Hand Held Products 4X00 - Manual (Page 82)

2 - 68 IMAGETEAM™ 4X00 Series Software Development Kit (SDK) User’s Guide
Parameters
dwTimeout
Time in milliseconds that the engine scans until finding a decode. The timeout value must be greater than zero.
pchMessage
Upon successful return, this variable points to the decoded message. The caller should allocate enough memory for
this buffer to hold the largest possible decode message. See
oemGetMaxMessageChars (page 2-12).
pchCodeID
Upon successful return, this variable points to the Hand Held Products Code ID for the decoded symbology. See
Symbology Identifiers (page 3-1).
pchAIMID
Upon successful return, this variable points to the AIM ID for the decoded symbology. See Symbology Identifiers (page
3-1).
pchSymModifier
Upon successful return, this variable points to the code modifier for the decoded symbology. See Symbology Identifiers
(page 3-1).
pnLength
Upon successful return, this variable points to the length of the bar code data that was captured. The length is
represented in terms of the number of TCHAR characters in the TCHAR *pchMessage.
fpCallBack
Pass in this pointer to a parameterless BOOL-returning function to allow for an external event that causes a return from
oemWaitForDecode. As long as the function pointed to by fpCallBack returns TRUE, oemWaitForDecode continues to
attempt to decode a symbol. If the function pointed to by fpCallBack returns FALSE, then oemWaitForDecode returns
with a Result_t of RESULT_ERR_NOTRIGGER. OemWaitForDecode also returns if it gets a valid decode or the
dwTimeout occurs. Setting the parameter to NULL prevents the API from calling this callback function. In that case,
oemWaitForDecode only returns after a valid decode of dwTimeout has passed without a successful decode.
oemWaitForDecodeRaw
This function causes the engine to start scanning for a decodable symbol. This function does not return until either a symbol is
decoded, or the timeout period has elapsed. If a message was decoded, it is returned in this function's parameters in raw form
as byte values.
Result_t oemWaitForDecodeRaw (
DWORD dwTimeout,
BYTE *pchMessage,
BYTE *pchCodeID,
BYTE *pchAIMID,
BYTE *pchSymModifier,
WORD *pnLength,
BOOL (*fpCallBack) (void)
)
Return Values
RESULT_SUCCESS
RESULT_ERR_ENGINEBUSY
RESULT_ERR_PARAMETER
RESULT_ERR_NOTRIGGER
RESULT_ERR_NODECODE
RESULT_ERR_NOIMAGE