GetFieldID

PowerBuilder Native Interface

IPB_Session interface:

GetFieldID method

Description

Obtains the internal ID of a class instance variable.

Syntax

GetFieldID(pbclass cls, LPCTSTR fieldName)

Argument	Description
cls	The class in which the field resides
fieldName	The instance member name, in lowercase

Return Values

pbfieldID or 0xffff if a field ID cannot be found.

Examples

This function obtains the identifier of a class's visible field, if it exists, and uses it to set the value of the field:

void CallBack::f_setvisible(IPB_Session* session,
   pbobject dwobj)
{
   pbclass cls;
   IPB_Value* pv;
   pbfieldID fid;
   pbstring strtmp;
   bool isTrue;
   pbboolean isNull;
 
   cls = session-> GetClass(dwobj);
   fid = session-> GetFieldID(cls, "visible");
   if (fid == kUndefinedFieldID) 
      return;
   isTrue = session-> GetBoolField(dwobj, fid, isNull); 
   if (isTrue)
      session -> SetBoolField(dwobj, fid, false);
    else
      session -> SetBoolField(dwobj, fid, true);
    return ;
}

Usage

GetFieldID is one of a set of functions that allows native code to access the fields of Java objects and get and set their values. You use GetFieldID to retrieve the value of a field, specifying the class name and the field name. The field ID returned can be used as an argument to the related functions.