/// <summary>
/// Empties header queue.
/// </summary>
private void EmptyHeaderQueue()
{
IEnumerator en = syncHeaderQueue.GetEnumerator();
// While there are still headers in the queue.
while (en.MoveNext())
{
// Get header.
MidiHeader header = (MidiHeader)en.Current;
// Unprepare header.
ThrowOnError(midiOutUnprepareHeader(handle, ref header,
Marshal.SizeOf(header)));
// Free memory allocated for the system exclusive data.
Marshal.FreeHGlobal(header.data);
}
// Clear queue.
syncHeaderQueue.Clear();
}
/// <summary>
/// Handles triggering the system exclusive message received event.
/// </summary>
/// <param name="header">
/// Midi header containing the system exclusive message.
/// </param>
/// <param name="timeStamp">
/// Number of milliseconds that have passed since the input device
/// began recording.
/// </param>
private void DispatchSysExMessage(MidiHeader header, int timeStamp)
{
// Create array for holding system exclusive data.
byte[] data = new byte[header.bytesRecorded - 1];
// Get status byte.
byte status = Marshal.ReadByte(header.data);
// Copy system exclusive data into array (status byte is
// excluded).
for (int i = 1; i < header.bytesRecorded; i++)
{
data[i - 1] = Marshal.ReadByte(header.data, i);
}
// Create message.
SysExMessage msg = new SysExMessage((SysExType)status, data);
// Raise event.
SysExReceived(this, new SysExEventArgs(msg, timeStamp));
}
/// <summary>
/// Manages system exclusive messages received by the input device.
/// </summary>
/// <param name="param1">
/// Integer pointer to the header containing the received system
/// exclusive message.
/// </param>
/// <param name="timeStamp">
/// Number of milliseconds that have passed since the input device
/// began recording.
/// </param>
private void ManageSysExMessage(int param1, int timeStamp)
{
// Get pointer to header.
IntPtr ptrHeader = new IntPtr(param1);
// If anyone is listening for system exclusive messages.
if (SysExReceived != null)
{
// Imprint raw pointer on to structure.
MidiHeader header = (MidiHeader)Marshal.PtrToStructure(ptrHeader, typeof(MidiHeader));
// Dispatches system exclusive messages.
DispatchSysExMessage(header, timeStamp);
}
// Enqueue next system exclusive header and signal the worker queue
// that another header is ready to be processed.
lock (lockObject)
{
sysExHeaderQueue.Enqueue(ptrHeader);
Monitor.Pulse(lockObject);
}
}
/// <summary>
/// Thread method for managing headers.
/// </summary>
private void ManageHeaders()
{
// While the device is open.
while (IsOpen())
{
// Wait to be signalled when a header had finished being used.
resetEvent.WaitOne();
// While there are still headers in the queue.
while (syncHeaderQueue.Count > 0)
{
// Get header from the front of the queue.
MidiHeader header = (MidiHeader)syncHeaderQueue.Dequeue();
// Unprepare header.
int result = midiOutUnprepareHeader(handle, ref header,
Marshal.SizeOf(header));
// If an error occurred with unpreparing the system
// exclusive header.
if (result != MMSYSERR_NOERROR)
{
if (SysExHeaderErrorOccurred != null)
{
OutputDeviceException ex =
new OutputDeviceException(result);
SysExHeaderErrorOccurred(this,
new SysExHeaderErrorEventArgs(ex.Message));
}
}
// Free memory allocated for the system exclusive data.
Marshal.FreeHGlobal(header.data);
}
}
}
/// <summary>
/// Sends system exclusive messages.
/// </summary>
/// <param name="message">
/// The system exclusive message to send.
/// </param>
public void Send(SysExMessage message)
{
// Guard.
if (!IsOpen())
{
return;
}
// Create header.
MidiHeader header = new MidiHeader();
// System exclusive message data.
string msg = message.Message;
//
// Initialize header.
//
header.data = Marshal.StringToHGlobalAnsi(msg);
header.bufferLength = msg.Length;
header.flags = 0;
// Prepare header.
ThrowOnError(midiOutPrepareHeader(handle, ref header,
Marshal.SizeOf(header)));
// Place header in queue to be retrieved later.
syncHeaderQueue.Enqueue(header);
// Send message.
ThrowOnError(midiOutLongMsg(handle, ref header,
Marshal.SizeOf(header)));
// System exclusive messages cancel running status.
runningStatus = 0;
}
private static extern int midiOutUnprepareHeader(int handle,
ref MidiHeader midiHeader, int sizeOfmidiHeader);
private static extern int midiOutLongMsg(int handle,
ref MidiHeader midiHeader, int sizeOfmidiHeader);
/// <summary>
/// Sends system exclusive messages.
/// </summary>
/// <param name="message">
/// The system exclusive message to send.
/// </param>
public void Send(SysExMessage message)
{
// Guard.
if(!IsOpen())
return;
// Create header.
MidiHeader header = new MidiHeader();
// System exclusive message data.
string msg = message.Message;
//
// Initialize header.
//
header.data = Marshal.StringToHGlobalAnsi(msg);
header.bufferLength = msg.Length;
header.flags = 0;
// Prepare header.
ThrowOnError(midiOutPrepareHeader(handle, ref header,
Marshal.SizeOf(header)));
// Place header in queue to be retrieved later.
syncHeaderQueue.Enqueue(header);
// Send message.
ThrowOnError(midiOutLongMsg(handle, ref header,
Marshal.SizeOf(header)));
// System exclusive messages cancel running status.
runningStatus = 0;
}
private static extern int midiOutLongMsg(int handle,
ref MidiHeader midiHeader, int sizeOfmidiHeader);
private static extern int midiOutUnprepareHeader(int handle,
ref MidiHeader midiHeader, int sizeOfmidiHeader);
/// <summary>
/// Handles triggering the system exclusive message received event.
/// </summary>
/// <param name="header">
/// Midi header containing the system exclusive message.
/// </param>
/// <param name="timeStamp">
/// Number of milliseconds that have passed since the input device
/// began recording.
/// </param>
private void DispatchSysExMessage(MidiHeader header, int timeStamp)
{
// Create array for holding system exclusive data.
byte[] data = new byte[header.bytesRecorded - 1];
// Get status byte.
byte status = Marshal.ReadByte(header.data);
// Copy system exclusive data into array (status byte is
// excluded).
for(int i = 1; i < header.bytesRecorded; i++)
{
data[i - 1] = Marshal.ReadByte(header.data, i);
}
// Create message.
SysExMessage msg = new SysExMessage((SysExType)status, data);
// Raise event.
SysExReceived(this, new SysExEventArgs(msg, timeStamp));
}
