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Delphi的几种类型转换
unit Support;
interface
type dword=longword;
function WordToStr(Value: word): string;
function DwordToStr(Value: dword): string;
function StrToWord(Value: string): word;
function StrToDword(Value: string): dword;
procedure SetBit(var Str: string; BitNr: dword; Value: boolean);
function GetBit(Str: string; BitNr: dword): boolean;
function Pack(I: string):string;
function UnPack(I: string): string;
procedure FindBest(Main, Sub: string;var FoundLen, FoundPos: integer);
implementation
// DwordToStr() : Converts a DWORD to a 4 byte string
function DwordToStr(Value: dword): string;
var
ResultPtr: PChar;
begin
SetLength(Result, 4);
ResultPtr:=@Result[1];
asm
MOV EAX, [ResultPtr]
MOV EBX, Value
MOV [EAX], EBX end;
end;
// StrToDWord() : Converts a 4 byte string to a DWORD
function StrToDword(Value: string): dword;
var
ValuePtr: PChar;
begin
ValuePtr:=@Value[1];
asm
MOV EAX, [ValuePtr]
MOV EAX, [EAX]
MOV Result, EAX end;
end;
// WordToStr() : Converts a WORD to a 2 byte string
function WordToStr(Value: word): string;
var
ResultPtr: PChar;
begin
SetLength(Result, 2);
ResultPtr:=@Result[1];
asm
MOV EAX, [ResultPtr]
MOV BX, Value
MOV [EAX], BX end;
end;
// StrToWord() : Converts a 2 byte string to a WORD
function StrToWord(Value: string): word;
var
ValuePtr: PChar;
begin
ValuePtr:=@Value[1];
asm
MOV EAX, [ValuePtr]
MOV AX, [EAX]
MOV Result, AX end;
end;
function HexStrToStr(const S:string):string;
//16进制字符串转换成字符串
var
t:Integer;
ts:string;
M,Code:Integer;
begin
t:=1;
Result:='';
while t<=Length(S) do
begin //xlh 2006.10.21
while (t<=Length(S)) and (not (S[t] in ['0'..'9','A'..'F','a'..'f'])) do
inc(t);
if (t+1>Length(S))or(not (S[t+1] in ['0'..'9','A'..'F','a'..'f'])) then
ts:='$'+S[t]
else
ts:='$'+S[t]+S[t+1];
Val(ts,M,Code);
if Code=0 then
Result:=Result+Chr(M);
inc(t,2);
end;
end;
function StrToHexStr(const S:string):string;
//字符串转换成16进制字符串
var
I:Integer;
begin
for I:=1 to Length(S) do
begin
if I=1 then
Result:=IntToHex(Ord(S[1]),2)
else Result:=Result+' '+IntToHex(Ord(S[I]),2);
end;
end;
// SetBit() : Sets a single BIT in a string to true or false
procedure SetBit(var Str: string; BitNr: dword; Value: boolean);
var
CharNr: dword;
CharBit: byte;
Original, Mask: byte;
begin
CharNr:=(BitNr DIV 8)+1;
CharBit:=(BitNr MOD 8);
Original:=byte(Str[CharNr]);
Mask:=1 shl CharBit;
if Value=true then
Original:=(Original or Mask)
else
Original:=(Original and not Mask);
Str[CharNr]:=char(Original);
end;
// GetBit() : Returns the state of a single bit in a string
function GetBit(Str: string; BitNr: dword): boolean;
var
CharNr: dword;
CharBit: byte;
Original, Mask: byte;
begin
CharNr:=(BitNr DIV 8)+1;
CharBit:=(BitNr MOD 8);
Original:=byte(Str[CharNr]);
Mask:=1 shl CharBit;
if (Original and Mask)=Mask then
Result:=true
else
Result:=false;
end;
// Pack() : Compresses a string to a hopefully smaller string
function Pack(I: string):string;
var
Header: string;
Tag,T1,T2: string;
Buffer: string;
History: string;
FindStr: string;
P: integer;
FP,FL: integer;
begin
SetLength(Tag,(Length(I) DIV 8)+1); // Create TAG string
Header:=DwordToStr(Length(I)); // Create Header string (length of original)
// Pack the string
P:=1; while P<=Length(I) do begin
FindStr:=Copy(I,P,10);
FindBest(History,FindStr,FL,FP);
if FL>2 then begin // if match found in history and length>2
Buffer:=Buffer+WordToStr((FP SHL 3)+(FL-3));
