类型：转载 责任编辑：asp.net 日期：2007/05/23
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使用TIdPOP3收邮件，如果是中文需要转码
中文邮件标题为：=?gb2312?B?xPrU2jUxam9iLmNvbcnPtqnUxLXEuaTX99PKvP4=?=
我使用IdDecoderMIME控件
IdDecoderMIME1.DecodeString(=?gb2312?B?xPrU2jUxam9iLmNvbcnPtqnUxLXEuaTX99PKvP4=?=);
上面这句话报错：Uneven size in DecodeToStream
请问是什么问题？我该如何解码呢？？？
网友回答：
俺帮你顶一下吧
使用下面的函数进行解码：
function Tfemail.Base64ToString(const Value: string): string;
var
x, y, n, l: Integer;
d: array[0..3] of Byte;
Table : string;
begin
Table :=
#$40 +#$40 +#$40 +#$40 +#$40 +#$40 +#$40 +#$40 +#$40 +#$40 +#$3E +#$40
+#$40 +#$40 +#$3F +#$34 +#$35 +#$36 +#$37 +#$38 +#$39 +#$3A +#$3B +#$3C
+#$3D +#$40 +#$40 +#$40 +#$40 +#$40 +#$40 +#$40 +#$00 +#$01 +#$02 +#$03
+#$04 +#$05 +#$06 +#$07 +#$08 +#$09 +#$0A +#$0B +#$0C +#$0D +#$0E +#$0F
+#$10 +#$11 +#$12 +#$13 +#$14 +#$15 +#$16 +#$17 +#$18 +#$19 +#$40 +#$40
+#$40 +#$40 +#$40 +#$40 +#$1A +#$1B +#$1C +#$1D +#$1E +#$1F +#$20 +#$21
+#$22 +#$23 +#$24 +#$25 +#$26 +#$27 +#$28 +#$29 +#$2A +#$2B +#$2C +#$2D
+#$2E +#$2F +#$30 +#$31 +#$32 +#$33 +#$40 +#$40 +#$40 +#$40 +#$40 +#$40;
SetLength(Result, Length(Value));
x := 1;
l := 1;
while x < Length(Value) do
begin
for n := 0 to 3 do
begin
if x > Length(Value) then
d[n] := 64
else
begin
y := Ord(Value[x]);
if (y < 33) or (y > 127) then
d[n] := 64
else
d[n] := Ord(Table[y - 32]);
end;
Inc(x);
end;
Result[l] := Char((D[0] and $3F) shl 2 + (D[1] and $30) shr 4);
Inc(l);
if d[2] <> 64 then
begin
Result[l] := Char((D[1] and $0F) shl 4 + (D[2] and $3C) shr 2);
Inc(l);
if d[3] <> 64 then
begin
Result[l] := Char((D[2] and $03) shl 6 + (D[3] and $3F));
Inc(l);
end;
end;
end;
Dec(l);
SetLength(Result, l);
end;
同意楼上
其实邮件的标题编码无非是同样的编码，只不过，还需要经过一下处理才能进行解码的。
Function QuotedPrintableEncode(mSource: String): String;
Var
I, J: Integer;
Begin
Result := ;
J := 0;
For I := 1 To Length(mSource) Do Begin
If mSource[I] In [#32..#127, #13, #10] - [=] Then Begin
Result := Result + mSource[I];
Inc(J);
End Else Begin
Result := Result + = + IntToHex(Ord(mSource[I]), 2);
Inc(J, 3);
End;
If mSource[I] In [#13, #10] Then J := 0;
If J >= 70 Then Begin
Result := Result + #13#10;
J := 0;
End;
End;
End; { QuotedPrintableEncode }
Function QuotedPrintableDecode(mCode: String): String;
Var
I, J, L: Integer;
Begin
Result := ;
J := 0;
mCode := AdjustLineBreaks(mCode);
L := Length(mCode);
I := 1;
While I <= L Do Begin
If mCode[I] = = Then Begin
Result := Result + Chr(StrToIntDef($ + Copy(mCode, I + 1, 2), 0));
Inc(J, 3);
Inc(I, 3);
End Else If mCode[I] In [#13, #10] Then Begin
If J < 70 Then Result := Result + mCode[I];
