Sample code for Maker pHAT in .NET C#

MakerpHATDemoCode.cs

using System;
using System.Device.Gpio;
using System.Threading;
using System.Diagnostics;

//LED
int led1 = 17;
int led2 = 18;
int led3 = 27;
int led4 = 22;
int led5 = 25;
int led6 = 12;
int led7 = 13;
int led8 = 19;

//Button
int sw1 = 21;
int sw2 = 16;
int sw3 = 20;

int buzzer = 26;

int none = 0;
int decrease = 1;
int increase = 2;
int all_off = 9;
int all_on = 10;

using GpioController controller = new();
controller.OpenPin(led1, PinMode.Output);
controller.OpenPin(led2, PinMode.Output);
controller.OpenPin(led3, PinMode.Output);
controller.OpenPin(led4, PinMode.Output);
controller.OpenPin(led5, PinMode.Output);
controller.OpenPin(led6, PinMode.Output);
controller.OpenPin(led7, PinMode.Output);
controller.OpenPin(led8, PinMode.Output);
controller.OpenPin(sw1, PinMode.InputPullDown);
controller.OpenPin(sw2, PinMode.InputPullDown);
controller.OpenPin(sw3, PinMode.InputPullDown);
controller.OpenPin(buzzer, PinMode.Output);

Console.CancelKeyPress += new ConsoleCancelEventHandler(keyboardInterruptHandler);

void keyboardInterruptHandler(object sender, ConsoleCancelEventArgs args)
{
    LED(all_off);
    GpioOff(buzzer);
}

void GpioOn(int gpio)
{
    controller.Write(gpio, PinValue.High);
}

void GpioOff(int gpio)
{
    controller.Write(gpio, PinValue.Low);
}

void Beep(int times, int milliSecond)
{
    for (int i = 0; i < times; i++)
    {
        GpioOn(buzzer);
        Thread.Sleep(milliSecond);
        GpioOff(buzzer);
        Thread.Sleep(milliSecond);
    }
}

void LED(int ledNumber)
{
    if (ledNumber == 1)
    {
        GpioOn(led1);
    }
    else
    {
        GpioOff(led1);
    }

    if (ledNumber == 2)
    {
        GpioOn(led2);
    }
    else
    {
        GpioOff(led2);
    }

    if (ledNumber == 3)
    {
        GpioOn(led3);
    }
    else
    {
        GpioOff(led3);
    }

    if (ledNumber == 4)
    {
        GpioOn(led4);
    }
    else
    {
        GpioOff(led4);
    }

    if (ledNumber == 5)
    {
        GpioOn(led5);
    }
    else
    {
        GpioOff(led5);
    }

    if (ledNumber == 6)
    {
        GpioOn(led6);
    }
    else
    {
        GpioOff(led6);
    }

    if (ledNumber == 7)
    {
        GpioOn(led7);
    }
    else
    {
        GpioOff(led7);
    }

    if (ledNumber == 8)
    {
        GpioOn(led8);
    }
    else
    {
        GpioOff(led8);
    }

    if (ledNumber == all_off)
    {
        GpioOff(led1);
        GpioOff(led2);
        GpioOff(led3);
        GpioOff(led4);
        GpioOff(led5);
        GpioOff(led6);
        GpioOff(led7);
        GpioOff(led8);
    }
    else if (ledNumber == all_on)
    {
        GpioOn(led1);
        GpioOn(led2);
        GpioOn(led3);
        GpioOn(led4);
        GpioOn(led5);
        GpioOn(led6);
        GpioOn(led7);
        GpioOn(led8);
    }
}

int mode = none;
int ledPosition = 0;

LED(all_on);
Beep(1, 100);
LED(all_off);

while (true)
{
    if (controller.Read(sw1) == PinValue.Low && mode != decrease)
    {
        Beep(2, 70);
        mode = decrease;
    }
    else if (controller.Read(sw2) == PinValue.Low && controller.Read(sw3) == PinValue.Low)
    {
        Thread.Sleep(500);
        for (int i = 0; i < 3; i++)
        {
            LED(all_on);
            GpioOn(buzzer);
            Thread.Sleep(200);
            LED(all_off);
            GpioOff(buzzer);
            Thread.Sleep(200);
        }
        Thread.Sleep(1000);

        Process.Start("/bin/bash", "-c \"sudo shutdown -h now\"");
    }
    else if (controller.Read(sw2) == PinValue.Low && mode != increase)
    {
        Beep(2, 70);
        mode = increase;
    }
    else if (controller.Read(sw3) == PinValue.Low && mode != none)
    {
        Beep(1, 70);
        mode = none;
    }

    if (mode == increase)
    {
        if (ledPosition < 8)
        {
            ledPosition = ledPosition + 1;
        }
        else 
        {
            ledPosition = 0;
        }
    }
    else if (mode == decrease)
    {
        if (ledPosition > 0)
        {
            ledPosition = ledPosition - 1;
        }
        else 
        {
            ledPosition = 8;
        }
    }

    LED(ledPosition);

    Thread.Sleep(50);
}

Please visit Maker pHAT Sample Code in .NET C# for some explainations.