TChilkatDkim Delphi ActiveX Reference Documentation

TChilkatDkim

Current Version: 9.5.0.73

DomainKeys API for creating and verifying DKIM-Signature and DomainKey-Signature MIME (email) header fields. This API is included with the "Chilkat MIME" license. ("Chilkat MIME" may be referred to as "Chilkat S/MIME" on some chilkatsoft.com web pages. They are the same product.)

Importing the Chilkat ActiveX into Delphi

Important: When upgrading to a new version of Chilkat, make sure to re-imported ActiveX DLL into Delphi to regenerate the files described below.

Two things are required to use an ActiveX in Delphi:

  1. The ActiveX DLL needs to be registered via regsvr32 on the system where the Delphi application runs. See How To Register ActiveX DLLs for detailed information.
  2. See also: ActiveX Registration Tutorial
  3. The ActiveX component needs to be "imported". Use the Delphi Import Component Wizard to import the Chilkat type library. This creates the following files: Chilkat_v9_5_0_TLB.pas and Chilkat_v9_5_0_TLB.dcr. The Chilkat_v9_5_0_TLB.pas should be added to your project.

To import the Chilkat type library, do the following:

  1. In the Delphi RAD Studio, select the menu item "Component" --> "Import a Type Library".
  2. Find "Chilkat ActiveX v9.5.0" in the list and select it. This will only appear in the list if the ChilkatAx-9.5.0-win32.dll (or ChilkatAx-9.5.0-x64.dll) has been registered w/ regsvr32.
  3. Check the "Generate Component Wrappers" checkbox.
  4. Select a directory where the unit files (.pas and .dcr) should be generated.
  5. Select "Create Unit" and then "Finish".
  6. Add the .pas to your Delphi project.

To use a Chilkat ActiveX object in your Delphi code, add "Chilkat_v9_5_0_TLB" to the "uses" statement. For example:

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_v9_5_0_TLB;

Object Creation

var
obj: TChilkatDkim;
...
begin
obj := TChilkatDkim.Create(Self);
...
// When finished, free the object instance.
obj.Free();

Properties

AbortCurrent
property AbortCurrent: Integer
Introduced in version 9.5.0.58

When set to 1, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to 0 when the next method is called. When the abort occurs, this property is reset to 0. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

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DebugLogFilePath
property DebugLogFilePath: WideString

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

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DkimAlg
property DkimAlg: WideString

The signing algorithm to be used in creating the DKIM-Signature. Possible values are "rsa-sha256" and "rsa-sha1". The default value is "rsa-sha256".

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DkimBodyLengthCount
property DkimBodyLengthCount: Integer

Optional body length count to set a maximum number of body bytes to be hashed when creating the DKIM-Signature field. The default value is 0, indicating that the entire body should be hashed.

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DkimCanon
property DkimCanon: WideString

Canonicalization algorithm to be used for both header and body when creating the DKIM-Signature. Possible values are "simple" and "relaxed". The default value is "relaxed".

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DkimDomain
property DkimDomain: WideString

The domain name of the signing domain when creating the DKIM-Signature.

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DkimHeaders
property DkimHeaders: WideString

A colon-separated list of header field names that identify headers presented to the signing algorithm when creating the DKIM-Signature. The default value is: "mime-version:date:message-id:subject:from:to:content-type".

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DkimSelector
property DkimSelector: WideString

The selector to be used to form the DNS query for the public key. This property applies to creating a DKIM-Signature. For example, if the selector is "reykjavik" and the domain is "example-code.com", then the DNS query would be for "reykjavik._domainkey.example-code.com".

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DomainKeyAlg
property DomainKeyAlg: WideString

The signing algorithm to be used in creating the DomainKey-Signature. The only possible value is "rsa-sha1". The default value is "rsa-sha1".

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DomainKeyCanon
property DomainKeyCanon: WideString

Canonicalization algorithm to be used for when creating the DomainKey-Signature. Possible values are "simple" and "nofws". The default value is "nofws".

