Using NDdeShareAdd to Create a DDE Share

The NDdeShareAdd function is used by a DDE server application to create a DDE share.

Before creating a DDE share, it is a good idea to verify that the proposed share name and topic name are valid by using the NDdeIsValidShareName and NDdeIsValidAppTopicList functions. These functions are also called by NDdeShareAdd.

The following example demonstrates how to create a DDE share. It uses a NULL discretionary access control list (DACL) to grant write access to all users. Note that this is not the same as specifying NULL in the pSD parameter of NDdeShareAdd.

BOOL MyCreateDdeShare( LPTSTR lpszShareName, LPTSTR lpszTopicList )

{

NDDESHAREINFO ndsi;

PSECURITY_DESCRIPTOR pSD = NULL;

// Where lpszShareName is the share name.

if( NDdeIsValidShareName( lpszShareName ) == FALSE )

return FALSE;

// Where lpszTopicList is a list of null-terminated strings terminated

// by another null character.

if( NDdeIsValidAppTopicList( lpszTopicList ) == FALSE )

return FALSE;

// Fill in the NDDESHAREINFO structure.

ndsi.lRevision = 1;

ndsi.lpszShareName = lpszShareName;

ndsi.lShareType = SHARE_TYPE_STATIC;

ndsi.lpszAppTopicList = lpszTopicList;

ndsi.fSharedFlag = TRUE;

ndsi.fService = FALSE;

ndsi.fStartAppFlag = TRUE;

ndsi.nCmdShow = SW_SHOWNORMAL;

ndsi.cNumItems = 0;

ndsi.lpszItemList = "";

// Create a security descriptor to allow write access.

pSD = (PSECURITY_DESCRIPTOR) LocalAlloc(

LPTR,

SECURITY_DESCRIPTOR_MIN_LENGTH );

InitializeSecurityDescriptor( pSD, SECURITY_DESCRIPTOR_REVISION );

SetSecurityDescriptorDacl( pSD, TRUE, (PACL)NULL, FALSE );

// Delete possible old DDE share.

NDdeShareDel(

NULL,

lpszShareName,

0

);

// Create the DDE share.

NDdeShareAdd(

NULL,

2,

pSD,

(LPBYTE)&ndsi,

sizeof(NDDESHAREINFO)

);

LocalFree( pSD );

return TRUE;

}

The following example shows how you could call the MyCreateDdeShare function to create the share MyDdeShare$:

char *TopicList = "\0\0MyApp|MyTopic\0\0";

MyCreateDdeShare( "MyDdeShare$", TopicList );

This share name ends with a dollar sign ($), indicating that it is a static DDE share. Topic strings are provided only for the static-type DDE share.

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