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How to convert byte array to its hexadecimal representation in Delphi

I have a TBytes variable with a value of [0,0,15,15]. How to convert it to "00FF"?

I do not want to use loops, bcoz use this logic in intensive work.

(I tried to use BinToHex, but I could not get it to work with a string variable.)

Thanks and respect,

Pavan.

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4 answers
// Swapping is necessary because x86 is little-endian.
function Swap32(value: Integer): Integer;
asm
  bswap eax
end;

function FourBytesToHex(const bytes: TBytes): string;
var
  IntBytes: PInteger;
  FullResult: string;
begin
  Assert(Length(bytes) = SizeOf(IntBytes^));
  IntBytes := PInteger(bytes);
  FullResult := IntToHex(Swap32(IntBytes^), 8);
  Result := FullResult[2] + FullResult[4] + FullResult[6] + FullResult[8];
end;

, , , , . , 16, . , :

Result := IntToHex(Swap32(IntBytes^), 8);

, , , . IntToHex .

+5
function ByteToHex(InByte:byte):shortstring;
const Digits:array[0..15] of char='0123456789ABCDEF';
begin
 result:=digits[InByte shr 4]+digits[InByte and $0F];
end;

Example :
MyHex := ByteTohex($FF);
the result
MyHex is "FF".

MyHex := ByteTohex(255);
the result
MyHex is "FF".

MyHex := ByteTohex($55);
the result
MyHex is "55".
+2

. BinToHex, , 0..255 , .

procedure BinToSingleHex(Buffer, Text: PAnsiChar; BufSize: Integer);
const
  Convert: array[0..15] of AnsiChar = '0123456789ABCDEF';
var
  I: Integer;
begin
  for I := 0 to BufSize - 1 do
  begin
    Text[0] := Convert[Byte(Buffer[I]) and $F];
    Inc(Text);
  end;
end;

, :

procedure BinToSingleHex(Buffer, Text: PAnsiChar; BufSize: Integer);assembler;
asm
        PUSH    ESI
        PUSH    EDI
        MOV     ESI,EAX
        MOV     EDI,EDX
        MOV     EDX,0
        JMP     @@1
@@0:    DB      '0123456789ABCDEF'
@@1:    LODSB
        AND     DL,AL
        AND     DL,0FH
        MOV     AL,@@0.Byte[EDX]
        STOSB
        DEC     ECX
        JNE     @@1
        POP     EDI
        POP     ESI
end;

:

type  THexDigit=0..15;
const ArSize=16;
var   Ar:array[0..Pred(ArSize)] of THexDigit=(0,1,2,3,4,5,6,7,8,9,8,7,6,5,4,3);
      S:Array[0..Pred(ArSize)] of AnsiChar;

BinToSingleHex(@Ar,S,Length(Ar));
WriteLn(S);
+2

, ?

const
HexChars : Array[0..15] of Char = ('0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F');

Assuming TBytes 0..15

Function (ABytea: TBytes): string
    begin 
      Result  := HexChars[ABytea[0]];
      Result  := Result + HexChars[ABytea[1]];
      Result  := Result + HexChars[ABytea[2]];
      Result  := Result + HexChars[ABytea[3]];
    end;

of course, neatly with a loop :) and needs modification for byte values ​​above 15:

begin 
  Result  := HexChars[ABytea[0] shr 4];
  Result  := Result + HexChars[ABytea[0] and $0F];
  Result  := Result + HexChars[ABytea[1] shr 4];
  Result  := Result + HexChars[ABytea[1] and $0F];
  Result  := Result + HexChars[ABytea[2] shr 4];
  Result  := Result + HexChars[ABytea[2] and $0F];
  Result  := Result + HexChars[ABytea[3] shr 4];
  Result  := Result + HexChars[ABytea[3] and $0F];
end;

Even tidier with a loop, especially if TBytes gets bigger

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