delphi 通过WinInet HTTPS 下载文件

uses Winapi.WinInet

function Download(URL, User, Pass, FileName: string): Boolean;

const

  BufferSize = 1024;

var

  hSession, hURL: HInternet;

  Buffer: array[1..BufferSize] of Byte;

  BufferLen: DWORD;

  F: File;

begin

   Result := False;

   hSession := InternetOpen('', INTERNET_OPEN_TYPE_PRECONFIG, nil, nil, 0) ;

   // Establish the secure connection

   InternetConnect (

     hSession,

     PChar(FullURL),

     INTERNET_DEFAULT_HTTPS_PORT,

     PChar(User),

     PChar(Pass),

     INTERNET_SERVICE_HTTP,

     0,

     0

   );

  try

    hURL := InternetOpenURL(hSession, PChar(URL), nil, 0, 0, 0) ;

    try

      AssignFile(f, FileName);

      Rewrite(f,1);

      try

        repeat

          InternetReadFile(hURL, @Buffer, SizeOf(Buffer), BufferLen) ;

          BlockWrite(f, Buffer, BufferLen)

        until BufferLen = 0;

      finally

        CloseFile(f) ;

        Result := True;

      end;

    finally

      InternetCloseHandle(hURL)

    end

  finally

    InternetCloseHandle(hSession)

  end;

end;