C# defines and uses custom events in a program and can be divided into the following steps:
Step 1: Define events in class
using System;
public class TestClass
{
//....
public event EventHandler TestEvent
}
Step 2: Define event parameters
Note: The event parameter class TestEventArgs inherits from
using System;
public class TestEventArgs : EventArgs
{
public TestEventArgs() : base() { }
public string Message { get; set; }
}
Step 3: Raise an event in TestClass
public class TestClass
{
// This method causes an event
public void RaiseTestEvent(string message)
{
if (TestEvent == null) return;
TestEvent(this, new TestEventArgs { Message = message });
}
public event EventHandler TestEvent;
}
Step 4: Use events
class Program
{
static void Main(string[] args)
{
TestClass tc = new TestClass();
// How to handle hook event
+= Tc_TestEvent;
("Press any key to raise an event");
();
// Raise an event
("String passed through event parameters");
("Press any key to exit");
();
}
private static void Tc_TestEvent(object sender, EventArgs e)
{
// Cast event parameters to TestEventArgs
TestEventArgs te = (TestEventArgs)e;
// Display Message in event parameters
();
}
}
The complete procedure is as follows
using System;
public class TestClass
{
public void RaiseTestEvent(string message)
{
if (TestEvent == null) return;
TestEvent(this, new TestEventArgs { Message = message });
}
public event EventHandler TestEvent;
}
public class TestEventArgs : EventArgs
{
public TestEventArgs() : base() { }
public string Message { get; set; }
}
class Program
{
static void Main(string[] args)
{
TestClass tc = new TestClass();
+= Tc_TestEvent;
("Press any key to raise an event");
();
("String passed through event parameters");
("Press any key to exit");
();
}
private static void Tc_TestEvent(object sender, EventArgs e)
{
TestEventArgs te = (TestEventArgs)e;
();
}
}