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.
Size of the LTWAINPROPERTYQUERY structure, in bytes, for versioning. Use the sizeof() operator to calculate the value.
Holds the type of pointer to use from the union. Possible values are (according to the TWAIN 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. |
Pointer to a TW_ONEVALUE structure.
Pointer to a TW_RANGE structure.
Pointer to a TW_ENUMERATION structure.
Pointer to a TW_ARRAY structure.
pLTWAINPROPERTYQUERY is a pointer to a LTWAINPROPERTYQUERY structure. If 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 LTwain::QueryProperty function and freed by LTwain::FreePropQueryStructure function.