LEADTOOLS TWAIN C++ Class Library Help > Quick Reference > Data Types > LTWAINPROPERTYQUERY |
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 the LTWAINPROPERTYQUERY structure, in bytes, for versioning. Use the sizeof() macro to calculate the 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. |
Comments
pLTWAINPROPERTYQUERY is a pointer to a 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 LTwain::QueryProperty function and freed by LTwain::FreePropQueryStructure function.