我需要一个用于Delphi的文件下载组件。你能帮助我吗?
使用高级别的URLDownloadToFile
函数:
uses UrlMon;
...
URLDownloadToFile(nil, 'http://www.rejbrand.se/', 'C:\Users\Andreas Rejbrand\Desktop\index.html', 0, nil);
或者,你可以非常容易地使用WinInet函数编写自己的下载器功能,类似于:
uses WinInet;
...
hInet := InternetOpen(PChar(UserAgent), INTERNET_OPEN_TYPE_PRECONFIG, nil, nil, 0);
try
hURL := InternetOpenUrl(hInet, PChar('http://' + Server + Resource), nil, 0, 0, 0);
try
repeat
InternetReadFile(hURL, @Buffer, SizeOf(Buffer), BufferLen);
...
在SO上有很多样例代码。请使用上面的搜索框。
我写了一个小示例。你可能想要在单独的线程中执行此代码,并让它每隔10KB左右回传一次,这样你就可以向用户提供一些进度条等信息。
function DownloadFile(const UserAgent, URL, FileName: string): boolean;
const
BUF_SIZE = 4096;
var
hInet, hURL: HINTERNET;
f: file;
buf: PByte;
amtc: cardinal;
amti: integer;
begin
result := false;
hInet := InternetOpen(PChar(UserAgent), INTERNET_OPEN_TYPE_PRECONFIG, nil, nil, 0);
try
hURL := InternetOpenUrl(hInet, PChar(URL), nil, 0, 0, 0);
try
GetMem(buf, BUF_SIZE);
try
FileMode := fmOpenWrite;
AssignFile(f, FileName);
try
Rewrite(f, 1);
repeat
InternetReadFile(hURL, buf, BUF_SIZE, amtc);
BlockWrite(f, buf^, amtc, amti);
until amtc = 0;
result := true;
finally
CloseFile(f);
end;
finally
FreeMem(buf);
end;
finally
InternetCloseHandle(hURL);
end;
finally
InternetCloseHandle(hInet);
end;
end;
你也可以使用Indy来制作:
procedure DownloadHTTP(const AUrl : string; DestStream: TStream);
begin
with TIdHTTP.Create(Application) do
try
try
Get(AUrl,DestStream);
except
On e : Exception do
MessageDlg(Format('Erreur : %s',[e.Message]), mtInformation, [mbOK], 0);
end;
finally
Free;
end;
end;