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Gets the object information of the class object.
#include "ltwrappr.h"
virtual L_INT LVectorPolyline::LockObject(pPolyLine)
Pointer to a VECTORPOLYLINE structure to be updated with the vector object information.
| Value | Meaning |
|---|---|
| SUCCESS | The function was successful. |
| < 1 | An error occurred. Refer to Return Codes. |
This function is used to retrieve the object information of the class object.
To use this method, declare a variable of the VECTORPOLYLINE type and pass the address to this function. After modifying the vector object settings, call LVectorPolyline::UnlockObject (). LVectorPolyline::LockObject () and LVectorPolyline::UnlockObject () should always be called in pairs.
Before an object has been added to the LVectorBase object, using LVectorBase::AddObject or LVectorLayer::AddObject, LVectorPolyline::UnlockObject () can be used to change ALL properties of an object. However, once the object has been added to the LVectorBase object, some properties cannot be changed using LVectorPolyline::UnlockObject ().However, as long as the number of points does not change, the coordinates of the individual points can always be modified using LVectorPolyline::UnlockObject ().
To change the object information for a class object, call LVectorPolyline::UnlockObject.
LVectorPolyline::LockObject and LVectorPolyline::UnlockObject must be called in pairs.
Note that rotating an object may change the object type. However, not all object types are changed by rotation, and not all rotations result in changing an object type. For example, a rectangle rotated 90 degrees about the z-axis is still a rectangle. A rectangle rotated 45 degrees about the z-axis becomes a polydraw object. The table below indicates object types that may change following rotation and the possible resulting object types.
| Original object type | Possible object type following rotation |
|---|---|
| VECTOR_RECTANGLE | VECTOR_POLYGON |
| VECTOR_ELLIPSE | VECTOR_POLYDRAW |
| VECTOR_CIRCLE | VECTOR_POLYDRAW |
| VECTOR_ARC | VECTOR_POLYDRAW |
| VECTOR_TEXT | VECTOR_POLYDRAW |
| VECTOR_PIE | VECTOR_POLYDRAW |
If an object type changes, LVectorPolyline::LockObject and LVectorPolyline::UnlockObject will return WRPERR_VECTOR_INVALID_OBJECT_TYPE. Object properties can still be inspected and changed by using LVectorObject::GetObjectAttributes and LVectorObject::SetObjectAttributes.
For an example, refer to LVectorObject::UnlockObject.