Main(string[] args)
{
var person1 = new Being("Human 1", new HumanBrain(), new HumanStomach());
var zombie1 = new Being("Zombie 1", new ZombieBrain(), new ZombieStomach());
var hybrid1 = new Being("Hybrid 1", new ZombieBrain(), new HumanStomach());
var hybrid2 = new Being("Hybrid 2", new HumanBrain(), new ZombieStomach());
Console.WriteLine("Hit any key to exit");
Console.ReadKey();
}
}
public class HungryEventArgs : EventArgs
{
public string Message { get; set; }
}
public interface IStomach
{
event EventHandler<HungryEventArgs> NeedsFoodEvent;
}
public class Stomach : IStomach
{
public event EventHandler<HungryEventArgs> NeedsFoodEvent;
protected virtual void OnRaiseNeedsFoodEvent(HungryEventArgs e)
{
EventHandler<HungryEventArgs> handler = NeedsFoodEvent;
if (handler != null)
{
handler(this, e);
}
}
}
public class HumanStomach : Stomach
{
private Timer _hungerTimer;
public HumanStomach()
{
_hungerTimer = new Timer(o =>
{
// only trigger if breakfast, lunch or dinner (24h notation)
if (new [] { 8, 13, 19 }.Any(t => t == DateTime.Now.Hour))
{
OnRaiseNeedsFoodEvent(new HungryEventArgs { Message = "I'm empty!" });
}
else
{
Console.WriteLine("It's not mealtime");
}
}, null, 1000, 1000);
}
}
public class ZombieStomach : Stomach
{
private Timer _hungerTimer;
public ZombieStomach()
{
_hungerTimer = new Timer(o =>
{
OnRaiseNeedsFoodEvent(new HungryEventArgs { Message = "Need brains in stomach!" });
}, null, 1000, 1000);
}
}
public interface IBrain
{
event EventHandler<HungryEventArgs> IsHungryEvent;
void OnRaiseIsHungryEvent();
}
public class Brain : IBrain
{
public event EventHandler<HungryEventArgs> IsHungryEvent;
protected string _hungryMessage;
public void OnRaiseIsHungryEvent()
{
EventHandler<HungryEventArgs> handler = IsHungryEvent;
if (handler != null)
{
var e = new HungryEventArgs
{
Message = _hungryMessage
};
handler(this, e);
}
}
}
public class HumanBrain : Brain
{
public HumanBrain()
{
_hungryMessage = "Need food!";
}
}
public class ZombieBrain : Brain
{
public ZombieBrain()
{
_hungryMessage = "Braaaaaains!";
}
}
public class Being
{
protected readonly IBrain _brain;
protected readonly IStomach _stomach;
private readonly string _name;
public Being(string name, IBrain brain, IStomach stomach)
{
_stomach = stomach;
_brain = brain;
_name = name;
_stomach.NeedsFoodEvent += (s, e) =>
{
Console.WriteLine($"{_name}: {e.Message}");
_brain.OnRaiseIsHungryEvent();
};
_brain.IsHungryEvent += (s, e) =>
{
Console.WriteLine($"{_name}: {e.Message}");
};
}
}
}
Some Notes
To provide some output, I faked things in the 2 IStomach implementations. The HumanStomach creates a timer callback in the constructor which fires every 1 second and checks if the current hour is a meal hour. If it is, it raises the NeedsFoodEvent. The ZombieStomach also uses a callback every 1 second, but it just fires the NeedsFoodEvent every time. In a real Unity implementation you'd likely trigger the even based on some event from Unity -- an action the player took, after some preset amount of time, etc.

