111.pas

解决读邮件时如主题、正文等出现的中文乱码问题。

function tform4.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;