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Using Named Pipes in C#

i've been trying to use Named Pipes in C# for a while but can't get it to work.
I'm working with the following code:
internal class SplitManager
{
public static void initialize()
{
Debug.Log("Initializing LiveSplit pipe");
SplitManager.pipeClientStream = new NamedPipeClientStream("//.//pipe//LiveSplit");
Debug.Log("Successfully initialized LiveSplit pipe");
}
public static void startRun()
{
Debug.Log("[PIPE]: start");
SplitManager.WriteString("start");
}
public static void performSplit()
{
Debug.Log("[PIPE]: split");
SplitManager.WriteString("split");
}
private static void WriteString(string str)
{
SplitManager.pipeClientStream.Connect();
new StreamString(SplitManager.pipeClientStream).WriteString(str);
SplitManager.pipeClientStream.Close();
}
private static NamedPipeClientStream pipeClientStream;
}
public class StreamString
{
public StreamString(Stream ioStream)
{
this.ioStream = ioStream;
this.streamEncoding = new UnicodeEncoding();
}
public string ReadString()
{
int num = this.ioStream.ReadByte() * 256;
num += this.ioStream.ReadByte();
byte[] array = new byte[num];
this.ioStream.Read(array, 0, num);
return this.streamEncoding.GetString(array);
}
public int WriteString(string outString)
{
byte[] bytes = this.streamEncoding.GetBytes(outString);
int num = bytes.Length;
if (num > 65535)
{
num = 65535;
}
this.ioStream.WriteByte((byte)(num / 256));
this.ioStream.WriteByte((byte)(num & 255));
this.ioStream.Write(bytes, 0, num);
this.ioStream.Flush();
return bytes.Length + 2;
}
private Stream ioStream;
private UnicodeEncoding streamEncoding;
}
When i run this code i get Win32Exception with an error message that it cannot find the specified file. I'm 100% sure the path is fine, since i checked it with powershell command [System.IO.Directory]::GetFiles("\\.\\pipe\\"). Any ideas why does this error happen?

It turns out that C# actually provides the "//.//pipe//" prefix to the string, so simply replacing SplitManager.pipeClientStream = new NamedPipeClientStream("//.//pipe//LiveSplit"); to SplitManager.pipeClientStream = new NamedPipeClientStream("LiveSplit"); worked!

