LVectorVertex::LockObject

#include "ltwrappr.h"

virtual L_INT LVectorVertex::LockObject(pVertex)

Gets the object information of the class object.

Parameters

pVECTORVERTEX pVertex

Pointer to a VECTORVERTEX structure to be updated with the vector object information.

Returns

Value Meaning
SUCCESS The function was successful.
< 1 An error occurred. Refer to Return Codes.

Comments

This function is used to retrieve the object information of the class object.

To use this method, declare a variable of the VECTORVERTEX type and pass the address to this function. After modifying the vector object settings, call LVectorVertex::UnlockObject (). LVectorVertex::LockObject() and LVectorVertex::UnlockObject () should always be called in pairs.

Before an object has been added to the LVectorBase object, using LVectorBase::AddObject or LVectorLayer::AddObject, LVectorVertex::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 LVectorVertex::UnlockObject ().However, as long as the number of points does not change, the coordinates of the individual points can always be modified using LVectorVertex::UnlockObject().

To change the object information for a class object, call LVectorVertex::UnlockObject.

LVectorVertex::LockObject and LVectorVertex::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, LVectorVertex::LockObject and LVectorVertex::UnlockObject will return WRPERR_VECTOR_INVALID_OBJECT_TYPE. Object properties can still be inspected and changed by using LVectorObject::GetObjectAttributes and LVectorObject::SetObjectAttributes.

Required DLLs and Libraries

See Also

Functions

Topics

Example

This example will add a new green vertex to the Active Layer LVectorBase object
Once added, the color will be changed to blue

L_INT LVectorVertex__LockObjectExample(HWND hWnd, LVectorBase *pVector) 
{ 
   UNREFERENCED_PARAMETER(hWnd); 
 
   L_INT          nRet; 
   VECTORVERTEX   Vertex; 
 
   //Create Vertex Object 
   Vertex.Point.x = 50; 
   Vertex.Point.y = 50; 
   Vertex.Point.z = 10; 
 
   Vertex.Pen.bExtPen = FALSE; 
   Vertex.Pen.nSize = sizeof( VECTORPEN ); 
   Vertex.Pen.NewPen.LogPen.lopnStyle = PS_SOLID; 
   Vertex.Pen.NewPen.LogPen.lopnWidth.x = 10; 
   Vertex.Pen.NewPen.LogPen.lopnWidth.y = 10; 
   Vertex.Pen.NewPen.LogPen.lopnColor = RGB(0,255,0); 
 
   LVectorVertex VectorVertex(&Vertex); 
 
   nRet = pVector->AddObject(&VectorVertex); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   //Now change color to blue 
   MessageBox(NULL, TEXT("Changing color to red"), TEXT(""), MB_OK); 
 
   VECTORVERTEX VertexTemp; 
 
   nRet = VectorVertex.LockObject(&VertexTemp); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   VertexTemp.Pen.bExtPen = FALSE; 
   VertexTemp.Pen.NewPen.LogPen.lopnColor = RGB(255,0,0); 
   nRet = VectorVertex.UnlockObject(&VertexTemp); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   //LVectorVertex destructor called when VectorVertex goes out of scope 
 
   return SUCCESS; 
} 

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