C# Func and Action delegate
Func and Action from System namespace
C# System
namespace defines several generic
delegates to convert almost all possible method signatures.
delegate TResult Func <out TResult> ();
delegate TResult Func <in T, out TResult> (T arg);
delegate TResult Func <in T1, in T2, out TResult> (T1 arg1, T2 arg2);
//from w w w . j a va2 s . c om
... and so on, up to T16
delegate void Action ();
delegate void Action <in T> (T arg);
delegate void Action <in T1, in T2> (T1 arg1, T2 arg2);
... and so on, up to T16
Example
We can rewrite the printer delegate as follows.
//www. j a va 2 s. c o m
using System;
class Test
{
static void output(int[] intArray, Action<int> p)
{
foreach (int i in intArray)
{
p(i);
}
}
static void consolePrinterInt(int i)
{
Console.WriteLine(i);
}
static void Main()
{
Action<int> p = consolePrinterInt;
int[] intArray = new int[] { 1, 2, 3 };
output(intArray, p);
}
}
The output: