Using the Chilkat ActiveX in Delphi

import the Chilkat type library once, then use Chilkat classes like any other Delphi component

Windows · Delphi 7 through current RAD Studio · Win32 and Win64 targets · Chilkat ActiveX v11

Delphi has built-in support for COM. You import the Chilkat ActiveX type library once, and Delphi generates a Pascal unit, Chilkat_TLB.pas, with a wrapper class for every Chilkat class: TChilkatHttp, TChilkatJsonObject, TChilkatCrypt2, and so on. Your code then creates and calls those classes directly, with code completion and compile-time checking.

ActiveX or the Chilkat Delphi DLL?

Chilkat offers two products for Delphi. Both contain the same Chilkat functionality.

On this page: Install Import Unlock First program Passing objects Console apps & threads Tips Deploying Troubleshooting

Setup

Examples

Unlock Chilkat once at startup

Call UnlockBundle once when your program starts; the unlock applies to every Chilkat object in the process until it exits. During the 30-day trial any string works; after purchase, use your license code.

uses
  ..., Chilkat_TLB;

procedure TForm1.FormCreate(Sender: TObject);
var
  glob: TChilkatGlobal;
begin
  glob := TChilkatGlobal.Create(Self);
  try
    if glob.UnlockBundle('Anything for 30-day trial') <> 1 then
      ShowMessage(glob.LastErrorText);
  finally
    glob.Free;
  end;
end;

Your first program: fetch a URL

Put a TButton and a TMemo on the form and use this as the button's OnClick handler:

procedure TForm1.Button1Click(Sender: TObject);
var
  http: TChilkatHttp;
  s: WideString;
begin
  http := TChilkatHttp.Create(Self);
  try
    s := http.QuickGetStr('https://www.chilkatsoft.com/helloworld.txt');
    if http.LastMethodSuccess <> 1 then
    begin
      Memo1.Lines.Add(http.LastErrorText);
      Exit;
    end;
    Memo1.Lines.Add(s);
  finally
    http.Free;
  end;
end;

Run it and click the button: the memo shows Hello World!.

Passing one Chilkat object to another

Many Chilkat methods take another Chilkat object as an argument, such as an HttpResponse to receive a response. The generated method expects the object's COM interface, so pass the wrapper's ControlInterface property:

procedure TForm1.Button2Click(Sender: TObject);
var
  http: TChilkatHttp;
  resp: TChilkatHttpResponse;
begin
  http := TChilkatHttp.Create(Self);
  resp := TChilkatHttpResponse.Create(Self);
  try
    // POST a JSON body; the server's reply is written into resp.
    if http.HttpStr('POST', 'https://httpbin.org/post', '{"name":"value"}',
                    'utf-8', 'application/json', resp.ControlInterface) <> 1 then
    begin
      Memo1.Lines.Add(http.LastErrorText);
      Exit;
    end;
    Memo1.Lines.Add('Status: ' + IntToStr(resp.StatusCode));
    Memo1.Lines.Add(resp.BodyStr);
  finally
    resp.Free;
    http.Free;
  end;
end;

Methods that return a new Chilkat object return its interface (for example IChilkatJsonObject), which you can use directly; Delphi releases it automatically.

Console applications, services, and threads

The TChilkat… wrapper classes are designed for VCL forms. In console programs, Windows services, and background threads, use the COM interfaces instead: create objects with CreateComObject and the CLASS_… constants from Chilkat_TLB. Interfaces are reference-counted, so there is nothing to free, and objects are passed to methods directly (no ControlInterface).

Every thread that uses COM must call CoInitialize first and CoUninitialize when it's done. VCL form applications do this for the main thread automatically; console programs and your own threads must do it themselves:

program ChilkatConsole;

{$APPTYPE CONSOLE}

uses
  System.SysUtils, Winapi.ActiveX, System.Win.ComObj, Chilkat_TLB;

var
  glob: IChilkatGlobal;
  http: IChilkatHttp;
  s: WideString;
begin
  CoInitialize(nil);
  try
    glob := CreateComObject(CLASS_ChilkatGlobal) as IChilkatGlobal;
    if glob.UnlockBundle('Anything for 30-day trial') <> 1 then
    begin
      Writeln(glob.LastErrorText);
      Exit;
    end;

    http := CreateComObject(CLASS_ChilkatHttp) as IChilkatHttp;
    s := http.QuickGetStr('https://www.chilkatsoft.com/helloworld.txt');
    if http.LastMethodSuccess <> 1 then
      Writeln(http.LastErrorText)
    else
      Writeln(s);
  finally
    // Release all Chilkat interfaces before CoUninitialize.
    http := nil;
    glob := nil;
    CoUninitialize;
  end;
end.

In Delphi versions before XE2, the units are named ActiveX and ComObj instead of Winapi.ActiveX and System.Win.ComObj.