Paint event doesn't invoked

Trying to implement a random walk by moving the ball across the screen. Algorithm is looks like working but debug shows that the paint event doesn't invoked.
First of all, try to do this in pattern MVC. For clarity, I will give the code of these components.
View:
public partial class ViewBallBounce : Form, Observer
{
private ModelRandomWalk modelRandomWalk;
private ControllerRandomWalk controllerRandomWalk;
static int i = 0;
public ViewBallBounce(ModelRandomWalk _modelRandomWalk)
{
InitializeComponent();
this.modelRandomWalk = _modelRandomWalk;
controllerRandomWalk = new ControllerRandomWalk(modelRandomWalk, this, ClientSize.Width, ClientSize.Height);
modelRandomWalk.Register(this);
this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.DoubleBuffer, true);
this.UpdateStyles();
}
public void UpdateState()
{
this.Refresh();
}
private void ViewBallBounce_Load(object sender, EventArgs e)
{
controllerRandomWalk.Bounce();
}
private void ViewBallBounce_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
g.Clear(BackColor);
i++;
g.FillEllipse(Brushes.Blue, modelRandomWalk.X, modelRandomWalk.Y,
modelRandomWalk.Width, modelRandomWalk.Height);
g.DrawEllipse(Pens.Black, modelRandomWalk.X, modelRandomWalk.Y,
modelRandomWalk.Width, modelRandomWalk.Height);
}
}
Control:
public class ControllerRandomWalk
{
private ModelRandomWalk modelRandomWalk;
private ViewBallBounce viewBallBounce;
public int clientH, clientW;
public ControllerRandomWalk(ModelRandomWalk modelRandomWalk, ViewBallBounce viewBallBounce, int _width, int _height)
{
this.modelRandomWalk = modelRandomWalk;
this.viewBallBounce = viewBallBounce;
this.clientH = _height;
this.clientW = _width;
}
public int Bounce()
{
return modelRandomWalk.bounce(100, clientH, clientW);
}
}
Model:
public class ModelRandomWalk
{
private int x, y;
private int velocityX, velocityY;
private int width, height;
public int X { get { return x; } }
public int Y { get { return y; } }
public int VelocityX { get { return velocityX; } }
public int VelocityY { get { return velocityY; } }
public int Width { get { return width; } }
public int Height { get { return height; } }
public void updatePosition(int key)
{
if (key == 0) this.x += velocityX;
else this.y += velocityY;
}
public void updateVelocity(int key)
{
if (key == 0) this.velocityX = -this.velocityX;
else this.velocityY = -this.velocityY;
}
public ModelRandomWalk(int _x, int _y, int _width, int _height)
{
this.x = _x;
this.y = _y;
this.width = _width;
this.height = _height;
}
public int bounce(int _steps, int _h, int _w)
{
int steps = _steps;
int clientH = _h, clientW = _w;
for(int i = 0; i < steps; i++)
{
Random rnd = new Random();
int v = rnd.Next(0, 4); // 0 = +v_x, 1 = +v_y, 2 = -v_x, 3 = -v_y
switch (v)
{
case 0:
velocityX++;
break;
case 1:
velocityY++;
break;
case 2:
velocityX--;
break;
case 3:
velocityY--;
break;
}
updatePosition(0);
if (X < 0)
{
x = 6;
updateVelocity(0);
}
else if (X + Width > clientW)
{
x = clientW - 6;
updateVelocity(0);
}
updatePosition(1);
if (Y < 0)
{
y = 6;
updateVelocity(1);
}
else if (Y + Height > clientH)
{
y = clientH - 6;
updateVelocity(1);
}
UpdateObservers();
}
return 0;
}
private ArrayList listeners = new ArrayList();
public void Register(Observer o)
{
listeners.Add(o);
o.UpdateState();
}
public void Deregister(Observer o)
{
listeners.Remove(0);
}
public void UpdateObservers()
{
foreach (Observer el in listeners)
{
el.UpdateState();
}
}
}
Sorry for long post. The main problem in these lines, when ViewBallBounce_Paint doesn't invoke.
public void UpdateState()
{
this.Refresh();
}
private void ViewBallBounce_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
g.Clear(BackColor);
i++; //just checking has it invoked
g.FillEllipse(Brushes.Blue, modelRandomWalk.X, modelRandomWalk.Y,
modelRandomWalk.Width, modelRandomWalk.Height);
g.DrawEllipse(Pens.Black, modelRandomWalk.X, modelRandomWalk.Y,
modelRandomWalk.Width, modelRandomWalk.Height);
}
I have tried a lot of ways to set breakpoints and don't understand why after Refresh nothing happens. By the way, breakpoint in ViewBallBounce_Paint shows very strange modelRandomWalk.X or modelRandomWalk.Y as 224 or -78 and they don't change.
What's could be wrong?
UPD: New form is openned and the ball is drawen but it doesn't move. Changed steps in cycle to 10 and find out ball had moved only after ending the cycle in Model Component. Nevertheless, this.Refresh has worked but the paint event has invoked after 10 iterations. By the way, the movement occurred taking into account the changes in speeds and positions in the Model component. Wrote Thread.Sleep(1000) in ViewBallBounce_Paint but there were no changes.

