Delphi下获取网络数据乱码问题

根据不同字符集的网页的内容的获取。

// 函数说明: 获取当前页面的Html源代码
// @param     AURL    : 页面URL地址
// @param     ACharset: 页面字符集
// @param     AState  : 成功状态
//
// @returns   返回成功状态(True表示成功,False表示失败)
function GetHtmlContent(const AUrl, ACharset: string; var AState: Boolean): string;
var
  vStrStream: TStringStream;                        //用于接收数据的流
  vNetHandle, vURLHandle: HINTERNET;
  vBuffer: PChar;
  vReadSize: Cardinal;
  vCharsetInt: Integer;
begin
  try
    if UpperCase(ACharset) = 'UTF-8' then
      vCharsetInt := 65001//4
    else if UpperCase(ACharset) = 'GB2312' then
      vCharsetInt := 20936//2
    else if Pos(UpperCase(ACharset), 'MacRoman,MacCroatian') > 0 then
      vCharsetInt := 20127//1
    else if Pos(UpperCase(ACharset), 'GB-2312,ASCII, KOI8-R,KOI8-U, ISO-8859-1..ISO-8859-16,') > 0 then
      vCharsetInt := 20936//2
    else if Pos(UpperCase(ACharset), 'UTF8,EUC-KR') > 0 then
      vCharsetInt := 51932//3
    else if Pos(UpperCase(ACharset), 'EUC-JP,UTF-32LE,UTF-32BE') > 0 then
      vCharsetInt := 65001//4
    else if Pos(UpperCase(ACharset), 'UTF-7,UTF7,') > 0 then
      vCharsetInt := 65000 //6
    else
      vCharsetInt := 65001; // 4
    vStrStream := TStringStream.Create('', vCharsetInt);
    try
      GetMem(vBuffer, 65536);
      vReadSize := 0;
      vNetHandle := InternetOpen('Delphi', INTERNET_OPEN_TYPE_PRECONFIG, nil, nil, 0);
      vURLHandle := InternetOpenUrl(vNetHandle, PChar(AUrl), nil, 0, INTERNET_FLAG_RELOAD, 0);
      repeat
        InternetReadFile(vURLHandle, vBuffer, 1000, vReadSize);
        if vReadSize <> 0 then
          vStrStream.Write(vBuffer^, vReadSize);
      until vReadSize = 0;
      InternetCloseHandle(vURLHandle);
      InternetCloseHandle(vNetHandle);
      FreeMem(vBuffer);
      AState := True;
      Result := vStrStream.DataString;
    finally
      vStrStream.Free;
    end;
  except
    on e: Exception do
    begin
      AState := False;
      Result := '[Error]'+AUrl + '|' + e.Message;
    end;
  end;
end;

System.SysUtils.pas

...
function GetCPInfo(CodePage: Cardinal; var lpCPInfo: TCPInfo): Boolean;
begin
  Result := True;
  case CodePage of
    // Code page identifiers understood directly by iconv_open()
    154, 367, 437, 737, 775, 819, 850, 852,
    853, 855..858, 860..866, 869, 874, 922: lpCPInfo.MaxCharSize := 1;
    932, 936, 943, 949, 950: lpCPInfo.MaxCharSize := 2;
    1046, 1124, 1125, 1129, 1133, 1161, 1162, 1163, 1250..1258: lpCPInfo.MaxCharSize := 1;
    1361: lpCPInfo.MaxCharSize := 2;
    // Code page indentifiers translated to iconv_open() encoding names (by LocaleNameFromCodePage)
    10000, 10004..10007, 10010, 10017, 10021,
    10029, 10079, 10081, 10082: lpCPInfo.MaxCharSize := 1;        // MacRoman .. MacCroatian
    12000, 12001: lpCPInfo.MaxCharSize := 4;                      // UTF-32LE, UTF-32BE
    20127, 20866: lpCPInfo.MaxCharSize := 1;                      // ASCII, KOI8-R
    20932: lpCPInfo.MaxCharSize := 3;                             // EUC-JP
    20936: lpCPInfo.MaxCharSize := 2;                             // GB2312, EUC-KR
    21866, 28591..28601, 28603..28606: lpCPInfo.MaxCharSize := 1; // KOI8-U, ISO-8859-1..ISO-8859-16
    50221: lpCPInfo.MaxCharSize := 9;                             // ISO-2022-JP
    50225: lpCPInfo.MaxCharSize := 7;                             // ISO-2022-KR
    50227: lpCPInfo.MaxCharSize := 8;                             // ISO-2022-CN
    51932: lpCPInfo.MaxCharSize := 3;                             // EUC-JP
    51936, 51949: lpCPInfo.MaxCharSize := 2;                      // GB2312, EUC-KR
    51950, 52936, 54936: lpCPInfo.MaxCharSize := 4;               // EUC-TW, HZ-GB-2312, GB18030
    65000: lpCPInfo.MaxCharSize := 6;                             // UTF-7
    65001: lpCPInfo.MaxCharSize := 4;                             // UTF-8
  else
    Result := False;
  end;
end;
...