PlaySound function

[zweistein]

Hi,


I see an example:

PlaySound(@":\Myfile.wav")


1. could you please explain what the @ means here?

2. Does the function also work without the @ ?

3. Is it possible to specify syncronous or asyncroneous playing?

4. Will PlaySound queue consecutive play requests even if a request comes in
while the previous sound is still playing?


Best regards

Andreas

[NinjaTrader_JoshP]

The @ forces it to a specific directory. If you do not use the @ it will go from the default directory mapping. I would just use the @ since it makes things simply to understand exactly where the file is located.

Not sure what you mean synchronous or asynchronous playing. It will play a sound when the function is called.

I believe it should. It may just play over the prior sound as the new call is reached. You could give it a try and see if it does what you want by calling PlaySound twice within a single OnBarUpdate().

[zweistein]

So ,

the NT PlaySound function is syncroneous. This means that calling PlaySound from within time critical code like OnMarketData will cause NT to be unresponsive (=hangs) for the time of the playing of the Sound file.

For who wants to go to an async version, here a code snippet to start with:

good luck

Andreas



----------------------------------------------

using System.IO;

public class Sound
{
private string m_fileName;

private enum Flags
{
SND_SYNC = 0x0000,
SND_ASYNC = 0x0001,
SND_NODEFAULT = 0x0002,
SND_LOOP = 0x0008,
SND_NOSTOP = 0x0010,
SND_NOWAIT = 0x00002000,
SND_FILENAME = 0x00020000,
SND_RESOURCE = 0x00040004

}

[System.Runtime.InteropServices.DllImport("winmm.DL L", EntryPoint = "PlaySound", SetLastError = true)]
private static extern bool PlaySound(string szSound, System.IntPtr hMod, Flags flags);


/// <summary>
/// Construct the Sound object to play sound data from the specified file.
/// </summary>
public void SoundInNTSoundsDir(string filename){
System.IO.DirectoryInfo directoryInfo=
System.IO.Directory.GetParent(System.IO.Directory. GetCurrentDirectory());
m_fileName=directoryInfo.ToString();
m_fileName+="\\sounds\\";
m_fileName+=filename;
}
public Sound(string fileName)
{
m_fileName = fileName;
}

/// <summary>
/// Play the sound
/// </summary>
public void Play()
{
// if a file name has been registered, call PlaySound,

if (m_fileName != null)
PlaySound(m_fileName, IntPtr.Zero, Flags.SND_ASYNC | Flags.SND_FILENAME);
}
}

main(){

Sound S;
S = new Sound("");
S.SoundInNTSoundsDir("Alert1.wav");
S.Play();

}

[eDanny]

I don't seem to have a problem with PlaySound besides the constant barrage of sound. I have 3 charts with two types of PlaySound triggers with two different sounds each. Sometimes they are all going at once with a possible six sounds. For some reason I don't notice any slowdown from that.

[eDanny]

I take that back. When the sound is a continous buzzing, the Dom freezes momentarily. I will have to check out your solution.

[drmartell]

I found this site helpful with this: http://www.pinvoke.net/default.aspx/...nd.html?diff=y

Shows simple .NET code toward the bottom too.