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DomainKeyDomain
property DomainKeyDomain: WideString

The domain name of the signing domain when creating the DomainKey-Signature.

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DomainKeyHeaders
property DomainKeyHeaders: WideString

A colon-separated list of header field names that identify headers presented to the signing algorithm when creating the DomainKey-Signature. The default value is: "mime-version:date:message-id:subject:from:to:content-type".

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DomainKeySelector
property DomainKeySelector: WideString

The selector to be used to form the DNS query for the public key. This property applies to creating a DomainKey-Signature. For example, if the selector is "reykjavik" and the domain is "example-code.com", then the DNS query would be for "reykjavik._domainkey.example-code.com".

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HeartbeatMs
property HeartbeatMs: Integer

The number of milliseconds between each AbortCheck event callback. The AbortCheck callback allows an application to abort any method call prior to completion. If HeartbeatMs is 0 (the default), no AbortCheck event callbacks will fire.

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LastBinaryResult
property LastBinaryResult: OleVariant readonly
Introduced in version 9.5.0.52

The binary data returned by the last (binary data returning) method called. Only available if Chilkat.Global.KeepBinaryResult is set to 1. This provides a means for obtaining large varbinary results in the SQL Server environment (where limitations exist in getting large amounts of data returned by method calls, but where temp tables can be used for binary properties).

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LastErrorHtml
property LastErrorHtml: WideString readonly

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
property LastErrorText: WideString readonly

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
property LastErrorXml: WideString readonly

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastMethodSuccess
property LastMethodSuccess: Integer
Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of 1 indicates success, a value of 0 indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = 1 and failure = 0.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to 1. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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LastStringResult
property LastStringResult: WideString readonly
Introduced in version 9.5.0.52

The string return value of the last (string returning) method called. Only available if Chilkat.Global.KeepStringResult is set to 1. This provides a means for obtaining large string results in the SQL Server environment (where limitations exist in getting long strings returned by method calls, but where temp tables can be used for string properties).

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LastStringResultLen
property LastStringResultLen: Integer readonly
Introduced in version 9.5.0.53

The length, in characters, of the string contained in the LastStringResult property.

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VerboseLogging
property VerboseLogging: Integer

If set to 1, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is 0. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
property Version: WideString readonly

Version of the component/library, such as "9.5.0.63"

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Methods

AddDkimSignature
function AddDkimSignature(mimeIn: OleVariant): OleVariant;
This method is deprecated. It will be removed in a future version.

Constructs and prepends a DKIM-Signature header to the MIME. Prior to calling this method, your program must set both the DkimDomain and DkimSelector properties, and it must load a private key by calling LoadDkimPk or LoadDkimPkFile.

Note: This method is deprecated. Use the DkimSign method instead.

Returns a zero-length byte array (as an OleVariant) on failure.
An empty array will have a VarArrayHighBound of -1 meaning 0 elements.

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AddDomainKeySignature
function AddDomainKeySignature(mimeIn: OleVariant): OleVariant;
This method is deprecated. It will be removed in a future version.

Constructs and prepends a DomainKey-Signature header to the MIME. Prior to calling this method, your program must set both the DomainKeyDomain and DomainKeySelector properties, and it must load a private key by calling LoadDomainKeyPk or LoadDomainKeyPkFile.

Note: This method is deprecated. Use the DomainKeySign method instead.

Returns a zero-length byte array (as an OleVariant) on failure.
An empty array will have a VarArrayHighBound of -1 meaning 0 elements.

More Information and Examples
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DkimSign
function DkimSign(mimeData: TChilkatBinData): Integer;
Introduced in version 9.5.0.71

Constructs and prepends a DKIM-Signature header to the MIME passed in mimeData. Prior to calling this method, your program must set both the DkimDomain and DkimSelector properties, and it must load a private key by calling SetDkimPrivateKey.

Returns 1 for success, 0 for failure.