I'm not quite sure, what you want to do, but it sounds like you want to add triggers to you objects. In my understanding a trigger should be a delegate in this case.
Here an example how to define a delegate-type and add a list of triggers to your Brain-class.
Every brain can now have different triggers. I setup two derived brains to show you how to work with it:
public class TestBrain
{
private static int NextId = 1;
public TestBrain(List<MyTrigger> triggers)
{
this.Triggers = triggers;
this.Id = NextId++;
}
public int Id { get; private set; }
public int Hunger { get; set; }
public int StomachFullness { get; set; }
public List<MyTrigger> Triggers { get; private set; }
public void FireTriggers()
{
foreach (MyTrigger t in this.Triggers)
{
t.Invoke(this);
this.StomachFullness = 100;
}
}
public delegate void MyTrigger(TestBrain b);
}
public class HumanBrain : TestBrain
{
static readonly List<MyTrigger> defaultHumanTriggers = new List<MyTrigger>()
{
b => { if (b.StomachFullness < 50) { b.Hunger = 1; Console.WriteLine("{0} is hungry..", b.Id); } }
};
public HumanBrain() : base(defaultHumanTriggers)
{
}
}
public class RobotBrain : TestBrain
{
static readonly List<MyTrigger> defaultRobotTriggers = new List<MyTrigger>()
{
b => { if (b.StomachFullness < 50) { Console.WriteLine("{0} ignores hunger only want's some oil..", b.Id); } }
};
public RobotBrain() : base(defaultRobotTriggers)
{
}
}
static void Main()
{
// Create some test-data
List<TestBrain> brains = new List<TestBrain>()
{
new HumanBrain(),
new HumanBrain(),
new RobotBrain(),
new HumanBrain(),
};
Console.WriteLine(" - - - Output our Testdata - - -");
foreach (TestBrain b in brains)
{
Console.WriteLine("Status Brain {0} - Stomachfulness: {1} Hunger: {2}", b.Id, b.StomachFullness, b.Hunger);
}
Console.WriteLine(" - - - Empty stomachs - - -");
foreach (TestBrain b in brains)
{
b.StomachFullness = 0;
}
Console.WriteLine(" - - - Fire triggers - - -");
foreach (TestBrain b in brains)
{
b.FireTriggers();
}
Console.WriteLine(" - - - Output our Testdata - - -");
foreach (TestBrain b in brains)
{
Console.WriteLine("Status Brain {0} - Stomachfulness: {1} Hunger: {2}", b.Id, b.StomachFullness, b.Hunger);
}
}

Bubbling events from child to parent (overal progress)

I have a problem which i don't know how to solve.
I have some classes (Processors) that fires an event with progress information ( Percentage of how far it is). There are multiple processors that do this and the top Processor (Engine) which calls them all needs to send information to the end user on its progress.
If i don't know beforehand how many items will be processed by each processor how can i give the user some good feedback on how far the process is?
Take a look at the following simplified example
NetFiddle
class Program {
static void Main(string[] args) {
var p = new Program();
p.Run();
}
private void Run() {
var engine = new Engine();
engine.UpdateProgress += Engine_UpdateProgress;
engine.Process();
Console.ReadLine();
}
private void Engine_UpdateProgress(object sender, UpdateProgressEventArgs e) {
Console.WriteLine($"{e.UpdateDateTime} - Caller: {e.Caller}, Percentage: {e.Percentage}");
}
}
public class Engine {
private readonly ProcessorA _processorA;
private readonly ProcessorB _processorB;
private readonly ProcessorC _processorC;
private readonly ProcessorD _processorD;
public event EventHandler<UpdateProgressEventArgs> UpdateProgress;
public Engine() {
_processorA = new ProcessorA();
_processorB = new ProcessorB();
_processorC = new ProcessorC();
_processorD = new ProcessorD();
//Handle events
_processorA.UpdateProgress += ProcessorA_UpdateProgress;
_processorB.UpdateProgress += ProcessorA_UpdateProgress;
_processorC.UpdateProgress += ProcessorA_UpdateProgress;
_processorD.UpdateProgress += ProcessorA_UpdateProgress;
}
private void ProcessorA_UpdateProgress(object sender, UpdateProgressEventArgs e) {
OnUpdateProgress(e);
}
public void Process() {
_processorA.Process();
_processorB.Process();
_processorC.Process();
_processorD.Process();
}
protected virtual void OnUpdateProgress(UpdateProgressEventArgs e) {
UpdateProgress?.Invoke(this, e);
}
}
public class ProcessorA : Processor {
private readonly ProcessorA_A _processorA_A;
public ProcessorA() {
_processorA_A = new ProcessorA_A();
//Handle events
_processorA_A.UpdateProgress += ProcessorA_A_UpdateProgress;
}
public void Process() {
_processorA_A.Process();
}
private void ProcessorA_A_UpdateProgress(object sender, UpdateProgressEventArgs e) {
OnUpdateProgress(e);
}
}
public class ProcessorB : Processor {
public void Process() {
for (int i = 0; i <= 100; i++) {
var args = new UpdateProgressEventArgs() { Caller = nameof(ProcessorB), Percentage = i, UpdateDateTime = DateTime.Now};
//Do some work
Thread.Sleep(r.Next(50,250));
OnUpdateProgress(args);
}
}
}
public class ProcessorC : Processor {
public void Process() {
for (int i = 0; i <= 100; i++) {
var args = new UpdateProgressEventArgs() { Caller = nameof(ProcessorC), Percentage = i, UpdateDateTime = DateTime.Now };
//Do some work
Thread.Sleep(r.Next(50, 250));
OnUpdateProgress(args);
}
}
}
public class ProcessorD : Processor {
public void Process() {
for (int i = 0; i <= 100; i++) {
var args = new UpdateProgressEventArgs() { Caller = nameof(ProcessorD), Percentage = i, UpdateDateTime = DateTime.Now };
//Do some work
Thread.Sleep(r.Next(50, 250));
OnUpdateProgress(args);
}
}
}
public class ProcessorA_A : Processor {
public void Process() {
for (int i = 0; i <= 100; i++) {
var args = new UpdateProgressEventArgs() { Caller = nameof(ProcessorA_A), Percentage = i, UpdateDateTime = DateTime.Now };
//Do some work
Thread.Sleep(r.Next(50, 250));
OnUpdateProgress(args);
}
}
}
public class Processor : IProcessor {
protected Random r = new Random();
public event EventHandler<UpdateProgressEventArgs> UpdateProgress;
protected virtual void OnUpdateProgress(UpdateProgressEventArgs e) {
UpdateProgress?.Invoke(this, e);
}
}
public interface IProcessor {
event EventHandler<UpdateProgressEventArgs> UpdateProgress;
}
public class UpdateProgressEventArgs {
public int Percentage { get; set; }
public string Caller { get; set; }
public DateTime UpdateDateTime { get; set; }
}
Just sending the progress from child to parent won't do the trick obviously. I hope someone can help me find a solution for this. Or if someone has another brilliant solution :)
Thanks in advance

