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ActiveX

pradeep_pc
pradeep_pc asked
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Hai Experts,

I have created an Activex component using Delphi5 .When I display this activex control in a browser and then press the backspace key the browser goes to the previous page.

The problem is that when we come back to the page containing the activex control again,all the data that I have entered previously will be lost. Is there any way to prevent this? Can you suggest a way to disable the backspace key with in an activex control?  
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Commented:
hi,
you will need to implement a message handler for your activex control to get the backspace message and control it so it doesnt send browser back.
below is a sample for twebbrowser as it has similar problems (as do all activex's in web pages it seems)you will need to modify it to suit you control.


unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, OleCtrls, SHDocVw_TLB,ActiveX;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    WebBrowser1: TWebBrowser;
    procedure Button1Click(Sender: TObject);
    procedure FormActivate(Sender: TObject);
    procedure FormDeactivate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private declarations }
  public
  procedure MyMessageHandler(var Msg: TMsg; var Handled: Boolean);

    { Public declarations }
  end;

var
  Form1: TForm1;
  FOleInPlaceActiveObject: IOleInPlaceActiveObject;
  SaveMessageHandler: TMessageEvent;


implementation

{$R *.DFM}

procedure TForm1.MyMessageHandler(var Msg: TMsg; var Handled: Boolean);
var
  iOIPAO: IOleInPlaceActiveObject;
  Dispatch: IDispatch;
begin
  { exit if we don't get back a webbrowser object }
  if WebBrowser1 = nil then
  begin
    Handled := False;
    Exit;
  end;

  Handled:=(IsDialogMessage(WebBrowser1.Handle, Msg) = True);

  if (Handled) and (not WebBrowser1.Busy) then
  begin
    if FOleInPlaceActiveObject = nil then
    begin
      Dispatch := WebBrowser1.Application_;
      if Dispatch <> nil then
      begin
        Dispatch.QueryInterface(IOleInPlaceActiveObject, iOIPAO);
        if iOIPAO <> nil then
          FOleInPlaceActiveObject := iOIPAO;
      end;
    end;

    if FOleInPlaceActiveObject <> nil then
      if ((Msg.message = WM_KEYDOWN) or (Msg.message = WM_KEYUP)) and
         ((Msg.wParam = VK_BACK) or (Msg.wParam = VK_LEFT) or (Msg.wParam = VK_RIGHT)) then
        //nothing - do not pass on Backspace, Left or Right arrows
      else
        FOleInPlaceActiveObject.TranslateAccelerator(Msg);
  end;
end;

procedure TForm1.FormActivate(Sender: TObject);
begin
  SaveMessageHandler := Application.OnMessage;
  Application.OnMessage := MyMessageHandler;

end;

procedure TForm1.FormDeactivate(Sender: TObject);
begin
Application.OnMessage := SaveMessageHandler;
end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
Application.OnMessage := SaveMessageHandler;
  FOleInPlaceActiveObject := nil;
end;

procedure TForm1.Button1Click(Sender: TObject);
var a,b,c,d:OleVariant;
begin
     WebBrowser1.Navigate(Edit1.Text,a,b,c,d);
end;

initialization
  OleInitialize(nil);

finalization
  OleUninitialize;

end.
Hi
I have a problem
i create a form with a TWebBrowser
so when i press CTRL+N , the System Create a new Internet Explorer
my pb is that i want to create a new TWebBrowser when i Press CTRL+N on The WebBRowSer
Can someone help me
Thx

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