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DkimVerify
function DkimVerify(sigIndex: Integer; mimeData: TChilkatBinData): Integer;
Introduced in version 9.5.0.71

Verifies the Nth DKIM-Signature header in the mimeData. (In most cases, there is only one signature.) The 1st signature is at sigIndex 0.

Important: Many anti-virus programs, such as AVG, will modify the MIME of an email as it is received. This will cause DKIM signature verification to fail because the body of the MIME is modified.

Returns 1 for success, 0 for failure.

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DomainKeySign
function DomainKeySign(mimeData: TChilkatBinData): Integer;
Introduced in version 9.5.0.71

Constructs and prepends a DomainKey-Signature header to the MIME passed in mimeData. Prior to calling this method, your program must set both the DomainKeyDomain and DomainKeySelector properties, and it must load a private key by calling SetDomainKeyPrivateKey.

Returns 1 for success, 0 for failure.

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DomainKeyVerify
function DomainKeyVerify(sigIndex: Integer; mimeData: TChilkatBinData): Integer;
Introduced in version 9.5.0.71

Verifies the Nth DomainKey-Signature header in the mimeData. (In most cases, there is only one signature.) The 1st signature is at sigIndex 0.

Important: Many anti-virus programs, such as AVG, will modify the MIME of an email as it is received. This will cause DomainKey signature verification to fail because the body of the MIME is modified.

Returns 1 for success, 0 for failure.

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LoadDkimPk
function LoadDkimPk(privateKey: WideString; optionalPassword: WideString): Integer;
This method is deprecated. It will be removed in a future version.

Loads an RSA private key to be used for creating a DKIM-Signature. Any valid RSA private key format that is not binary, such as PEM or XML, may be passed to this method. This method will automatically determine the format and parse it correctly. A password is only required if key is encrypted, such as for encrypted PEM.

Note: This method is deprecated. Use the SetDkimPrivateKey method instead.

Returns 1 for success, 0 for failure.

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LoadDkimPkBytes
function LoadDkimPkBytes(privateKeyDer: OleVariant; optionalPassword: WideString): Integer;
This method is deprecated. It will be removed in a future version.

Loads an RSA private key to be used for creating a DKIM-Signature. Any valid RSA private key binary format, such as DER, may be passed to this method. This method will automatically determine the format and parse it correctly. A password is only required if key is encrypted.

Note: This method is deprecated. Use the SetDkimPrivateKey method instead.

Returns 1 for success, 0 for failure.

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LoadDkimPkFile
function LoadDkimPkFile(privateKeyFilePath: WideString; optionalPassword: WideString): Integer;
This method is deprecated. It will be removed in a future version.

Loads an RSA private key file to be used for creating a DKIM-Signature. The file name contains any valid RSA private key format, such as DER, PKCS8, PEM, XML, etc. This method will automatically determine the format and parse it correctly. A password is only required if key is encrypted, such as for encrypted PEM or encrypted PKCS8.

Note: This method is deprecated. Use the SetDkimPrivateKey method instead.

Returns 1 for success, 0 for failure.

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LoadDomainKeyPk
function LoadDomainKeyPk(privateKey: WideString; optionalPassword: WideString): Integer;
This method is deprecated. It will be removed in a future version.

Loads an RSA private key to be used for creating a DomainKey-Signature. Any valid RSA private key format that is not binary, such as PEM or XML, may be passed to this method. This method will automatically determine the format and parse it correctly. A password is only required if key is encrypted, such as for encrypted PEM.

Note: This method is deprecated. Use the SetDomainKeyPrivateKey method instead.

Returns 1 for success, 0 for failure.

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LoadDomainKeyPkBytes
function LoadDomainKeyPkBytes(privateKeyDer: OleVariant; optionalPassword: WideString): Integer;
This method is deprecated. It will be removed in a future version.

Loads an RSA private key to be used for creating a DomainKey-Signature. Any valid RSA private key binary format, such as DER, may be passed to this method. This method will automatically determine the format and parse it correctly. A password is only required if key is encrypted.

Note: This method is deprecated. Use the SetDomainKeyPrivateKey method instead.