Engine could maintain a private list of "the last completeness" of each process. In a Dictionary more than likely.
if we extend your Engine class to have this.
private Dictionary<IProcessor, int> _lastReportedPercentage = new Dictionary<IProcessor, int>();
and in the constructor where all your child processors are defined, set them all to 0.
public Engine()
{
//your other stuff
_lastReportedPercentage[_processorA] = 0;
_lastReportedPercentage[_processorB] = 0;
_lastReportedPercentage[_processorC] = 0;
_lastReportedPercentage[_processorD] = 0;
}
in your Event handler for the child processes do something like this:
private void ProcessorA_UpdateProgress(object sender, UpdateProgressEventArgs e)
{
_lastReportedPercentage[(IProcessor)sender] = e.Percentage;
var totalCompleteness = (int)Math.Floor(_lastReportedPercentage.Values.Sum() / _lastReportedPercentages.Values.Count);
OnUpdateProgress(new UpdateProgressEventArgs() { Caller = nameof(Engine), Percentage = totalCompleteness, UpdateDateTime = DateTime.Now });
}
You will then be reporting, from your Engine, the total completeness of all tasks.
There are some obvious design flaws to this, but you get the idea. It can be extended for a variable number of Processors if they're loaded from not-the-constructor, etc. but this should give you the desired output you'd want.

I would suggest having each processor keep a count of how many items it has completed, and how many items it has remaining.
This way the engine receives updates whenever an item is completed, as well as when an item is added to the processor.
As in Skintkingle's answer, you would then store the last received update from each processor within the engine.
You can then let the engine decide on the best way to put this information across. Something as simple as total completed / total remaining would work well.

