Ronald you can use the IHTMLDocument2.onkeydown event to intercept and block a key.
to assign an event handler first you must create a procedure type using the IHTMLEventObj
as parameter.
THTMLProcEvent = procedure(Sender: TObject; Event: IHTMLEventObj) of object;
then you must create an class descendent from InterfacedObject
and IDispatch
to pass and process the events .
finally you can process the intercepted key in the onkeydown event in this way
Var
HTMLDocument2 : IHTMLDocument2;
begin
if Not Assigned(WebBrowser1.Document) then Exit;
HTMLDocument2:=(WebBrowser1.Document AS IHTMLDocument2);
if HTMLDocument2.parentWindow.event.keyCode=VK_F5 then //compare the key
begin
HTMLDocument2.parentWindow.event.cancelBubble:=True; //cancel the key
HTMLDocument2.parentWindow.event.keyCode :=0;
end;
end;
//check the full source code
unit Unit55;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, OleCtrls, SHDocVw, MSHTML;
type
//Create the procedure type to assign the event
THTMLProcEvent = procedure(Sender: TObject; Event: IHTMLEventObj) of object;
//Create a new class for manage the event from the twebbrowser
THTMLEventLink = class(TInterfacedObject, IDispatch)
private
FOnEvent: THTMLProcEvent;
private
constructor Create(Handler: THTMLProcEvent);
function GetTypeInfoCount(out Count: Integer): HResult; stdcall;
function GetTypeInfo(Index, LocaleID: Integer; out TypeInfo): HResult; stdcall;
function GetIDsOfNames(const IID: TGUID; Names: Pointer;
NameCount, LocaleID: Integer; DispIDs: Pointer): HResult; stdcall;
function Invoke(DispID: Integer; const IID: TGUID; LocaleID: Integer;
Flags: Word; var Params; VarResult, ExcepInfo, ArgErr: Pointer): HResult; stdcall;
public
property OnEvent: THTMLProcEvent read FOnEvent write FOnEvent;
end;
TForm55 = class(TForm)
WebBrowser1: TWebBrowser;
procedure FormShow(Sender: TObject);
procedure WebBrowser1NavigateComplete2(ASender: TObject; const pDisp: IDispatch; var URL: OleVariant);
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
FOnKeyDownConnector: THTMLEventLink; //pointer to the event handler
procedure WebBrowser1OnKeyDown(Sender: TObject; EventObjIfc: IHTMLEventObj);//the event handler
public
{ Public declarations }
end;
var
Form55: TForm55;
implementation
{$R *.dfm}
constructor THTMLEventLink.Create(Handler: THTMLProcEvent);
begin
inherited Create;
_AddRef;
FOnEvent := Handler;
end;
function THTMLEventLink.GetIDsOfNames(const IID: TGUID; Names: Pointer; NameCount, LocaleID: Integer; DispIDs: Pointer): HResult;
begin
Result := E_NOTIMPL;
end;
function THTMLEventLink.GetTypeInfo(Index, LocaleID: Integer; out TypeInfo): HResult;
begin
Result := E_NOTIMPL;
end;
function THTMLEventLink.GetTypeInfoCount(out Count: Integer): HResult;
begin
Result := E_NOTIMPL;
end;
function THTMLEventLink.Invoke(DispID: Integer; const IID: TGUID; LocaleID: Integer; Flags: Word; var Params; VarResult, ExcepInfo, ArgErr: Pointer): HResult;
var
HTMLEventObjIfc: IHTMLEventObj;
begin
Result := S_OK;
if Assigned(FOnEvent) then FOnEvent(Self, HTMLEventObjIfc);
end;
procedure TForm55.FormCreate(Sender: TObject);
begin
FOnKeyDownConnector := THTMLEventLink.Create(WebBrowser1OnKeyDown); //assign the address of the event handler
end;
procedure TForm55.WebBrowser1NavigateComplete2(ASender: TObject; const pDisp: IDispatch; var URL: OleVariant);
var
HTMLDocument2 : IHTMLDocument2;
begin
HTMLDocument2:=(WebBrowser1.Document AS IHTMLDocument2);
HTMLDocument2.onkeydown := FOnKeyDownConnector as IDispatch; //assign the event handler
end;
procedure TForm55.WebBrowser1OnKeyDown(Sender: TObject; EventObjIfc: IHTMLEventObj);
Var
HTMLDocument2 : IHTMLDocument2;
begin
//finally do your stuff here, in this case we will intercept and block the F5 key.
if Not Assigned(WebBrowser1.Document) then Exit;
HTMLDocument2:=(WebBrowser1.Document AS IHTMLDocument2);
if HTMLDocument2.parentWindow.event.keyCode=VK_F5 then
begin
HTMLDocument2.parentWindow.event.cancelBubble:=True;
HTMLDocument2.parentWindow.event.keyCode :=0;
end;
end;
procedure TForm55.FormShow(Sender: TObject);
begin
WebBrowser1.Navigate('www.google.com');
end;
end.