Returns 1 for success, 0 for failure.

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LoadDomainKeyPkFile
function LoadDomainKeyPkFile(privateKeyFilePath: WideString; optionalPassword: WideString): Integer;
This method is deprecated. It will be removed in a future version.

Loads an RSA private key file to be used for creating a DomainKey-Signature. The file name contains any valid RSA private key format, such as DER, PKCS8, PEM, XML, etc. This method will automatically determine the format and parse it correctly. A password is only required if key is encrypted, such as for encrypted PEM or encrypted PKCS8.

Note: This method is deprecated. Use the SetDomainKeyPrivateKey method instead.

Returns 1 for success, 0 for failure.

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LoadPublicKey
function LoadPublicKey(selector: WideString; domain: WideString; publicKey: WideString): Integer;

Caches a public key to be used for verifying DKIM and DomainKey signatures for a given selector and domain. The publicKey is a string containing an RSA public key in any text format, such as XML, PEM, etc. This method will automatically detect the format and load the public key correctly. This method is useful for testing DKIM and DomainKey verification when your public key has not yet been installed in DNS.

Returns 1 for success, 0 for failure.

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LoadPublicKeyFile
function LoadPublicKeyFile(selector: WideString; domain: WideString; publicKeyFilepath: WideString): Integer;

Caches a public key to be used for verifying DKIM and DomainKey signatures for a given selector and domain. The publicKeyFilepath is a filepath of an RSA public key in any format. This method will automatically detect the format and load the public key correctly. This method is useful for testing DKIM and DomainKey verification when your public key has not yet been installed in DNS.

Returns 1 for success, 0 for failure.

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NumDkimSignatures
function NumDkimSignatures(mimeData: OleVariant): Integer;

Returns the number of DKIM-Signature header fields found in mimeData.

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NumDomainKeySignatures
function NumDomainKeySignatures(mimeData: OleVariant): Integer;

Returns the number of DomainKey-Signature header fields found in mimeData.

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PrefetchPublicKey
function PrefetchPublicKey(selector: WideString; domain: WideString): Integer;

Useful if your application is going to verify many emails from a single domain (or a few domains). This eliminates the need to do a DNS lookup to fetch the public key each time an email's DKIM or DomainKey signature is verified.

This method may be called multiple times -- once for each selector/domain to be pre-fetched. The verify methods (VerifyDkimSignature and VerifyDomainKeySignature) will use a pre-fetched key if the selector and domain match.

Returns 1 for success, 0 for failure.

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PrefetchPublicKeyAsync (1)
function PrefetchPublicKeyAsync(selector: WideString; domain: WideString): TChilkatTask;

Creates an asynchronous task to call the PrefetchPublicKey method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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SetDkimPrivateKey
function SetDkimPrivateKey(privateKey: TPrivateKey): Integer;
Introduced in version 9.5.0.71

Sets the private key file to be used for creating a DKIM-Signature.

Returns 1 for success, 0 for failure.

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SetDomainKeyPrivateKey
function SetDomainKeyPrivateKey(privateKey: TPrivateKey): Integer;
Introduced in version 9.5.0.71

Sets the private key file to be used for creating a DomainKey-Signature.

Returns 1 for success, 0 for failure.

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UnlockComponent
function UnlockComponent(unlockCode: WideString): Integer;

Unlocks the component allowing for the full functionality to be used. If this method unexpectedly returns 0, examine the contents of the LastErrorText property to determine the reason for failure.

Returns 1 for success, 0 for failure.

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VerifyDkimSignature
function VerifyDkimSignature(sigIndex: Integer; mimeData: OleVariant): Integer;
This method is deprecated. It will be removed in a future version.

Verifies the Nth DKIM-Signature header in the mimeData. (In most cases, there is only one signature.) The 1st signature is at sigIndex 0.

Important: Many anti-virus programs, such as AVG, will modify the MIME of an email as it is received. This will cause DKIM signature verification to fail because the body of the MIME is modified.

Note: This method is deprecated. Use the DkimVerify method instead.

