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{============================
*函数名：Base64ToString*
*作者：*
*时间：2005.11.29 15.25 *
*说明：实现字符转换*
============================}
function TGetEmailInfo.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;
{============================
*函数名：StringToBase64*
*作者：*
*时间：2005.11.29 15.25 *
*说明：实现字符转换*
============================}
function TGetEmailInfo.StringToBase64(const Value: string): string;
var
c: Byte;
n, l: Integer;
Count: Integer;
DOut: array[0..3] of Byte;
Table : string;
begin
Table :=
'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
setlength(Result, ((Length(Value) + 2) div 3) * 4);
l := 1;
Count := 1;
while Count <= Length(Value) do
begin
c := Ord(Value[Count]);
Inc(Count);
DOut[0] := (c and $FC) shr 2;
DOut[1] := (c and $03) shl 4;
if Count <= Length(Value) then
begin
c := Ord(Value[Count]);
Inc(Count);
DOut[1] := DOut[1] + (c and $F0) shr 4;
DOut[2] := (c and $0F) shl 2;
if Count <= Length(Value) then
begin
c := Ord(Value[Count]);
Inc(Count);
DOut[2] := DOut[2] + (c and $C0) shr 6;
DOut[3] := (c and $3F);
end
else
begin
DOut[3] := $40;
end;
end
else
begin
DOut[2] := $40;
DOut[3] := $40;
end;
for n := 0 to 3 do
begin
Result[l] := Table[DOut[n] + 1];
Inc(l);
end;
end
end;
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