delphi XE7 HttpEncode 編碼問題，xe7httpencode
近期在做網址編碼相關的工作，發現在用 XE5 編譯的時候，一切正常，拿 到 XE7下 就 結果錯誤了。百度了下，谷歌 了下，有人提出，但是，我沒有找到答案，也許都沒有碰到這個問題，也許都己經自己默默的解決了，在此 小記一下，方便後人，也方便自己 查尋。
例子 ： 原字符 "過年"
httpencode('過年') 結果 ：
XE5為 %B9%FD%C4%EA
XE7 調用 相當函數結果 %E8%BF%87%E5%B9%B4
百思不得其解啊，折騰了很長時間，後來終於想到是不是 此函數 官方更新修改了，（沒辦法，人比較笨）
於是查看源碼：
XE5的 web.httpapp 中（分string 和 ansistring， 我用ansistring 版本得到 期望的結果）：
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1 function HTTPEncode(const AStr: string): string;
2 // The NoConversion set contains characters as specificed in RFC 1738 and
3 // should not be modified unless the standard changes.
4 const
5 NoConversion = [Ord('A')..Ord('Z'), Ord('a')..Ord('z'), Ord('*'), Ord('@'),
6 Ord('.'), Ord('_'), Ord('-'), Ord('0')..Ord('9'), Ord('$'),
7 Ord('!'), Ord(''''), Ord('('), Ord(')')];
8 var
9 Sp, Rp: PChar;
10 begin
11 SetLength(Result, Length(AStr) * 3);
12 Sp := PChar(AStr);
13 Rp := PChar(Result);
14 while Sp^ <> #0 do
15 begin
16 if Ord(Sp^) in NoConversion then
17 Rp^ := Sp^
18 else
19 if Sp^ = ' ' then
20 Rp^ := '+'
21 else
22 begin
23 FormatBuf(Rp, 3, string('%%%.2x'), 6, [Ord(Sp^)]);
24 Inc(Rp,2);
25 end;
26 Inc(Rp);
27 Inc(Sp);
28 end;
29 SetLength(Result, Rp - PChar(Result));
30 end;
31
32 function HTTPDecode(const AStr: string): string;
33 var
34 Sp, Rp, Cp: PChar;
35 S: string;
36 begin
37 SetLength(Result, Length(AStr));
38 Sp := PChar(AStr);
39 Rp := PChar(Result);
40 Cp := Sp;
41 try
42 while Sp^ <> #0 do
43 begin
44 case Sp^ of
45 '+': Rp^ := ' ';
46 '%': begin
47 // Look for an escaped % (%%) or %<hex> encoded character
48 Inc(Sp);
49 if Sp^ = '%' then
50 Rp^ := '%'
51 else
52 begin
53 Cp := Sp;
54 Inc(Sp);
55 if (Cp^ <> #0) and (Sp^ <> #0) then
56 begin
57 S := Char('$') + Cp^ + Sp^;
58 Rp^ := Char(StrToInt(string(S)));
59 end
60 else
61 raise EWebBrokerException.CreateFmt(sErrorDecodingURLText, [Cp - PChar(AStr)]);
62 end;
63 end;
64 else
65 Rp^ := Sp^;
66 end;
67 Inc(Rp);
68 Inc(Sp);
69 end;
70 except
71 on E:EConvertError do
72 raise EConvertError.CreateFmt(sInvalidURLEncodedChar,
73 [Char('%') + Cp^ + Sp^, Cp - PChar(AStr)])
74 end;
75 SetLength(Result, Rp - PChar(Result));
76 end;
77
78 function HTTPEncode(const AStr: AnsiString): AnsiString;
79 // The NoConversion set contains characters as specificed in RFC 1738 and
80 // should not be modified unless the standard changes.