Assigning event to subscribe with new

I'm making QuestSystem in unity.
what i want to do is assigning to my questData an event so it can know when the quest objective has been completed.
Lets say there is a class named A and action called a.
and i want Class B, Action b want to have reference to A.a
So if i do
b = A.a;,
b+= someAction;, it actually does a+=someAction;
but when if i do that. It will just simply b+=someAction and A.a will remain null
what should i do to perform what i want?
here are some tags. (i don't know what the answer would be. so..)
# event
# subscribing event
# assigning event
# referencing event
# action
# delegate
====== Edited =======
here is my code.
QuestData.cs
public class QuestData
{
public string questName;
public string qusetID;
public string questDescription;
public SceneType questSceneType;
private string isActivePrefsKey { get { return $"QuestKey{qusetID}"; } }
public bool isActive {
get {
return Convert.ToBoolean (PlayerPrefs.GetInt (isActivePrefsKey));
}
set { PlayerPrefs.SetInt (isActivePrefsKey, Convert.ToInt16 (value)); }
}
public QuestObjective questObjective;
public QuestReward questReward;
public void Activate ()
{
if (AppController.CurrentScene == questSceneType) {
questObjective.ActivateObjective ();
}
}
}
QuestObjective.cs
public class QuestObjective
{
// TODO rename all
public int goalObjectiveCount;
public int currentObjectiveCount;
public Action questAction;
public void OnConditionMatch ()
{
Debug.Log ("OnConditionMatch");
currentObjectiveCount += 1;
}
public void ActivateObjective ()
{
questAction += OnConditionMatch;
}
}
QuestManager.cs
public class QuestManager : MonoBehaviour
{
List<QuestData> questDatas;
void Awake ()
{
PrepareQuestDatas ();
ActivateActiveQuests ();
}
void ActivateActiveQuests ()
{
var activeQuests = GetActiveQuests ();
foreach (var activeQuest in activeQuests) {
activeQuest.Activate ();
}
}
List<QuestData> GetActiveQuests ()
{
// for debuging
return questDatas;
// real code
return questDatas.Where (q => q.isActive == true).ToList ();
}
public void PrepareQuestDatas ()
{
questDatas = new List<QuestData> {
new QuestData {
questName = "Foot Print",
questDescription = "win the game for first time",
questSceneType = SceneType.Main,
questObjective = new QuestObjective {
goalObjectiveCount = 1,
questAction = GamePlayController.instance.endGameCon.onWinGame
},
questReward = new QuestCoinReward{
rewardAmount = 100,
},
}
};
}
}

One potential solution is to create a new set of EventArgs, like this:
public class QuestCompletedEventArgs : System.EventArgs
{
public QuestObjective FinishedObjective { get; }
public QuestCompletedEventArgs(QuestObjective objectiveIn) {
this.FinishedObjective = objectiveIn;
}
}
(probably in a different file)
... and use it like this:
First, create an event delegate:
public delegate void QuestObjectiveCompleteHandler(object sender, QuestCompletedEventArgs e);
Instantiate the event delegate:
public event QuestObjectiveCompletedHandler CompletedObjective;
Define the method that will do something when the objective is completed:
public void ObjectiveCompleted(object sender, QuestCompletedEventArgs e)
{
// do something
}
Assign that method to the event:
this.CompletedObjective += this.ObjectiveCompleted;
From here, you can make the FinishedObjective object within the QuestCompletedEventArgs a List<QuestObjective>, and FinishedObjective.add(objectiveIn) whenever appropriate.
You should also be able to make the event handling method act differently when a certain amount of objectives have been completed, or whatever you want to do with that information.
Of course, you can also add multiple different methods to respond to this event by adding more this.CompletedObjective += this.methodName; lines, as long as the signature of the new method(s) carry that same signature.

Reading into your example, I have written up some code where "A" is QuestObjective and "B" is Quest. The Quest object needs to know when objective has been marked as completed.
Using event handlers, we can set it up so that B is notified when an action occurs on A.
Like this:
// B
public class Quest
{
public Quest()
{
Objectives = new List<QuestObjective>();
// load objectives... Fake
Objectives.Add(new QuestObjective("obj 1"));
Objectives.Add(new QuestObjective("obj 2"));
Objectives.Add(new QuestObjective("obj 3"));
foreach(var o in Objectives) // subscribe to QuestObjective events
{
o.ObjectiveCompleted += (sender, args) => ReportObjectiveCompleted();
}
}
public void ReportObjectiveCompleted()
{
// let 'em know
}
public List<QuestObjective> Objectives { get; set; }
}
// A
public class QuestObjective
{
public string Name { get; set; }
public QuestObjective(string name = "unknown")
{
Name = name;
}
public event EventHandler ObjectiveCompleted;
public void MarkCompleted()
{
// when a task is marked as complete and IF there are
// subscribers to this event then call the event handler
var a = ObjectiveCompleted;
if (a != null)
{
a(this, new EventArgs()); // use different event args to pass data
}
}
}

