关于utf8解码的问题

[jxk]

我自己写了一个收邮件的程序，可是在收到以后，有如"=?utf-8?B?5p205pil6Zye?="的乱码，请问怎么才能把它转换成我可以看得懂的文字？最好给出代码！谢谢

[Billy_Chen28]

给你一个函数：
function utf8toansistring(utf8str:string; codepage:integer):ansistring;
var
i:integer;
buffer:widestring;
ch,c1,c2:byte;

begin
result:='';
i:=1;
while i<=length(utf8str) do begin
ch:=byte(utf8str[i]);
setlength(buffer,length(buffer)+1);
if (ch and $80)=0 then //1-byte
buffer[length(buffer)]:=widechar(ch)
else begin
if (ch and $e0) = $c0 then begin // 2-byte
inc(i);
c1 := byte(utf8str[i]);
buffer[length(buffer)]:=widechar((word(ch and $1f) shl 6) or (c1 and $3f));
end
else begin // 3-byte
inc(i);
c1 := byte(utf8str[i]);
inc(i);
c2 := byte(utf8str[i]);
buffer[length(buffer)]:=widechar(
(word(ch and $0f) shl 12) or
(word(c1 and $3f) shl 6) or
(c2 and $3f));
end;
end;
inc(i);
end; //while
i := widechartomultibyte(codepage,
wc_compositecheck or wc_discardns or wc_sepchars or wc_defaultchar,
@buffer[1], -1, nil, 0, nil, nil);
if i>1 then begin
setlength(result, i-1);
widechartomultibyte(codepage,
wc_compositecheck or wc_discardns or wc_sepchars or wc_defaultchar,
@buffer[1], -1, @result[1], i-1, nil, nil);
end;
end;

[jxk]

怎么用阿？

[liuxiaowei]

直接用以下函数就行了：
UnicodeToUtf8 function:
Converts a string of Unicode characters into a UTF-8 string.
UTF8Decode function:
Converts a UTF8 string to a Unicode string (WideString).
UTF8Encode function:
Converts a WideString value to a UTF8 string.
Utf8ToAnsi function:
Converts a UTF8 string to a string of Ansi characters.
Utf8ToUnicode function:
Converts a string of UTF-8 characters to a Unicode string.

[lifejoy]

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