System.TSingleRec
Delphi
TSingleRec = packed record
private
aSingle: Single;
function InternalGetBytes(Index: Cardinal): UInt8; inline;
function InternalGetWords(Index: Cardinal): UInt16; inline;
procedure InternalSetBytes(Index: Cardinal; const Value: UInt8); inline;
procedure InternalSetWords(Index: Cardinal; const Value: UInt16); inline;
function GetBytes(Index: Cardinal): UInt8; inline;
function GetWords(Index: Cardinal): UInt16; inline;
procedure SetBytes(Index: Cardinal; const Value: UInt8); inline;
procedure SetWords(Index: Cardinal; const Value: UInt16); inline;
function GetExp: UInt64; inline;
function GetFrac: UInt64; inline;
function GetSign: Boolean; inline;
procedure SetExp(NewExp: UInt64);
procedure SetFrac(NewFrac: UInt64);
procedure SetSign(NewSign: Boolean);
public
function Exponent: Integer;
function Fraction: Extended;
function Mantissa: UInt64;
property Sign: Boolean read GetSign write SetSign;
property Exp: UInt64 read GetExp write SetExp;
property Frac: UInt64 read GetFrac write SetFrac;
function SpecialType: TFloatSpecial;
procedure BuildUp(const SignFlag: Boolean; const Mantissa: UInt64; const Exponent: Integer);
class operator Explicit(a: Extended): TSingleRec; inline;
class operator Explicit(a: TSingleRec): Extended; inline;
property Bytes[Index: Cardinal]: UInt8 read GetBytes write SetBytes; // 0..3
property Words[Index: Cardinal]: UInt16 read GetWords write SetWords; // 0..1
end deprecated 'Use TSingleHelper';
C++
struct DECLSPEC_DRECORD TSingleRec
{
private:
float aSingle;
Byte __fastcall InternalGetBytes(unsigned Index);
Word __fastcall InternalGetWords(unsigned Index);
void __fastcall InternalSetBytes(unsigned Index, const Byte Value);
void __fastcall InternalSetWords(unsigned Index, const Word Value);
Byte __fastcall GetBytes(unsigned Index);
Word __fastcall GetWords(unsigned Index);
void __fastcall SetBytes(unsigned Index, const Byte Value);
void __fastcall SetWords(unsigned Index, const Word Value);
unsigned __int64 __fastcall GetExp();
unsigned __int64 __fastcall GetFrac();
bool __fastcall GetSign();
void __fastcall SetExp(unsigned __int64 NewExp);
void __fastcall SetFrac(unsigned __int64 NewFrac);
void __fastcall SetSign(bool NewSign);
public:
int __fastcall Exponent();
Extended __fastcall Fraction();
unsigned __int64 __fastcall Mantissa();
__property bool Sign = {read=GetSign, write=SetSign};
__property unsigned __int64 Exp = {read=GetExp, write=SetExp};
__property unsigned __int64 Frac = {read=GetFrac, write=SetFrac};
TFloatSpecial __fastcall SpecialType();
void __fastcall BuildUp(const bool SignFlag, const unsigned __int64 Mantissa, const int Exponent);
static TSingleRec __fastcall _op_Explicit(Extended a);
__property Byte Bytes[unsigned Index] = {read=GetBytes, write=SetBytes};
__property Word Words[unsigned Index] = {read=GetWords, write=SetWords};
};
Inhaltsverzeichnis
Eigenschaften
Typ | Sichtbarkeit | Quelle | Unit | Übergeordnet |
---|---|---|---|---|
record struct |
public | System.pas System.hpp |
System | System |
Beschreibung
Warnung: TSingleRec ist veraltet. Bitte verwenden Sie SysUtils.TSingleHelper.
TSingleRec kann Low-Level-Operationen mit Gleitkommawerten mit einfacher Genauigkeit durchführen.
Ab XE3 sind die Eigenschaften TSingleRec.Bytes und TSingleRec.Words Array-Eigenschaften. Die Operatoren System.High und System.Low können nicht für Array-Eigenschaften angewendet werden. Sie können stattdessen System.SizeOf wie im folgenden Beispiel verwenden.
Beispiel
In der XE2-Version dieses Beispiels wurde mit System.High und System.Low Byte für Byte durch TSingleRec wie folgt iteriert:
for I := High(F.Bytes) downto Low(F.Bytes) do
Im XE3-Beispiel wird System.SizeOf anstelle von High und Low verwendet:
var
F: TSingleRec;
I: Integer;
begin
F := TSingleRec(-0.5);
// display the hexadecimal representation of the single precision floating-point value
// leftmost bytes are the most significant
for I := sizeof(F) - 1 downto 0 do
Write(IntToHex(F.Bytes[I], 2) + ' ');
Writeln;
// display the value contained in the TSingleRec record
Writeln(FloatToStr(Single(F)));
// ...
Konsolenausgabe:
BF 00 00 00 -0.5