Crash on Chrome when writing file on Webgl

In Unity3d Webgl I download and write big file (about 100 mb and more) to cache (indexeddb).
I downloaded file with UnityWebRequest and write file in downloadHandler.
Sometimes after call filestream.Write() or filestream.Flush() Chrome will crash.
Exception not available, only crash tab of chrome.
Crash happens abount in 50 percent of dowloads.
public class Downloader : MonoBehaviour
{
public IEnumerator DownloadFileCoroutine(string url, string filePath, string clientName, int fileId, Action<int> downloadedCallback)
{
var currentWebRequest = UnityWebRequest.Get(url);
currentWebRequest.downloadHandler = new ToFileDownloadHandler(new byte[64 * 1024], filePath);
var downloadHendler = (currentWebRequest.downloadHandler as ToFileDownloadHandler);
currentWebRequest.Send();
while (!currentWebRequest.isDone && !currentWebRequest.isNetworkError && !currentWebRequest.isHttpError)
{
if (currentWebRequest.isNetworkError)
{
yield break;
}
}
if (currentWebRequest.isNetworkError)
{
downloadHendler.Cancel();
}
else
{
/// suceess
}
}
public class ToFileDownloadHandler : DownloadHandlerScript
{
private int _expected = -1;
private long _received = 0;
private readonly string _filepath;
private readonly FileStream _fileStream = null;
private bool _canceled = false;
public ToFileDownloadHandler(byte[] buffer, string filepath) : base(buffer)
{
CreateDir();
_filepath = filepath;
_fileStream = new FileStream(filepath, FileMode.Create, FileAccess.Write);
}
protected override byte[] GetData() { return null; }
protected override bool ReceiveData(byte[] data, int dataLength)
{
if (data == null || data.Length < 1)
{
return false;
}
_received += dataLength;
if (!_canceled)
{
_fileStream.Write(data, 0, dataLength);
_fileStream.Flush();
}
return true;
}
protected override float GetProgress()
{
if (_expected < 0) return 0;
return (float)_received / _expected;
}
protected override void CompleteContent()
{
_fileStream.Close();
_isComplete = true;
}
protected override void ReceiveContentLength(int contentLength)
{
_expected = contentLength;
}
public void Cancel()
{
if (_canceled) return;
_canceled = true;
if (_fileStream != null)
{
_fileStream.Close();
}
File.Delete(_filepath);
}
private void CreateDir()
{
cachePath = Application.persistentDataPath;
if (!Directory.Exists(cachePath))
{
Directory.CreateDirectory(cachePath);
}
}
}
}

Xamarin Binding Libriary 'Overlay': member names cannot be the same as their enclosing type

I'm need rename field "Overlay", but not remove.
I'm try make link native jar lib to xamarin dll.
I`m create new Binding Libriary project and include jar file inside.
But when i'm try build solution, system output window get error
'Overlay': member names cannot be the same as their enclosing type.
I'm try configurate MetaData file in the following way.
<metadata>
<remove-node path="/api/package[#name='Com.Cdcom.Naviapps.Progorod']/class[#name='Overlay']/method[#name='Overlay']" />
</metadata>
or
<remove-node path="/api/package[#name='Com.Cdcom.Naviapps.Progorod']/class[#name='Overlay']" />
or i'm try change EnumMethods
<enum-method-mappings>
<mapping jni-class="/api/package[#name='com.cdcom.naviapps.progorod']/class[#name='Overlay']">
<method jni-name="Overlay" parameter="return" clr-enum-type="Android.OS.Overlay" />
</mapping>
</enum-method-mappings>
