DTWAIN_SetCustomDSData

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The DTWAIN_SetCustomDSData sets the custom data of a Source.

 

HANDLE DTWAIN_SetCustomDSData (

DTWAIN_SOURCE

Source,

HANDLE

hData,

LPBYTE

pData,

LONG

nSize,

LONG

nFlags );

 

Parameters:

Source

An open TWAIN Source.

 

hData

Specifies the global handle to the data, or NULL

 

pData

Specifies the address of where the Source data is located or NULL.

 

nSize

Specifies the number of bytes to copy from pData.  If pData is NULL, this argument is ignored.

 

nFlags

Flags to determine how to interpret the hData and pData arguments.

 

Returns:

TRUE if successful, otherwise FALSE is returned.

 

Comments:

DTWAIN_SetCustomDSData uses the DAT_CUSTOMDSDATA TWAIN Data type to set the Source's custom data.  The Source must support setting of custom data.  To test if the Source supports custom data, call DTWAIN_IsCustomDSDataSupported.  Usually mid to high-volume scanners support this type of operation.

 

Note:  The format of the data sent to the Source is Source dependent and is not defined by TWAIN, therefore your application must have knowledge of the format of the data from the creator of the Source.  Usually the manufacturer of the device has specifications as to what format the data is to send and how to interpret the data..

 

If the value of nFlags is DTWAINSCD_USEHANDLE, the hData argument is the HANDLE to Globally Locked memory that contains the Source data.  The handle must be created with the Windows API GlobalAlloc function.  The pData and nSize arguments are ignored if DTWAINSCD_USEHANDLE is specified.

 

If nFlags is DTWAINSCD_USEDATA, the hData argument is ignored, and the Source data is located at pData.  The length of the data located at pData is specified by the nSize argument.  If the application does not desire to do the memory management, this method should be used.

 

Setting the Source's custom data is usually done after the application calls the DTWAIN_ShowUIOnly  and then DTWAIN_GetCustomDSData.

 

TWAIN State Transitions

The Source must be in State 4 or higher

 

Prerequisite Function Call(s)

DTWAIN_SysInitialize

 

DTWAIN Source Selection Function

 

 

See Also

Setting / Getting Source Custom Data

Retrieving / Setting Custom Source Data