References ▼
typedef struct _LTWAINPROPERTYQUERY{L_UINT uStructSize;L_UINT uType;union{pTW_ONEVALUE pltwOneValue;pTW_RANGE pltwRange;pTW_ENUMERATION pltwEnumeration;pTW_ARRAY pltwArray;};} LTWAINPROPERTYQUERY, * pLTWAINPROPERTYQUERY;
The LTWAINPROPERTYQUERY structure provides information about the capability properties.
| Member | Description | |
| uStructSize | Size of this structure in bytes, for versioning. Use the sizeof() macro to calculate this value. | |
| uType | Holds the type of pointer to use from the union. Possible values are (according to the TWAIN 1.9 specification): | |
| Value | Meaning | |
| TWON_ONEVALUE | The container is of type TW_ONEVALUE and only the pltwOneValue pointer is used. | |
| TWON_RANGE | The container is of type TW_RANGE and only the pltwRange pointer is used. | |
| TWON_ONEVALUE | The container is of type TW_ENUMERATION and only the pltwEnumeration pointer is used. | |
| TWON_ONEVALUE | The container is of type TW_ARRAY and only the pltwArray pointer is used. | |
| pltwOneValue | Pointer to a TW_ONEVALUE structure. | |
| pltwRange | Pointer to a TW_RANGE structure. | |
| pltwEnumeration | Pointer to a TW_ENUMERATION structure. | |
| pltwArray | Pointer to a TW_ARRAY structure. | |
pLTWAINPROPERTYQUERY is a pointer to an LTWAINPROPERTYQUERY structure. Where the function parameter type is pLTWAINPROPERTYQUERY, you can declare an LTWAINPROPERTYQUERY variable, update the structure's fields, and pass the variable's address in the parameter. Declaring a pLTWAINPROPERTYQUERY variable is necessary only if your program requires a pointer.
LTWAINPROPERTIES is allocated by the L_TwainQueryProperty function and freed by L_TwainFreePropQueryStructure function.