but i'm get other error
"generator.exe" exited with code -532462766.
You can see the class from first error below
// Metadata.xml XPath class reference: path="/api/package[#name='com.cdcom.naviapps.progorod']/class[#name='Overlay']"
[global::Android.Runtime.Register ("com/cdcom/naviapps/progorod/Overlay", DoNotGenerateAcw=true)]
public partial class Overlay : global::Java.Lang.Object {
//region "Event implementation for Com.Cdcom.Naviapps.Progorod.Overlay.IOnOverlayListener"
public event EventHandler<global::Com.Cdcom.Naviapps.Progorod.Overlay.OverlayEventArgs> Overlay {
add {
global::Java.Interop.EventHelper.AddEventHandler<global::Com.Cdcom.Naviapps.Progorod.Overlay.IOnOverlayListener, global::Com.Cdcom.Naviapps.Progorod.Overlay.IOnOverlayListenerImplementor>(
ref weak_implementor___SetOnOverlayListener,
__CreateIOnOverlayListenerImplementor,
__v => OnOverlayListener = __v,
__h => __h.Handler += value);
}
remove {
global::Java.Interop.EventHelper.RemoveEventHandler<global::Com.Cdcom.Naviapps.Progorod.Overlay.IOnOverlayListener, global::Com.Cdcom.Naviapps.Progorod.Overlay.IOnOverlayListenerImplementor>(
ref weak_implementor___SetOnOverlayListener,
global::Com.Cdcom.Naviapps.Progorod.Overlay.IOnOverlayListenerImplementor.__IsEmpty,
__v => OnOverlayListener = null,
__h => __h.Handler -= value);
}
}
//endregion
}
Original java code
public class Overlay
{
public List<OverlayItem> getItems()
{
return this.mOverlayItems;
}
public OnOverlayListener getOnOverlayListener()
{
return this.mOverlayListener;
}
public void populate()
{
double[] latlon = new double[this.mOverlayItems.size() * 2];
int d = 0;
for (OverlayItem oi : this.mOverlayItems)
{
latlon[(d++)] = oi.getGeoPoint().getLatitude();
latlon[(d++)] = oi.getGeoPoint().getLongitude();
}
Native.populateOverlay(this.mId, latlon);
}
public void setBitmap(Bitmap bitmap, float xOffset, float yOffset, boolean isPlain, int sizeInMeters)
{
int width = 0;
int height = 0;
int[] pixels = null;
if (bitmap != null)
{
width = bitmap.getWidth();
height = bitmap.getHeight();
pixels = new int[width * height];
bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
}
Native.setOverlayBitmap(this.mId, width, height, pixels, xOffset, yOffset, isPlain, sizeInMeters);
}
public void setOnOverlayListener(OnOverlayListener listener)
{
this.mOverlayListener = listener;
}
public static int SPECIAL_OVERLAY_START_ROUTE = -1;
public static int SPECIAL_OVERLAY_FINISH_ROUTE = -2;
public static int SPECIAL_OVERLAY_ROUTE_SPRITE = -3;
public static int SPECIAL_OVERLAY_GEOBLOG_SPRITE = -4;
private static int SPECIAL_OVERLAYS_COUNT = 4;
public static Overlay specialOverlay(int id)
{
if (mSpecialOverlays[(id + SPECIAL_OVERLAYS_COUNT)] == null)
{
mSpecialOverlays[(id + SPECIAL_OVERLAYS_COUNT)] = new Overlay();
mSpecialOverlays[(id + SPECIAL_OVERLAYS_COUNT)].mId = id;
}
return mSpecialOverlays[(id + SPECIAL_OVERLAYS_COUNT)];
}
protected int getId()
{
return this.mId;
}
protected int mId = mNextId++;
private static int mNextId = 1;
private List<OverlayItem> mOverlayItems = new ArrayList();
private OnOverlayListener mOverlayListener;
private static Overlay[] mSpecialOverlays = new Overlay[SPECIAL_OVERLAYS_COUNT];
public static abstract interface OnOverlayListener
{
public abstract void onOverlayEvent(Overlay paramOverlay, OverlayItem paramOverlayItem);
}
}