Conditional EventHandling

I believe I have a design question and I hope to get your input. I made a small program to illustrate my question. Basically, my program consists of a radio system that gets heard on every room in the building. The sound is conditional on the receiving end, depending if the room registers itself to the radio system.
My problem is that the message sent is triggered on every room, even if the room is not registered. I would prefer to do the condition before the message gets sent out, rather then on the receiving end. By doing this, I could save myself unnecessary traffic. Can anyone give me an idea or the correct way to resolve this type of situation?
Just for the record, I would prefer not to have multiple event handlers in the radio, since I don't know how many rooms there will be.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Radio
{
#region Speakers
public interface ISound
{
string sound { get; set; }
}
public abstract class RoomSpeaker : ISound
{
public string sound { get; set; }
}
public class Room1Speaker : RoomSpeaker
{
}
public class Room2Speaker : RoomSpeaker
{
}
public class BuildingSpeaker : RoomSpeaker
{
}
#endregion
#region Rooms
public abstract class Room
{
public Radio radioPlayer;
public string name;
public HashSet<Type> registeredSpeakers = new HashSet<Type>();
public virtual void RoomPlayer(string lyrics)
{
registeredSpeakers.Add(typeof(BuildingSpeaker));
Console.WriteLine(lyrics);
}
}
public class Room1 : Room
{
public Room1(Radio radioPlayer)
{
this.radioPlayer = radioPlayer;
name = "Room1";
registeredSpeakers.Add(typeof(Room1Speaker));
radioPlayer.onRadio += radioPlayer_onRadio;
}
// This is what I don't think I like. It will only do something if it's registered. That's fine.
// But on any radio message out, this room will get called regardless. Should I NOT be doing this? Should I go back to
// making an eventHandler for every room? rather then having one even handler for all the rooms and have a condition on the receiving end.
void radioPlayer_onRadio(object sender, ISound e)
{
if (registeredSpeakers.Contains(e.GetType()))
RoomPlayer(name + e.sound);
}
}
public class Room2 : Room
{
public Room2(Radio radioPlayer)
{
this.radioPlayer = radioPlayer;
name = "Room2";
registeredSpeakers.Add(typeof(Room2Speaker));
radioPlayer.onRadio += radioPlayer_onRadio;
}
void radioPlayer_onRadio(object sender, ISound e)
{
// same problem as in Room1.
if (registeredSpeakers.Contains(e.GetType()))
RoomPlayer(name + e.sound);
}
}
#endregion
public class Radio
{
public event EventHandler<ISound> onRadio;
public void PlayRoom1()
{
onRadio(this, new Room1Speaker() { sound = "Test" });
}
public void PlayRoom2()
{
onRadio(this, new Room2Speaker() { sound = "Test" });
}
public void PlayAllRooms()
{
onRadio(this, new BuildingSpeaker() { sound = "Test All Rooms" });
}
}
class Program
{
static void Main(string[] args)
{
var radio = new Radio();
var room1 = new Room1(radio);
var room2 = new Room2(radio);
radio.PlayRoom1();
radio.PlayRoom2();
radio.PlayAllRooms();
Console.ReadLine();
}
}
}

Okay, what you're looking at is the publish-subscribe pattern (AKA eventbus). In eventbus pattern, you have a class that registers listeners and sends messages. Listeners tell the event bus "I'm listening for an event X". When the eventbus "sends" event X it consults its list of listeners for that event and if they are registered, executes the method that the listener told it to execute.
public class EventBus
{
private Dictionary<Type, List<Action<IEvent>>> actions = new Dictionary<Type, List<Action<IEvent>>>();
public void Listen<T>(Action<IEvent> callback) where T : IEvent
{
if (!actions.ContainsKey(typeof(T)))
{
actions.Add(typeof(T), new List<Action<IEvent>>());
}
actions[typeof(T)].Add(callback);
}
public void ClearCallbacks<T>() where T : IEvent
{
actions[typeof (T)] = null;
}
public void Send<T>(T #event) where T : IEvent
{
if (!actions.ContainsKey(typeof(T)))
{
return;
}
foreach (var action in actions[typeof(T)])
{
action(#event);
}
}
}
public interface IEvent
{
}
Usage:
public static void main () {
var eventBus = new EventBus();
var aRoom = new NoisyRoom(eventBus);
var bRoom = new NoisyRoom(eventBus);
var cRoom = new NoisyRoom(eventBus);
var dRoom = new QuietRoom(eventBus);
eventBus.Send(new NoisyEvent()); //sends to a,b,c room
}
public class EasyListeningEvent : IEvent
{
}
public class QuietRoom
{
public QuietRoom(EventBus eventBus)
{
eventBus.Listen<EasyListeningEvent>(BringTheNaps);
}
private void BringTheNaps(IEvent #event)
{
//its been brought!
}
}
class NoisyEvent : IEvent
{
}
public class NoisyRoom
{
public NoisyRoom(EventBus eventBus)
{
eventBus.Listen<NoisyEvent>(BringTheNoise);
}
private void BringTheNoise(IEvent #event)
{
//its been brought!
}
}

