ServerDDEWrite
- Updated2023-02-21
- 2 minute(s) read
ServerDDEWrite
int ServerDDEWrite (unsigned int conversationHandle, char itemName[], unsigned int dataFormat, void *dataPointer, size_t dataSize, unsigned int timeOut);
Purpose
Allows your program, acting as a DDE server, to write data to a DDE client application when the client requests data.
Call this function only when your serverCallbackFunction receives a DDE_REQUESTDATA message. If you call the function at any other time, ServerDDEWrite stores the data until the client requests the data. If you call the function multiple times on the same conversation before the client requests the data, ServerDDEWrite appends each new data set to the buffer that contains the stored data.
If the client has a hot or warm link and you need to send data other than in response to a DDE_REQUESTDATA message, use AdviseDDEDataReady or BroadcastDDEDataReady.
If successful, ServerDDEWrite returns the number of bytes written. Otherwise, ServerDDEWrite returns a negative error code.
Parameters
| Input | ||
| Name | Type | Description |
| conversationHandle | unsigned int | The conversation handle that uniquely represents the connection between the server and the client. |
| itemName | char [] | The name that uniquely identifies the object to which the data refers; for example, an Excel cell name. Each server defines its own set of valid item names. The name must be a string of length from 1 to 255. itemName is case insensitive. |
| dataFormat | unsigned int | One of the data formats Microsoft Windows recognizes. Windows supports the following valid data formats: CF_TEXT CF_BITMAP CF_METAFILEPICT CF_SYLK CF_DIF CF_TIFF CF_OEMTEXT CF_DIB CF_PALETTE CF_PENDATA CF_RIFF CF_WAVE CF_OWNERDISPLAY CF_DSPTEXT CF_DSPBITMAP CF_DSPMETAFILEPICT Refer to www.msdn.com for more information about DDE programming and the meaning of each data format type. |
| dataPointer | void * | The pointer to the data to be written. NULL is not allowed unless dataSize is zero. |
| dataSize | size_t | The number of bytes to write. An error is returned if you pass a value greater than INT_MAX. |
| timeOut | unsigned int | The number of milliseconds to wait for a DDE read or write operation to complete. If a value of zero is passed, then a default timeout of 5000 milliseconds is used. |
Return Value
| Name | Type | Description |
| status | int | Return value indicating whether the function was successful. A negative number represents the error code. For functions that read or write data (ClientDDERead, ClientDDEWrite, ServerDDEWrite, AdviseDDEDataReady, BroadcastDDEDataReady), if the function was successful, the return value is the number of bytes transferred. For other DDE Support Library functions, zero represents successful execution. The enumerated type that specifies the absolute values of the error codes is declared in ddesupp.h. For instance, if an invalid parameter is passed, –kDDE_InvalidParameter is returned. Currently, a maximum of 255 concurrent conversations are allowed at any one time. If you exceed this limit, –kDDE_TooManyConversations will be returned. Error codes from –16 to –33 are native DDEML errors, which correspond to Windows DDE error codes starting from 0x4000. |
Additional Information
Library: DDE Support Library
Include file: ddesupp.h
LabWindows/CVI compatibility: LabWindows/CVI 3.0 and later