Returns 1 for success, 0 for failure.

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VerifyDkimSignatureAsync (1)
function VerifyDkimSignatureAsync(sigIndex: Integer; mimeData: OleVariant): TChilkatTask;
This method is deprecated. It will be removed in a future version.

Creates an asynchronous task to call the VerifyDkimSignature method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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VerifyDomainKeySignature
function VerifyDomainKeySignature(sigIndex: Integer; mimeData: OleVariant): Integer;
This method is deprecated. It will be removed in a future version.

Verifies the Nth DomainKey-Signature header in the mimeData. (In most cases, there is only one signature.) The 1st signature is at sigIndex 0.

Important: Many anti-virus programs, such as AVG, will modify the MIME of an email as it is received. This will cause DomainKey signature verification to fail because the body of the MIME is modified.

Note: This method is deprecated. Use the DomainKeyVerify method instead.

Returns 1 for success, 0 for failure.

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VerifyDomainKeySignatureAsync (1)
function VerifyDomainKeySignatureAsync(sigIndex: Integer; mimeData: OleVariant): TChilkatTask;
This method is deprecated. It will be removed in a future version.

Creates an asynchronous task to call the VerifyDomainKeySignature method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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Events

AbortCheck
procedure AbortCheck(ASender: TObject; out abort: Integer);

Provides the opportunity for a method call to be aborted. The AbortCheck event is fired periodically based on the value of the HeartbeatMs property. If HeartbeatMs is 0, then no AbortCheck events will fire. As an example, to fire 5 AbortCheck events per second, set the HeartbeatMs property equal to 200.

Delphi ActiveX Event callback implementation:

procedure TForm1.dkimENTRY_NAME(ASender: TObject;  out abort: Integer);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  dkim: TChilkatDkim;

begin
  dkim := TChilkatDkim.Create(Self);
  dkim.OnAbortCheck := dkimAbortCheck;
  // ...
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PercentDone
procedure PercentDone(ASender: TObject; pctDone: Integer; out abort: Integer);

Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This event is only fired when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For operations (Chilkat method calls) that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).

The PercentDone callback counts as an AbortCheck event. For method calls that complete quickly such that PercentDone events fire, it may be that AbortCheck events don't fire because the opportunity to abort is already provided in the PercentDone callback. For time consuming operations, where the amount of time between PercentDone callbacks are long, AbortCheck callbacks may be used to allow for the operation to be aborted in a more responsive manner.

The abort output argument provides a means for aborting the operation. Setting it to 1 will cause the method to abort and return a failed status (or whatever return value indicates failure).

Delphi ActiveX Event callback implementation:

procedure TForm1.dkimENTRY_NAME(ASender: TObject;  pctDone: Integer; out abort: Integer);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  dkim: TChilkatDkim;

begin
  dkim := TChilkatDkim.Create(Self);
  dkim.OnPercentDone := dkimPercentDone;
  // ...
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ProgressInfo
procedure ProgressInfo(ASender: TObject; const name: WideString; const value: WideString);

A general name/value event that provides information about what is happening during a method call. To find out what information is available, write code to handle this event and log the name/value pairs. Most are self-explanatory.

Delphi ActiveX Event callback implementation:

procedure TForm1.dkimENTRY_NAME(ASender: TObject;  const name: WideString; const value: WideString);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  dkim: TChilkatDkim;

begin
  dkim := TChilkatDkim.Create(Self);
  dkim.OnProgressInfo := dkimProgressInfo;
  // ...
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TaskCompleted
procedure TaskCompleted(ASender: TObject; const task: IChilkatTask);

Called in the background thread when an asynchronous task completes.

More Information and Examples

Delphi ActiveX Event callback implementation:

procedure TForm1.dkimENTRY_NAME(ASender: TObject;  const task: IChilkatTask);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  dkim: TChilkatDkim;

begin
  dkim := TChilkatDkim.Create(Self);
  dkim.OnTaskCompleted := dkimTaskCompleted;
  // ...
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