Custom control event

Question

Hi,
I have a class called LISTENER, in this class i have 2 properties called Subject, Name and 1 event
public event MessageReceivedEventHandler ListenerMessageReceivedEvent;

Now i am creating a custom control and in that control i am adding a property called LISTENERS this property contains collection of LISTENER class.

Now i am placing this control in windows form and adding LISTENERs object properties. I am able to add N number of LISTENER object. But i am not able to bring the event "ListenerMessageReceivedEvent".

Can anyone help me on this?

Thanks in Advance.
Pals.

PALANISELVAM M · Answer

Hi Mike, Thanks a lot for your input. I am also doing similar way only. But it is not working. Actually my requirement is in the custom control one of the properties is collection of class which contain an event. Even i added [Browsable=true] attribute also. Though it is not working. I would like to know whether it is possible(A custom control property contains collection of objects, that object class contains an event, for each and every object i need to write an event). I have seen the solution in the following link. But it is not working for me. http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=438792&SiteID=1 Thanks and Regards, M. Palani Selvam.

Mike Gold · Answer

In order to bring up an event, some piece of code needs to fire it somewhere by calling a method. Check out Microsoft's MSDN example below for an alarm event: (Note in bold where the event is being fired by the control by calling the delegate Alarm(this, e); ) // EventSample.cs. // namespace EventSample { using System; using System.ComponentModel; // Class that contains the data for // the alarm event. Derives from System.EventArgs. // public class AlarmEventArgs : EventArgs { private readonly bool snoozePressed ; private readonly int nrings; //Constructor. // public AlarmEventArgs(bool snoozePressed, int nrings) { this.snoozePressed = snoozePressed; this.nrings = nrings; } // The NumRings property returns the number of rings // that the alarm clock has sounded when the alarm event // is generated. // public int NumRings { get { return nrings;} } // The SnoozePressed property indicates whether the snooze // button is pressed on the alarm when the alarm event is generated. // public bool SnoozePressed { get {return snoozePressed;} } // The AlarmText property that contains the wake-up message. // public string AlarmText { get { if (snoozePressed) { return ("Wake Up!!! Snooze time is over."); } else { return ("Wake Up!"); } } } } // Delegate declaration. // public delegate void AlarmEventHandler(object sender, AlarmEventArgs e); // The Alarm class that raises the alarm event. // public class AlarmClock { private bool snoozePressed = false; private int nrings = 0; private bool stop = false; // The Stop property indicates whether the // alarm should be turned off. // public bool Stop { get {return stop;} set {stop = value;} } // The SnoozePressed property indicates whether the snooze // button is pressed on the alarm when the alarm event is generated. // public bool SnoozePressed { get {return snoozePressed;} set {snoozePressed = value;} } // The event member that is of type AlarmEventHandler. // public event AlarmEventHandler Alarm; // The protected OnAlarm method raises the event by invoking // the delegates. The sender is always this, the current instance // of the class. // protected virtual void OnAlarm(AlarmEventArgs e) { if (Alarm != null) { // Invokes the delegates. Alarm(this, e); } } // This alarm clock does not have // a user interface. // To simulate the alarm mechanism it has a loop // that raises the alarm event at every iteration // with a time delay of 300 milliseconds, // if snooze is not pressed. If snooze is pressed, // the time delay is 1000 milliseconds. // public void Start() { for (;;) { nrings++; if (stop) { break; } else if (snoozePressed) { System.Threading.Thread.Sleep(1000); { AlarmEventArgs e = new AlarmEventArgs(snoozePressed, nrings); OnAlarm(e); } } else { System.Threading.Thread.Sleep(300); AlarmEventArgs e = new AlarmEventArgs(snoozePressed, nrings); OnAlarm(e); } } } } // The WakeMeUp class has a method AlarmRang that handles the // alarm event. // public class WakeMeUp { public void AlarmRang(object sender, AlarmEventArgs e) { Console.WriteLine(e.AlarmText +"
"); if (!(e.SnoozePressed)) { if (e.NumRings % 10 == 0) { Console.WriteLine(" Let alarm ring? Enter Y"); Console.WriteLine(" Press Snooze? Enter N"); Console.WriteLine(" Stop Alarm? Enter Q"); String input = Console.ReadLine(); if (input.Equals("Y") ||input.Equals("y")) return; else if (input.Equals("N") || input.Equals("n")) { ((AlarmClock)sender).SnoozePressed = true; return; } else { ((AlarmClock)sender).Stop = true; return; } } } else { Console.WriteLine(" Let alarm ring? Enter Y"); Console.WriteLine(" Stop Alarm? Enter Q"); String input = Console.ReadLine(); if (input.Equals("Y") || input.Equals("y")) return; else { ((AlarmClock)sender).Stop = true; return; } } } } // The driver class that hooks up the event handling method of // WakeMeUp to the alarm event of an Alarm object using a delegate. // In a forms-based application, the driver class is the // form. // public class AlarmDriver { public static void Main (string[] args) { // Instantiates the event receiver. WakeMeUp w= new WakeMeUp(); // Instantiates the event source. AlarmClock clock = new AlarmClock(); // Wires the AlarmRang method to the Alarm event. clock.Alarm += new AlarmEventHandler(w.AlarmRang); clock.Start(); } } }