viVPrintf
Syntax
viVPrintf(ViSession vi, ViString writeFmt, ViVAList params);
Description
This function converts, formats, and sends params to the device as specified by the format string. This function is similar to viPrintf, except that the ViVAList parameters list provides the parameters rather than separate arg parameters.
Using viVPrintf in Visual Basic 6
Some of viPrintf's variable arguments are references to primitive (byte, integer, long, float, etc.) types, meaning that the values themselves can be changed by the function. There is no equivalent in VB6 for variable argument lists with reference arguments, so no direct translation is available. Instead, use viVPrintf in conjunction with the undocumented VB6 VarPtr function to create an array of pointers to arguments than can be passed to the VISA functions. See viVPrintf/viVScanf Example using String for sample VB6 code.
Parameters
|
Name |
Dir |
Type |
Description |
|---|---|---|---|
|
vi |
IN |
ViSession |
Unique logical identifier to a session. |
|
writeFmt |
IN |
ViString |
The format string to apply to parameters in ViVAList. See viPrintf for description. |
|
params |
IN |
ViVAList |
A list containing the variable number of parameters on which the format string is applied. The formatted data is written to the specified device. |
Return Values
|
Type ViStatus |
This is the function return status. It returns either a completion code or an error code as follows. |
|
Completion Code |
Description |
|---|---|
|
VI_SUCCESS |
Parameters were successfully formatted. |
|
Error Code |
Description |
|
VI_ERROR_ALLOC |
The system could not allocate a formatted I/O buffer because of insufficient resources. |
|
VI_ERROR_INV_FMT |
A format specifier in the writeFmt string is invalid. |
|
VI_ERROR_INV_SESSION |
The given session or object reference is invalid (both are the same value). |
|
VI_ERROR_IO |
Could not perform write function because of I/O error. |
|
VI_ERROR_NSUP_FMT |
A format specifier in the writeFmt string is not supported. |
|
VI_ERROR_RSRC_LOCKED |
Specified operation could not be performed because the resource identified by vi has been locked for this kind of access. |
|
VI_ERROR_TMO |
Timeout expired before write function completed. |