读取、下载一个网络文件

uses Wininet;

function GetInetFile
(const fileURL, FileName: String): boolean;
const BufferSize = 1024;
var
  hSession, hURL: HInternet;
  Buffer: array[1..BufferSize] of Byte;
  BufferLen: DWORD;
  f: File;
  sAppName: string;
begin
 Result:=False;
 sAppName := ExtractFileName(Application.ExeName);
 hSession := InternetOpen(PChar(sAppName),
                INTERNET_OPEN_TYPE_PRECONFIG,
               nil, nil, 0);
 try
  hURL := InternetOpenURL(hSession,
            PChar(fileURL),
            nil,0,0,0);
  try
   AssignFile(f, FileName);
   Rewrite(f,1);
   repeat
    InternetReadFile(hURL, @Buffer,
                     SizeOf(Buffer), BufferLen);
    BlockWrite(f, Buffer, BufferLen)
   until BufferLen = 0;
   CloseFile(f);
   Result:=True;
  finally
   InternetCloseHandle(hURL)
  end
 finally
  InternetCloseHandle(hSession)
 end
end;

var FileOnNet, LocalFileName: string
begin
 FileOnNet:=
  'http://delphi.about.com/library/forminbpl.zip';
 LocalFileName:='File Downloaded From the Net.zip'

 if GetInetFile(FileOnNet,LocalFileName)=True then
  ShowMessage('Download successful')
 else
  ShowMessage('Error in file download')

end;