Delphi hexadecimal conversion

1. hextobin () hexadecimal conversion binary
Unit: Classes
Delphi Syntax:

function HexToBin(Text, Buffer: PChar; BufSize: Integer): Integer

Description:
Call the hextobin function to convert the hexadecimal string to the corresponding binary value.
Text is a string that represents the hexadecimal value.
Buffer returns the converted binary result value.
Buffersize indicates the buffer size. Text must point to at least 2 x bufsize hexadecimal characters, because every two hexadecimal characters are expressed as one byte.
Hextobin is returned in the buffer because the text does not contain valid hexadecimal characters ('0'... 'F') and the number of characters has not yet been used.
Note: lowercase characters must be used in hexadecimal notation. hextobind cannot recognize uppercase characters.

2. bintohex () binary conversion hexadecimal
Unit: Classes
Delphi Syntax:

procedure BinToHex(Buffer, Text: PChar; BufSize: Integer);

Description:
Call bintohex to convert the binary value in the buffer to the hexadecimal string it represents.
Buffer is a byte buffer, which contains binary values.
Text returns a string ending with null, indicating the value of buffer as the hexadecimal number.
Bufsize indicates the buffer size. Text must point to a series of characters, which must contain at least 2 * bufsize bytes.

3. inttohex () converts an integer to a hexadecimal number.
Unit: sysutils
Delphi Syntax:

function IntToHex(Value: Integer; Digits: Integer): string; overload; function IntToHex(Value: Int64; Digits: Integer): string; overload;

Description:
Inttohex converts a number to a string in hexadecimal format. Value is the number to be converted. The digits parameter specifies the minimum character width. If the minimum width is insufficient, it is filled with 0.

4. convert a strtoint () string to an integer.
Unit: sysutils
Delphi Syntax:

function StrToInt(const S: string): Integer;

Description:
Returns the string s to an integer. If the string is not expressed as an integer, an exception occurs. to convert a hexadecimal string to an integer, add $ before the string.

5. convert an integer into a binary string.

function IntToBinaryStr(TheVal: LongInt): string; var counter: LongInt; begin   {This part is here because we remove leading zeros.  That means that a zero value would return an empty string.}   if TheVal = 0 then begin     result := '0';     exit;   end;   result := '';   counter := $80000000;   {Suppress leading zeros}   while  ((counter and TheVal) = 0) do begin     counter := counter shr 1;     if (counter = 0) then break; {We found our first "1".}   end;   while counter > 0 do begin     if (counter and TheVal) = 0 then result := result + '0'     else  result := result + '1';     counter := counter shr 1;   end; end; // Binary to Integer function BinToInt(Value: string): Integer; var i, iValueSize: Integer; begin   Result := 0;   iValueSize := Length(Value);   for i := iValueSize downto 1 do   if Value[i] = '1' then Result := Result + (1 shl (iValueSize - i)); end; // Integer to Binary function IntToBin(Value: Longint; Digits: Integer): string; var i: Integer; begin   Result := '';   for i := Digits downto 0 do   if Value and (1 shl i) <> 0 then   Result := Result + '1'   else   Result := Result + '0'; end;

6. hexadecimal conversion binary

function HexToBin(Hexadecimal: string): string; const BCD: array [0..15] of string = ('0000', '0001', '0010', '0011', '0100', '0101', '0110', '0111', '1000', '1001', '1010', '1011', '1100', '1101', '1110', '1111'); var i: integer; begin   for i := Length(Hexadecimal) downto 1 do   Result := BCD[StrToInt('$' + Hexadecimal[i])] + Result; end;

7. octal and decimal conversion

function OctToInt(Value: string): Longint; var i: Integer; int: Integer; begin   int := 0;   for i := 1 to Length(Value) do   begin     int := int * 8 + StrToInt(Copy(Value, i, 1));   end;   Result := int; end; function IntToOct(Value: Longint; digits: Integer): string; var rest: Longint; oct: string; i: Integer; begin   oct := '';   while Value <> 0 do   begin     rest  := Value mod 8;     Value := Value div 8;     oct := IntToStr(rest) + oct;   end;   for i := Length(oct) + 1 to digits do   oct := '0' + oct;   Result := oct; end;