Titus Information Systems CDDE Class

Titus Information Systems, Inc.

Standard Library
CDDE Class

This base class is the foundation for providing easy access to Dynamic Data Exchange (DDE) functions. Note that, since most member functions and variables are static, there can be only one instance of this class in an application. In other words, using CDDE as a base class will restrict the application to being either a DDE server or a DDE client, but not both. The member functions and variables are as follows:

CDDE::CDDE(): This is the constructor. It initializes the data members.
static HDDEDATA CALLBACK CDDE::DdeCallback(UINT TranType, UINT Format, HCONV Caller, HSZ StringOne, HSZ StringTwo, HDDEDATA Memory, DWORD DataOne, DWORD DataTwo): This member function must be overridden by an inherited class in order to process incoming DDE transactions. It encapsulates the DdeCallback DDE function. It is activated by both the DdeClient::Open() and the DdeServer::Open() functions. The base class version returns the DDE_FNOTPROCESSED code in all cases.
static BOOL CDDE::MessageLastError(): This member function is available to inherited classes. It sets the CDDE::ErrorMessage variable to the text of the last error that occurred.
static HCONV CDDE::Conversation: This data member is available to inherited classes to store the Conversation handle of the DDE session.
static CString CDDE::ErrorMessage: This public data member contains the text of the last error. It may be displayed in a message box for the user or written to a log file.
static DWORD CDDE::InstId: This data member is available to inherited classes to store the Instance ID of the DDE session.
static int CDDE::Result: This data member is available to inherited classes to store the return code from API function calls. It is used by the CDDE::MessageLastError() function to determine the appropriate text to place in the CDDE::ErrorMessage variable.
static HSZ CDDE::Service: This data member is available to inherited classes to store the Service handle of the DDE session.