Downloading a file in Delphi

Question

A google search shows a few examples on how to download a file in Delphi but most are buggy and half of the time don\'t work in my experience.

I\'m looking for a si

Answer 1

Why not make use of indy. If you use the TIdHTTP its simple

procedure DownloadFile;    
var
  IdHTTP1: TIdHTTP;
  Stream: TMemoryStream;
  Url, FileName: String;
begin    
  Url := 'http://www.rejbrand.se';
  Filename := 'download.htm';

  IdHTTP1 := TIdHTTP.Create(Self);
  Stream := TMemoryStream.Create;
  try
    IdHTTP1.Get(Url, Stream);
    Stream.SaveToFile(FileName);
  finally
    Stream.Free;
    IdHTTP1.Free;
  end;
end;

You can even add a progress bar by using the OnWork and OnWorkBegin Events

procedure IdHTTPWorkBegin(ASender: TObject; AWorkMode: TWorkMode;AWorkCountMax: Int64);
begin
  ProgressBar.Max := AWorkCountMax;
  ProgressBar.Position := 0;
end;

procedure IdHTTPWork(ASender: TObject; AWorkMode: TWorkMode; AWorkCount: Int64);
begin
  ProgressBar.Position := AWorkCount;
end;

I'm not sure if these event fire in the context of the main thread, so any updates done to VCL components may have to be done using the tidnotify component to aviod threading issues. Maybe someone else can check that.