Try something a little more like this:
Edit: Note that this is just a start in the right direction. You can take this a lot further. Basically what you have is a sound source and a sound emitter. Obviously a radio is a sound source, and a speaker is a sound emitter, but something like a room could be both. A radio should not know what a speaker or a room is, it should only know about emitters, and it should only send sounds to them. Based on this, a room should have a collection of emitters (which would probably be speakers), and when a room gets a sound from a radio, it would simply relay that to whatever emitters it has registered. There would also be nothing stopping you from registering speaker directly to a radio. This code should help show how you might implement all of that.
public class Radio
{
private HashTable<string, EventHandler<ISound>> rooms = new ...;
public void RegisterRoom(string room, EventHandler<ISound> onSound)
{
rooms[room] = onSound;
}
public void UnregisterRoom(string room)
{
rooms.Remove(room);
}
public void PlayRoom(string room)
{
EventHandler<ISound> onSound;
if (rooms.TryGetValue(room, out onSound))
{
onSound(this, new BuildingSpeaker() { sound = "Test" });
}
}
public void PlayAllRooms()
{
if (rooms.Count == 0)
{
return;
}
var speaker = new BuildingSpeaker() { sound = "Test All Rooms" };
foreach (var room in rooms)
{
room.Value(this, speaker);
}
}
}

Custom event and invocation on main thread

I was given a generic API class, that contains a custom event which always needs to be invoked by the main UI thread.
My job is to banish these invocation call from the custom class, to make it "painless".
It should be synchronized like the default events in WinForms (eg the Timer "Elapsed" event, which also needs no invocation when it published values to a text box)
Is it possible to solve this, since the custom class needs to know where to invoke?
Here's the (important part of the) code:
public class ContactSensorHelper
{
public event OnReleaseStateChanged ReleaseStateChanged;
public delegate void OnReleaseStateChanged(ContactSensorEventArgs e);
private ContactSensorEventArgs.ReleaseState recentReleaseState;
public void ReportStateChanged()
{
if (ReleaseStateChanged != null)
ReleaseStateChanged(new ContactSensorEventArgs()
{
State = recentReleaseState
});
}
public class ContactSensorEventArgs : EventArgs
{
//......
public ReleaseState State { get; set; }
//......
public enum ReleaseState
{
FullReleased,
PartlyReleased,
NotReleased
}
}
}
The call from main UI:
public void SensorInit()
{
//....
sensorHelper.ReleaseStateChanged += releaseStateChanged;
//....
}
private void releaseStateChanged(ContactSensorEventArgs e)
{
//example
textBox1.Text = e.State.ToString(); // Thread exception (obviously)
}
Does anybody have me a hint to start?

You could do this by using your own event calling, and storing a reference to the thread, when the event is attached.
With the event add/remove syntax, you can have the caller attach to the event like before, but internally you store a list, with a reference to the thread (using an AsyncOperation) and the delegate to be called (used a Tuple containing both in the example)
Below is an example. I tested it, and it worked as expected when testing, but you might have to add some locking of the list to make it thread safe in case events are added/removed simultaneously.
public class ContactSensorHelper:IDisposable
{
public delegate void OnReleaseStateChanged(ContactSensorEventArgs e);
private ContactSensorEventArgs.ReleaseState recentReleaseState;
public void ReportStateChanged()
{
if (statechangedList.Count > 0)
{
var e = new ContactSensorEventArgs()
{
State = recentReleaseState
};
statechangedList.ForEach(t =>
t.Item1.Post(o => t.Item2((ContactSensorEventArgs)o), e));
}
}
List<Tuple<AsyncOperation, OnReleaseStateChanged>> statechangedList = new List<Tuple<AsyncOperation,OnReleaseStateChanged>>();
public event OnReleaseStateChanged ReleaseStateChanged
{
add
{
var op = AsyncOperationManager.CreateOperation(null);
statechangedList.Add(Tuple.Create(op, value));
}
remove
{
var toremove = statechangedList.Where(t => t.Item2 == value).ToArray();
foreach (var t in toremove)
{
t.Item1.OperationCompleted();
statechangedList.Remove(t);
}
}
}
public void Dispose()
{
statechangedList.ForEach(t => t.Item1.OperationCompleted());
statechangedList.Clear();
}
public class ContactSensorEventArgs : EventArgs
{
//......
public ReleaseState State { get; set; }
//......
public enum ReleaseState
{
FullReleased,
PartlyReleased,
NotReleased
}
}
}