C# overloads the + and - operators for delegate.
By using + and - we can add methods to or subtract methods from a delegate type variable.
delegateVariable += aMethod;
can be rewritten as
delegateVariable = delegateVariable + aMethod;
using System;
delegate void Printer(int i);
class Test
{
static void consolePrinter(int i)
{
Console.WriteLine(i);
}
static void consolePrinter2(int i)
{
Console.WriteLine("second:" + i);
}
static void Main()
{
Printer p = consolePrinter;
p += consolePrinter2;
p(1);
}
}
The output:
1
second:1
The delegates are called in the sequence of adding.
We can subtract delegate method as well.
using System;
delegate void Printer(int i);
class Test
{
static void consolePrinter(int i)
{
Console.WriteLine(i);
}
static void consolePrinter2(int i)
{
Console.WriteLine("second:" + i);
}
static void Main()
{
Printer p = consolePrinter;
p += consolePrinter2;
p -= consolePrinter;
p(1);
}
}
The output:
second:1