Beep in C# .NET application on server side

To debug a firewall delay issue I need an application that will produce a beep on server side when it detects an HTTP GET request.
This code (test.ashx):
<%# WebHandler Language="C#" Class="TestHandler" %>
using System;
using System.Web;
public class TestHandler : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
HttpResponse Response = context.Response;
try
{
Response.Write("Before beep");
Console.Beep();
Response.Write("After beep");
}
catch (Exception ex)
{
Response.Write(ex.Message + "<br />\n" + ex.InnerException.Message);
}
}
public bool IsReusable { get { return false; } }
}
produces sound only when debugging in IIS Express. After moving the web app to IIS, the sound disappears.

The three easy ways of producing a sound are System.Console.Beep(), System.Media.SoundPlayer, and System.Media.SystemSounds.Beep().
Unfortunately, these methods only work in desktop applications, and won't work in service applications. When ASP.Net apps are run under IIS Express (a desktop app), these sound methods work. However, when ASP.Net apps are run under the IIS service, the sound methods don't work.
System.Console.Beep() ultimately calls the kernel32.dll Beep() function. It's restricted to desktop apps only (scroll down to the Requirements section).
Same for System.Media.SoundPlayer and System.Media.SystemSounds.Beep(). They call the kernel32.dll MessageBeep() and the winmm.dll PlaySound() functions, respectively. They, too, are restricted to desktop apps.
One way to get sounds to play in a service is use NAudio. It's easy to install via NuGet.
This chunk of code is the only way I could get the sound to play. It has to be played on a separate worker thread, and the execution of the worker thread needs to be paused to let the .wav file finish playing.
using System;
using System.Diagnostics;
using System.Threading;
using NAudio.Dsp;
using NAudio.Wave;
...
protected void Button1_Click(object sender, EventArgs e)
{
var waveFilename = #"c:\Windows\Media\tada.wav";
/* Trying to play the .wav file on the main thread
doesn't seem to work. */
ThreadPool.QueueUserWorkItem(
(state) =>
{
using (var audioPlayback = new AudioPlayback())
{
audioPlayback.Load(waveFilename);
audioPlayback.Play(); // Asynchronous.
/* Need to sleep for the approximate length of .wav file,
otherwise no sound is produced because of the
asynchronous Play() call. */
Thread.Sleep(2000);
}
});
}
Here's the supporting code taken from code in NAudio's NAudioWPFDemo project:
public class MaxSampleEventArgs : EventArgs
{
[DebuggerStepThrough]
public MaxSampleEventArgs(float minValue, float maxValue)
{
this.MaxSample = maxValue;
this.MinSample = minValue;
}
public float MaxSample { get; private set; }
public float MinSample { get; private set; }
}
public class FftEventArgs : EventArgs
{
[DebuggerStepThrough]
public FftEventArgs(Complex[] result)
{
this.Result = result;
}
public Complex[] Result { get; private set; }
}
public class SampleAggregator : ISampleProvider
{
// volume
public event EventHandler<MaxSampleEventArgs> MaximumCalculated;
private float maxValue;
private float minValue;
public int NotificationCount { get; set; }
int count;
// FFT
public event EventHandler<FftEventArgs> FftCalculated;
public bool PerformFFT { get; set; }
private readonly Complex[] fftBuffer;
private readonly FftEventArgs fftArgs;
private int fftPos;
private readonly int fftLength;
private int m;
private readonly ISampleProvider source;
private readonly int channels;
public SampleAggregator(ISampleProvider source, int fftLength = 1024)
{
channels = source.WaveFormat.Channels;
if (!IsPowerOfTwo(fftLength))
throw new ArgumentException("FFT Length must be a power of two");
this.m = (int) Math.Log(fftLength, 2.0);
this.fftLength = fftLength;
this.fftBuffer = new Complex[fftLength];
this.fftArgs = new FftEventArgs(fftBuffer);
this.source = source;
}
private bool IsPowerOfTwo(int x)
{
return (x & (x - 1)) == 0;
}
public void Reset()
{
count = 0;
maxValue = minValue = 0;
}
private void Add(float value)
{
if (PerformFFT && FftCalculated != null)
{
fftBuffer[fftPos].X = (float) (value * FastFourierTransform.HammingWindow(fftPos, fftLength));
fftBuffer[fftPos].Y = 0;
fftPos++;
if (fftPos >= fftBuffer.Length)
{
fftPos = 0;
// 1024 = 2^10
FastFourierTransform.FFT(true, m, fftBuffer);
FftCalculated(this, fftArgs);
}
}
maxValue = Math.Max(maxValue, value);
minValue = Math.Min(minValue, value);
count++;
if (count >= NotificationCount && NotificationCount > 0)
{
if (MaximumCalculated != null)
MaximumCalculated(this, new MaxSampleEventArgs(minValue, maxValue));
Reset();
}
}
public WaveFormat WaveFormat { get { return source.WaveFormat; } }
public int Read(float[] buffer, int offset, int count)
{
var samplesRead = source.Read(buffer, offset, count);
for (int n = 0; n < samplesRead; n += channels)
Add(buffer[n + offset]);
return samplesRead;
}
}
public class AudioPlayback : IDisposable
{
private IWavePlayer _playbackDevice;
private WaveStream _fileStream;
public void Load(string fileName)
{
Stop();
CloseFile();
EnsureDeviceCreated();
OpenFile(fileName);
}
private void CloseFile()
{
if (_fileStream != null)
{
_fileStream.Dispose();
_fileStream = null;
}
}
private void OpenFile(string fileName)
{
try
{
var inputStream = new AudioFileReader(fileName);
_fileStream = inputStream;
var aggregator = new SampleAggregator(inputStream);
aggregator.NotificationCount = inputStream.WaveFormat.SampleRate / 100;
aggregator.PerformFFT = true;
_playbackDevice.Init(aggregator);
}
catch
{
CloseFile();
throw;
}
}
private void EnsureDeviceCreated()
{
if (_playbackDevice == null)
CreateDevice();
}
private void CreateDevice()
{
_playbackDevice = new WaveOut { DesiredLatency = 200 };
}
public void Play()
{
if (_playbackDevice != null && _fileStream != null && _playbackDevice.PlaybackState != PlaybackState.Playing)
_playbackDevice.Play();
}
public void Pause()
{
if (_playbackDevice != null)
_playbackDevice.Pause();
}
public void Stop()
{
if (_playbackDevice != null)
_playbackDevice.Stop();
if (_fileStream != null)
_fileStream.Position = 0;
}
public void Dispose()
{
Stop();
CloseFile();
if (_playbackDevice != null)
_playbackDevice.Dispose();
}
}

Try this System.Media.SystemSounds.Beep.Play();