delphi intToHex

看了下10.3.2版intToHex等，跟之前的xe版比较，去掉了汇编，我试了下，变慢了好多，自己写些了个，纯pascal版，测了下，要比自带的函数快差不多一倍，比xe汇编版也快很多

做了点优化，大概计算时间是Delphi 10.3.2自带函数的三分之一计算时间

function intToHexA(iValue: Cardinal; Digits: Integer): string;

const

hexChar: array[0..15] of char = '0123456789ABCDEF';

var

d: Integer;

i: Integer;

hexLen: Integer;

pc: PChar;

begin

if iValue = 0 then

begin

Result := StringOfChar('0', Digits);

end

else

begin

hexLen := 0;

for I := 0 to 7 do

begin

if ((iValue shr (i shl 2)) and $F) <> 0 then

hexLen := i + 1;

end;

if hexLen > Digits then

Digits := hexLen;

SetLength(Result, Digits);

pc := pchar(Result) + Digits - 1;

for i := 0 to hexLen - 1 do

begin

d := (iValue shr (i shl 2)) and $F;

pc^ := hexChar[d];

dec(pc);

end;

for I := 0 to (Digits - hexLen) - 1 do

begin

pc^ := '0';

dec(pc);

end;

来源：http://bbs.2ccc.com/topic.asp?topicid=575175

推荐分享