(Delphi ActiveX) Download a Zip from a URL and OpenBd. (No .zip file is created)

Demonstrates how to download a .zip from a URL, opens the Zip, and gets the contents of a file. No file is ever written.

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
http: TChilkatHttp;
bd: TChilkatBinData;
zip: TChilkatZip;
entry: TChilkatZipEntry;
lineEndingBehavior: Integer;
xmlStr: WideString;
sb: TChilkatStringBuilder;

begin
success := 0;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

http := TChilkatHttp.Create(Self);

bd := TChilkatBinData.Create(Self);

// This URL is valid and can be tested...
success := http.QuickGetBd('http://chilkatdownload.com/example_data/hamlet.zip',bd.ControlInterface);
if (http.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

zip := TChilkatZip.Create(Self);

// Open the zip from the bytes contained in bd.
success := zip.OpenBd(bd.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    Exit;
  end;

// Get the entry for the file we want..
entry := TChilkatZipEntry.Create(Self);
success := zip.EntryOf('hamlet.xml',entry.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    Exit;
  end;

// Convert all line endings to CRLF (if needed)
lineEndingBehavior := 2;
xmlStr := entry.UnzipToString(lineEndingBehavior,'utf-8');
if (entry.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(entry.LastErrorText);
    Exit;
  end;

// The XML in this case is about 274K, so let's just examine the last 20 lines...
sb := TChilkatStringBuilder.Create(Self);
sb.Append(xmlStr);

Memo1.Lines.Add(sb.LastNLines(20,1));
end;