History:=History+Copy(History,FP,FL);
T1:=Copy(I,P,FL);
T2:=Copy(History,FP,FL);
SetBit(Tag,P-1,true);
P:=P+(FL-1);
end else begin // if no match found in history
Buffer:=Buffer+I[P];
History:=History+I[P];
SetBit(Tag,P-1,false);
end;
if Length(History)>8100 then History:=Copy(History,1024,8100); INC(P);
end;
Result:=Header+Tag+Buffer;
end;
// UnPack() : DeCompresses a string compressed with Pack()
function UnPack(I: string): string;
var
Tag,T: string;
Buffer: string;
TmpWrd: string;
History: string;
P, OL: integer;
FP, FL: integer;
begin
// Split I in Tag and Buffer
OL:=StrToDword(I);
SetLength(Buffer, OL);
SetLength(Tag,(OL DIV 8)+1);
P:=5;
Tag:=Copy(I,P,Length(Tag));
P:=P+Length(Tag);
Buffer:=Copy(I,P,Length(Buffer));
Result:='';
// begin unpacking
P:=1; while Length(Result)<OL do begin
if GetBit(Tag, Length(Result))=true then begin // if is packed
TmpWrd:=Buffer[P]+Buffer[P+1];
FL:=(StrToWord(TmpWrd) and 7)+3;
FP:=(StrToWord(TmpWrd) shr 3) and 8191;
Result:=Result+Copy(History,FP,FL);
History:=History+Copy(History,FP,FL);
T:=Copy(History,FP,FL);
P:=P+1;
end else begin // if is not packed
Result:=Result+Buffer[P];
History:=History+Buffer[P];
end;
if Length(History)>8100 then History:=Copy(History,1024,8100); INC(P);
end;
end;
// FindBest() : Finds a substring in another string an returns position and
// the number of characters upto where they are equal
procedure FindBest(Main, Sub: string;var FoundLen, FoundPos: integer);
var
P,T,FL,MaxLen: integer;
begin
if Length(Sub)>Length(Main) then
MaxLen:=Length(Main)
else
MaxLen:=Length(Sub);
FoundLen:=0; FoundPos:=0;
for P:=1 to Length(Main)-MaxLen do begin
FL:=0;
for T:=1 to MaxLen do begin
if Main[P+T-1]=Sub[T] then FL:=T else Break;
end;
if FL>FoundLen then begin
FoundLen:=FL;
FoundPos:=P;
end;
end;
end;
end.
在做一些和硬件通讯的程序中，交换和读写的数据格式有时是 16 进制，比如说从 IC 卡 或 ID 卡获取到的数据，把他们转换成 10 进制可能更便于使用。
Delphi 中 16 进制数以 $ 为前缀，所以将 16 进制形式的字符串转换为整数即可：
function HexToDec(const AHexString: String): Integer;
begin
// 16 进制转换为 10 进制；
Result := StrToInt(’$’ + AHexString);
end;
//十六进制(S)-->>十进制(I) [重写:Jey]
function hextoint(s: string): Integer;
begin //$代表16进制
Result:=StrToInt('$'+s);
end;
//十进制转换为二进制字符串 [重写:Jey]
function inttoBin(i: integer): string;
begin
while i <>0 do
begin //i mod 2取模,再使用format格式化
result:=Format('%d'+result,[i mod 2]);
i:=i div 2
end
end;
//二进制(S)-->>十进制(D) [重写:Jey]
uses Math;
function hextoint(s: string): Double;
begin
while Length(s) <>0 do
begin //2^(长度-1)次方
if s[1]='1' then Result:=Result+power(2,Length(s)-1);
s:=Copy(s,2,Length(s));
end
end;
//十进制(I)-->>十六进制(S)
//D自带函数,Digits长度,一般设4.
function IntToHex(Value: Integer; Digits: Integer): string;
//数据(S)-->>二进制(S)
//任何数据都是以二进制形式存储的！ (转)
function conertde(s:string):string;
var
i:integer;
begin
for i:=1 to length(s) do
result:=result+inttohex(ord(s[i]),2);
end;
16进制字符转换为10进制 delphi
Function HexToDec(const Value :Integer ) : string;
var
s : string;
begin
s := '$' + IntToStr(Value);
Result := InToStr(StrToInt(s));
end;
（2）方法2
Funtion HexToDec(const Value :Integer) : string;
CONST HEX : ARRAY['A'..'F'] OF INTEGER =
(10,11,12,13,14,15);
VAR
str : String;
In : Integer;
i : integer;
BEGIN
Str := UpperCase(IntToStr(Value));
Int := 0;
FOR i := 1 TO Length(str) DO
IF str[i] ＜ 'A' THEN
Int := Int * 16 + ORD(str[i]) - 48
ELSE
Int := Int * 16 + HEX[str[i]];
Result := IntToStr(Int);
end;
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