81 const
82 NoConversion = ['A'..'Z','a'..'z','*','@','.','_','-',
83 '0'..'9','$','!','''','(',')'];
84 var
85 Sp, Rp: PAnsiChar;
86 begin
87 SetLength(Result, Length(AStr) * 3);
88 Sp := PAnsiChar(AStr);
89 Rp := PAnsiChar(Result);
90 while Sp^ <> #0 do
91 begin
92 if Sp^ in NoConversion then
93 Rp^ := Sp^
94 else
95 if Sp^ = ' ' then
96 Rp^ := '+'
97 else
98 begin
99 System.AnsiStrings.FormatBuf(Rp^, 3, AnsiString('%%%.2x'), 6, [Ord(Sp^)]);
100 Inc(Rp,2);
101 end;
102 Inc(Rp);
103 Inc(Sp);
104 end;
105 SetLength(Result, Rp - PAnsiChar(Result));
106 end;
View Code
在XE7中
web.httpapp:
function HTTPEncode(const AStr: string): string;
begin
Result := TNetEncoding.URL.Encode(AStr);
end;
查看 system.netencoding
找到
function TNetEncoding.DoEncode(const Input: array of Byte): TBytes;
begin
Result := TEncoding.UTF8.GetBytes(DoEncode(TEncoding.UTF8.GetString(@Input[0])));
end;
查看類定義：
TURLEncoding = class(TNetEncoding)
protected
function DoDecode(const Input: string): string; overload; override;
function DoEncode(const Input: string): string; overload; override;
end;
查看函數代碼：
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function TURLEncoding.DoEncode(const Input: string): string;
// The NoConversion set contains characters as specificed in RFC 1738 and
// should not be modified unless the standard changes.
const
NoConversion = [Ord('A')..Ord('Z'), Ord('a')..Ord('z'), Ord('*'), Ord('@'),
Ord('.'), Ord('_'), Ord('-'), Ord('0')..Ord('9'), Ord('$'),
Ord('!'), Ord(''''), Ord('('), Ord(')')];
procedure AppendByte(B: Byte; var Buffer: PChar);
const
Hex = '0123456789ABCDEF';
begin
Buffer[0] := '%';
Buffer[1] := Hex[B shr 4 + Low(string)];
Buffer[2] := Hex[B and $F + Low(string)];
Inc(Buffer, 3);
end;
var
Sp, Rp: PChar;
MultibyteChar: TBytes;
I, ByteCount: Integer;
begin
// Characters that require more than 1 byte are translated as "percent-encoded byte"
// which will be encoded with 3 chars per byte -> %XX
// Example: ?character
// Multibyte representation: C391 (2 bytes)
// URL encode representation: %C3%91
//
// So the worst case is 4 bytes(max) per Char, and 3 characters to represent each byte
SetLength(Result, Length(Input) * 4 * 3);
Sp := PChar(Input);
Rp := PChar(Result);
SetLength(MultibyteChar, 4);
while Sp^ <> #0 do
begin
if Ord(Sp^) in NoConversion then
begin
Rp^ := Sp^;
Inc(Rp)
end
else if Sp^ = ' ' then
begin
Rp^ := '+';
Inc(Rp)
end
else
begin
if (Ord(Sp^) < 128) then
// Single byte char
AppendByte(Ord(Sp^), Rp)
else
begin
// Multi byte char
ByteCount := TEncoding.UTF8.GetBytes([Sp^], 0, 1, MultibyteChar, 0);
for I := 0 to ByteCount - 1 do
AppendByte(MultibyteChar[I], Rp);
end
end;
Inc(Sp);
end;
SetLength(Result, Rp - PChar(Result));
end;
View Code
似乎有點不同。
目前是我自己建立一個函數 ，復制XE5版本的 代碼 放在XE7裡面調用，得到希望的結果的。
代碼：
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function MyHTTPEncode(const AStr: AnsiString): AnsiString;
// The NoConversion set contains characters as specificed in RFC 1738 and
// should not be modified unless the standard changes.
const
NoConversion = ['A'..'Z','a'..'z','*','@','.','_','-',
'0'..'9','$','!','''','(',')'];
var
Sp, Rp: PAnsiChar;
begin
SetLength(Result, Length(AStr) * 3);
Sp := PAnsiChar(AStr);
Rp := PAnsiChar(Result);
while Sp^ <> #0 do
begin
if Sp^ in NoConversion then
Rp^ := Sp^
else
if Sp^ = ' ' then
Rp^ := '+'
else
begin
System.AnsiStrings.FormatBuf(Rp^, 3, AnsiString('%%%.2x'), 6, [Ord(Sp^)]);
Inc(Rp,2);
end;
Inc(Rp);
Inc(Sp);
end;
SetLength(Result, Rp - PAnsiChar(Result));
end;
View Code
