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GetOrdProp function

In unit TypInfo

Get the value of an ordinal property.

Declaration

pascal
function GetOrdProp(Instance: TObject; PropInfo: PPropInfo): Int64

Description

GetOrdProp returns the value of the ordinal property described by PropInfo or with name PropName for the object Instance. The value is returned as a longint, which should be typecast to the needed type.

Ordinal properties that can be retrieved include:

Integers and subranges of integers
The value of the integer will be returned.
Enumerated types and subranges of enumerated types
The ordinal value of the enumerated type will be returned.
Sets
If the base type of the set has less than 31 possible values. If a bit is set in the return value, then the corresponding element of the base ordinal class of the set type must be included in the set.

Errors

No checking is done whether Instance is non-nil, or whether PropInfo describes a valid ordinal property of Instance Specifying an invalid property name in PropName will result in an EPropertyError exception.

See also

Example: ex1

pascal
program example1;

{ This program demonstrates the GetOrdProp function }

{$mode objfpc}

uses rttiobj,typinfo;

Var
  O : TMyTestObject;
  PI : PPropInfo;

begin
  O:=TMyTestObject.Create;
  Writeln('Boolean property    : ');
  Writeln('Value               : ',O.BooleanField);
  Writeln('Ord(Value)          : ',Ord(O.BooleanField));
  Writeln('Get (name)          : ',GetOrdProp(O,'BooleanField'));
  PI:=GetPropInfo(O,'BooleanField');
  Writeln('Get (propinfo)      : ',GetOrdProp(O,PI));
  SetOrdProp(O,'BooleanField',Ord(False));
  Writeln('Set (name,false)    : ',O.BooleanField);
  SetOrdProp(O,PI,Ord(True));
  Writeln('Set (propinfo,true) : ',O.BooleanField);
  O.Free;
end.

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.