If mCode[I] = #10 Then J := 0;
Inc(I);
End Else Begin
Result := Result + mCode[I];
Inc(J);
Inc(I);
End;
End;
End; { QuotedPrintableDecode }
Function Base64Encode(mSource: String; mAddLine: Boolean = True): String;
Var
I, J: Integer;
S: String;
Begin
Result := ;
J := 0;
For I := 0 To Length(mSource) Div 3 - 1 Do Begin
S := Copy(mSource, I * 3 + 1, 3);
Result := Result + cBase64[Ord(S[1]) Shr 2 + 1];
Result := Result + cBase64[((Ord(S[1]) And $03) Shl 4) + (Ord(S[2]) Shr 4) + 1];
Result := Result + cBase64[((Ord(S[2]) And $0F) Shl 2) + (Ord(S[3]) Shr 6) + 1];
Result := Result + cBase64[Ord(S[3]) And $3F + 1];
If mAddLine Then Begin
Inc(J, 4);
If J >= 76 Then Begin
Result := Result + #13#10;
J := 0;
End;
End;
End;
I := Length(mSource) Div 3;
S := Copy(mSource, I * 3 + 1, 3);
Case Length(S) Of
1: Begin
Result := Result + cBase64[Ord(S[1]) Shr 2 + 1];
Result := Result + cBase64[(Ord(S[1]) And $03) Shl 4 + 1];
Result := Result + cBase64[65];
Result := Result + cBase64[65];
End;
2: Begin
Result := Result + cBase64[Ord(S[1]) Shr 2 + 1];
Result := Result + cBase64[((Ord(S[1]) And $03) Shl 4) + (Ord(S[2]) Shr 4) + 1];
Result := Result + cBase64[(Ord(S[2]) And $0F) Shl 2 + 1];
Result := Result + cBase64[65];
End;
End;
End; { Base64Encode }
Function Base64Decode(mCode: String): String;
Var
I, L: Integer;
S: String;
Begin
Result := ;
L := Length(mCode);
I := 1;
While I <= L Do Begin
If Pos(mCode[I], cBase64) > 0 Then Begin
S := Copy(mCode, I, 4);
If (Length(S) = 4) Then Begin
Result := Result + Chr((Pos(S[1], cBase64) - 1) Shl 2 +
(Pos(S[2], cBase64) - 1) Shr 4);
If S[3] <> cBase64[65] Then Begin
Result := Result + Chr(((Pos(S[2], cBase64) - 1) And $0F) Shl 4 +
(Pos(S[3], cBase64) - 1) Shr 2);
If S[4] <> cBase64[65] Then
Result := Result + Chr(((Pos(S[3], cBase64) - 1) And $03) Shl 6 +
(Pos(S[4], cBase64) - 1));
End;
End;
Inc(I, 4);
End Else Inc(I);
End;
End; { Base64Decode }
Function GetTitle(Const Value: String): String;
Var
iPos: integer;
Begin
Result := Value;
If Copy(Value, 1, 2) <> =? Then
Begin
Result := Value;
exit;
End;
//?B?前面的都要去掉
iPos := Pos(?B?, Value);
If iPos = 0 Then
Begin
iPos := Pos(?Q?, Value);
If iPos = 0 Then
Begin
Result := Value;
exit;
End;
Inc(iPos, 3);
//最后的?=也要去掉
Result := Copy(Value, iPos, Length(Value) - iPos - 1);
Result := QuotedPrintableDecode(Result);
End
Else
Begin
Inc(iPos, 3);
//最后的?=也要去掉
Result := Copy(Value, iPos, Length(Value) - iPos - 1);
Result := Base64Decode(Result);
End;
End;
示例：
ShowMessage(GetTitle(=?gb2312?B?xPrU2jUxam9iLmNvbcnPtqnUxLXEuaTX99PKvP4=?=));