Things to know

Topic	What to do
Success values	Chilkat ActiveX methods that report success, and properties such as LastMethodSuccess, are Integer: 1 for success and 0 for failure. Compare with <> 1 or = 0; don't treat them as Boolean.
Errors	Chilkat doesn't raise exceptions for ordinary failures. Check the return value (or LastMethodSuccess for methods that return a string or object) and read LastErrorText, which explains exactly what went wrong. COM-level problems, such as an unregistered DLL, raise EOleSysError.
Strings	Chilkat strings are WideString (Unicode). In Delphi 2009 and later they convert to and from string automatically. In Delphi 7–2007, string is ANSI, so keep text in WideString variables to avoid losing non-ANSI characters.
Object lifetime	Wrapper objects created with Create(Self) are freed with the form if you don't free them yourself; try…finally Free releases them as soon as you're done. Interface variables are released automatically when they go out of scope or are set to nil.
Events	The wrapper classes expose Chilkat's progress events (AbortCheck, PercentDone, ProgressInfo, …) as On… event properties. The exact handler signatures are declared in Chilkat_TLB.pas; if you installed the classes in a package, the Object Inspector creates the handlers for you.
Long operations	A Chilkat call blocks the thread it runs on, so a long download in a button handler freezes the form. Set timeouts such as ConnectTimeout and ReadTimeout, or run the work in a background thread using the interface style shown above.
Late binding	CreateOleObject('Chilkat.Http') returns an OleVariant and needs no imported unit, but gives up code completion and compile-time checking. It's useful for quick scripts; for applications, use the imported unit.
Chilkat v9.5 code	v11 imports as Chilkat_TLB and uses ProgIDs such as Chilkat.Http. Code written for v9.5 used Chilkat_v9_5_0_TLB and Chilkat_9_5_0.Http-style ProgIDs; change the uses clause after importing v11. Both versions can be installed side by side; see Chilkat ActiveX v11 and v9.5 on the same computer.

Deploying your application

Your EXE does not contain Chilkat. Every computer that runs it needs the Chilkat ActiveX DLL installed and registered, with the same bitness as the EXE: 32-bit for a Win32 build, 64-bit for a Win64 build.

• The simplest option is to run the matching Chilkat per-machine MSI as part of your setup.
• If your own installer copies the DLL, have it register the DLL. Most installer tools can register COM DLLs (Inno Setup, for example, has a regserver flag), or run regsvr32 <path-to-Chilkat-DLL> from an elevated command prompt.
• Install the DLL on a local drive of the target computer, not a network share.

Troubleshooting

Symptom	Cause and fix
Chilkat ActiveX isn't listed in the Import Component wizard	The Chilkat ActiveX isn't registered for the IDE you're using. The usual 32-bit IDE's wizard reads only the 32-bit registry, even if the 64-bit ActiveX is installed, so install the 32-bit version (and the 64-bit version too if you use RAD Studio's 64-bit IDE). Alternatively, run Embarcadero's tlibimp.exe command-line importer on the Chilkat DLL.
EOleSysError: Class not registered	The Chilkat ActiveX with your program's bitness isn't registered on this computer. A Win64 program needs the 64-bit ActiveX even if the 32-bit one is installed. Install or register the matching DLL.
EOleSysError: CoInitialize has not been called	A console program, service, or thread used COM without initializing it. Call CoInitialize(nil) at the start of that thread and CoUninitialize at the end (see Console applications).
EOleSysError: Invalid class string	A late-bound CreateOleObject call used a ProgID that isn't registered: a typo, or a v9.5 ProgID (Chilkat_9_5_0.…) on a computer with only v11 installed.
F1026 File not found: 'Chilkat_TLB.dcu'	The generated unit isn't in the project or on the search path. Add Chilkat_TLB.pas to the project, or add its folder under Project » Options » Delphi Compiler » Search path.
E2003 Undeclared identifier: 'TChilkatHttp'	The unit was imported without component wrappers, so it contains only the interfaces. Re-import with Generate Component Wrappers checked, or use the interface style (IChilkatHttp with CreateComObject).
E2003 Undeclared identifier (a Chilkat method or property)	The name is misspelled, or Chilkat_TLB.pas was generated from an older Chilkat version. Re-import after upgrading.
A Chilkat method returns 0 or an empty string	The operation itself failed (a network error, a bad password, an invalid file path, and so on). Show LastErrorText; it names the cause.

Next Steps

• 📖 Chilkat Delphi ActiveX Reference Documentation — every class, method, and property with its Delphi signature
• 💻 Chilkat Delphi ActiveX examples — ready-to-run code for HTTP, email, SFTP, JSON, encryption, and more
• 🏛️ Chilkat Delphi DLL — the non-COM alternative
• 📦 Chilkat ActiveX downloads (MSI installers and ZIP files)
• ✉ Contact Chilkat support

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