private void SendToChannel(string channelName, string message)
{
Validate.That(channelName).IsNotNullOrEmpty();
Validate.That(message).IsNotNullOrEmpty();
// create a DataGram instance, and ensure memory is freed
using (var dataGram = new WinMsgDataGram(channelName, message))
{
// Allocate the DataGram to a memory address contained in COPYDATASTRUCT
Native.COPYDATASTRUCT dataStruct = dataGram.ToStruct();
// Use a filter with the EnumWindows class to get a list of windows containing
// a property name that matches the destination channel. These are the listening
// applications.
var filter = new WindowEnumFilter(MessageListener.GetChannelKey(channelName));
var winEnum = new WindowsEnum(filter.WindowFilterHandler);
foreach (var hWnd in winEnum.Enumerate())
{
IntPtr outPtr;
// For each listening window, send the message data. Return if hang or unresponsive within 1 sec.
Native.SendMessageTimeout(hWnd, Native.WM_COPYDATA, IntPtr.Zero, ref dataStruct,
Native.SendMessageTimeoutFlags.SMTO_ABORTIFHUNG, 1000, out outPtr);
}
}
}
/// <summary>
/// Constructor creates an instance of the class from a pointer address, and expands
/// the data packet into the originating channel name and message.
/// </summary>
/// <param name = "lpParam">A pointer the a COPYDATASTRUCT containing information required to
/// expand the DataGram.</param>
private WinMsgDataGram(IntPtr lpParam)
{
allocatedMemory = false;
dataStruct = (Native.COPYDATASTRUCT)Marshal.PtrToStructure(lpParam, typeof(Native.COPYDATASTRUCT));
var bytes = new byte[dataStruct.cbData];
Marshal.Copy(dataStruct.lpData, bytes, 0, dataStruct.cbData);
string rawmessage;
using (var stream = new MemoryStream(bytes))
{
var b = new BinaryFormatter();
rawmessage = (string)b.Deserialize(stream);
}
dataGram = JsonConvert.DeserializeObject <DataGram>(rawmessage);
}
/// <summary>
/// Constructor which creates the data gram from a message and channel name.
/// </summary>
/// <param name = "serializer"></param>
/// <param name = "channel">The channel through which the message will be sent.</param>
/// <param name = "message">The string message to send.</param>
internal WinMsgDataGram(string channel, string message)
{
allocatedMemory = false;
dataStruct = new Native.COPYDATASTRUCT();
dataGram = new DataGram(channel, message);
}