References ▼
typedef struct _LWIADATATRANSFER{L_UINT uStructSize;GUID * pguidFormat;L_INT nCompression;L_INT nTransferMode;L_INT nImageDataType;} LWIADATATRANSFER, * pLWIADATATRANSFER;
The LWIADATATRANSFER structure provides information about data transfer.
| Member | Description | |
| uStructSize | Size of this structure in bytes, for versioning. Use the sizeof() macro to calculate this value. | |
| pguidFormat | Contains the preferred format of the image when transferred from the device. | |
| For a list of all available transfer formats refer to Microsoft Windows SDK Documentation for the WIA_IPA_FORMAT property ID. | ||
| nCompression | Contains the preferred compression type to be used when transferring data from the device. | |
| For a list of all available compressions refer to Microsoft Windows SDK Documentation for the WIA_IPA_COMPRESSION property ID. | ||
| nTransferMode | Transfer mode to be used by the WIA source. Possible values are: | |
| Value | Meaning | |
| TYMED_CALLBACK | Memory buffered transfer mode. The source will be transferring strips of data to the application according to the buffer size given. This is the default value. | |
| TYMED_FILE | File transfer mode. This will use the specified file in the szFileName member of the LWIAACQUIREOPTIONS structure passed to any of the available acquire functions. | |
| Make sure that the passed transfer format in the pguidFormat member of this structure is the same as the one specified through the LWIAACQUIREOPTIONS structure since the acquire functions will always use the one passed through the LWIAACQUIREOPTIONS structure. | ||
| nImageDataType | Contains the preferred data type for the image when transferred from the device. | |
| For a list of all available compressions refer to Microsoft Windows SDK Documentation for the WIA_IPA_DATATYPE property ID. | ||
This feature is available in LEADTOOLS version 16 or higher.
pLWIADATATRANSFER is a pointer to a LWIADATATRANSFER structure. If the function parameter type is pLWIADATATRANSFER, you can declare a LWIADATATRANSFER variable, update the structure's fields and pass the variable's address in the parameter. Declaring a pLWIADATATRANSFER variable is necessary only if your program requires a pointer.
LWIADATATRANSFER is used with the LWIAPROPERTIES structure.
If the nTransferMode member value is set to TYMED_CALLBACK, the acquire functions will use the memory buffers received from the scanner, and generate a BITMAPHANDLE as a result.
This generated BITMAPHANDLE will be returned in the pBitmap parameter of LWia::AcquireCallBack callback when it is fired by calling the LWia::Acquire or LWia::AcquireSimple functions.