/// <summary>
/// Initiates a conversation.
/// </summary>
/// <param name="service">Service (or application name) we're connecting to.</param>
/// <param name="topic">Topic to request the server for.</param>
internal DdeConversation(Dde dde, string service, string topic)
{
_dde = dde;
/*
* // Describe the conversation
* Dde.CONVCONTEXT cc;
* cc.cb = (uint)Marshal.SizeOf(typeof(Dde.CONVCONTEXT));
* cc.wFlags = 0u;
* cc.wCountryID = 0u;
* cc.iCodePage = Win32Declarations.CP_WINANSI;
* cc.dwLangID = 0u;
* cc.dwSecurity = 0u;
* cc.qos.Length = (uint)Marshal.SizeOf(typeof(Dde.SECURITY_QUALITY_OF_SERVICE));
* cc.qos.ImpersonationLevel = Dde.SECURITY_IMPERSONATION_LEVEL.SecurityAnonymous;
* cc.qos.ContextTrackingMode = Dde.SECURITY_CONTEXT_TRACKING_MODE.SECURITY_STATIC_TRACKING;
* cc.qos.EffectiveOnly = 1;
*/
using (DdeString dsService = new DdeString(_dde, service))
using (DdeString dsTopic = new DdeString(_dde, topic))
_handle = Dde.DdeConnect(_dde.Instance, dsService.Handle, dsTopic.Handle, IntPtr.Zero);
if (_handle == IntPtr.Zero)
{
throw new DdeException("Could not start the DDE conversation.", _dde.GetLastError());
}
}
/// <summary>
/// Initializes the object from a handle, takes ownership over the handle, and extracts a string value as it's needed.
/// <c>Null</c> is a valid value for the handle, will cause a <c>Null</c> string to be returned.
/// </summary>
public DdeString(Dde dde, HSZ handle)
{
_dde = dde;
_handle = handle;
_dde.KeepStringHandle(handle);
_release = handle != IntPtr.Zero;
}
public void Dispose()
{
if ((_handle != IntPtr.Zero) && (_dde != null))
{
if (!Dde.DdeDisconnect(_handle))
{
throw new DdeException("Could not terminate the conversation.", _dde.GetLastError());
}
_handle = IntPtr.Zero;
_dde = null;
}
GC.SuppressFinalize(this);
}
/// <summary>
/// Initiates a synchronous DDE transaction, using the timeout value specified.
/// If the timeout expires, an exception is thrown.
/// </summary>
/// <param name="item">Item name for which the transaction is executed.</param>
/// <param name="data">Data to be exchanged during the transaction.</param>
/// <param name="timeout">Specifies the maximum length of time, in milliseconds, that the client will wait for a response from the server application in a synchronous transaction.</param>
public void StartTransaction(string item, string data, DWORD timeout)
{
Dde.CheckOwnerThread();
byte[] arDataBuffer = data != null?Encoding.ASCII.GetBytes(data) : null;
DWORD dwResult = 0;
using (DdeString dsItem = new DdeString(_dde, item))
{
if (Dde.DdeClientTransaction(arDataBuffer, (uint)(arDataBuffer != null ? arDataBuffer.Length : 0), _handle, dsItem.Handle, 0, Dde.DdeTransaction.XTYP_EXECUTE, timeout, ref dwResult) == IntPtr.Zero)
{
throw new DdeException("Could start a DDE transaction.", _dde.GetLastError());
}
}
}
/// <summary>
/// Initializes the object from a string. The handle will be generated upon a request.
/// <c>Null</c> is a valid value for a string, will cause a <c>Null</c> handle to be returned.
/// </summary>
public DdeString(Dde dde, string text)
{
_string = text;
_dde = dde;
}
