Question

我想使用Code :: Blocks在C中使用ddeml.h系统头文件。当我运行我的程序时，我在系统头中出错！其中一个错误是“未知类型名称HDDEDATA”。

我真的没有太多的代码写。我刚刚开始这个项目。我想在我的实验室里自动化一些东西。我想用C与DDE Server进行通信。以下是手册中的示例。我假设我必须包含在C代码#include中。谢谢你的帮助！

实施例以下代码片段显示了如何将命令发送到Nucleus DDE 服务器。它使用Windows API DdeClientTransaction（）发送：move：relative 命令。

// The following code fragment uses Windows DDEML APIs
// to send a move command to the Nucleus DDE Server
// and receives a status string.
//
// Variables and initial values.
HCONV hConv = NULL;
DDE Server always returns responses
Client terminates DDE Server conversations
Communications Protocols • 19
DWORD idInst = 0;
HSZ hszService = NULL;
HSZ hszTopic = NULL;
HSZ hszCmd = NULL;
BOOL err = FALSE;
HDDEDATA transResult = NULL;
DWORD dwResult = 0;
char result[300];
// Need long timeout value to allow the station to move and
// respond.
const long TIMEOUT = 60000;
// Initialize the DDEML environment. Create an Instance
// that is used in many other calls to DDE.
if(DMLERR_NO_ERROR != DdeInitialize(&idInst,MyDDECallBack,
APPCMD_CLIENTONLY, 0))
err = true;
// Create String handles for the server name, topic and item.
if(!err)
{
hszService = DdeCreateStringHandle(idInst, "EDMAIN",
CP_WINANSI);
hszTopic = DdeCreateStringHandle(idInst, "CMI Commands",
CP_WINANSI);
hszCmd = DdeCreateStringHandle(idInst,
":MOVE:REL 2 100 100 NONE",
CP_WINANSI);
err = (hszService == NULL || hszTopic == NULL ||
hszCmd == NULL);
}
// Connect to the Nucleus DDE Server. (Open a conversation).
// Captain Picard would say, "Open a channel Mr. Wharf".
if(!err)
{
hConv = DdeConnect(idInst, hszService, hszTopic, NULL);
err = hConv == NULL;
if(err)
MessageBox(NULL, "Unable to make DDE connection.\n"
"Make sure Nucleus is running.",
"DDE CLIENT ERROR", MB_ICONSTOP);
}
// Send the command string to the server.
if (!err)
{
transResult = DdeClientTransaction(NULL, 0, hConv, hszCmd,
CF_TEXT, XTYP_REQUEST, TIMEOUT, NULL);
// Read the result string. TransResult will be a
// valid data handle if the client transaction above
// was successful, and NULL if it was not. This must be
// checked since calls to DdeGetData with a NULL handle
// cause GPF’s.
20 • Nucleus 4 Communications Guide
if(transResult)
DdeGetData(transResult, (LPBYTE)result,
sizeof(result), 0);
// Display the result string.
MessageBox(NULL, result,
"RESULT", MB_ICONINFORMATION);
}
// Close the conversation.
if (hConv != NULL)
DdeDisconnect( hConv );
// Delete the string handles.
if ((hszService != NULL) & (idInst != NULL))
DdeFreeStringHandle( idInst, hszService );
if ((hszTopic != NULL) & (idInst != NULL))
DdeFreeStringHandle( idInst, hszTopic );
if ((hszCmd != NULL) & (idInst != NULL))
DdeFreeStringHandle( idInst, hszCmd );
// Clear out the DDEML environment.
if (idInst != NULL)
DdeUninitialize(idInst);
..
// Since we are only doing requests from Nucleus, we don’t
// expect to get callbacks to this routine. Nevertheless,
// it is necessary to create a routine with no action.
HDDEDATA CALLBACK MyDDECallBack( UINT wType,
UINT wFmt, HCONV HConv, HSZ dataHandle1, HSZ dataHandle2,
HDDEDATA data, DWORD myword1, DWORD myword2)
{
return NULL;
}

C中的系统头文件

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